Stine Seed Request (09-063-01p) for an Extension of a 

Determination of Nonregulated Status to HCEM485

OECD Unique Identifier: 

HCEM485

Draft Environmental Assessment 

June 2012

Agency Contact 

Cindy Eck

Biotechnology Regulatory Services

4700 River Road 

USDA, APHIS 

Riverdale, MD 20737 

Fax: (301) 734-8669

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Mention of companies or commercial products in this report does not imply recommendation or endorsement by the 

U.S. Department of Agriculture over others not mentioned. USDA neither guarantees nor warrants the standard of any 

product mentioned. Product names are mentioned solely to report factually on available data and to provide specific 

information. 

This publication reports research involving pesticides. All uses of pesticides must be registered by appropriate State 

and/or Federal agencies before they can be recommended. 
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TABLE OF CONTENTS

Page

1 PURPOSE AND NEED..........................................................................................................1

1.1 Background .......................................................................................................................1

1.1.1 Request for an extension of nonregulated status........................................................1

1.1.2 Purpose of Product.....................................................................................................1

1.1.3 Coordinated Framework Review ...............................................................................1

1.2 Purpose and Need for APHIS Action................................................................................3

1.3 Public Involvement ...........................................................................................................4

2 AFFECTED ENVIRONMENT..............................................................................................6

2.1 Agricultural Production of Corn .......................................................................................6

2.1.1 Acreage and Area of Corn Production.......................................................................6

2.1.2 Agronomic Practices..................................................................................................9

2.1.3 Corn Seed Production ..............................................................................................18

2.1.4 Organic Corn Production .........................................................................................19

2.2 Physical Environment .....................................................................................................20

2.2.1 Soil Quality..............................................................................................................20

2.2.2 Water Resources ......................................................................................................23

2.2.3 Air Quality ...............................................................................................................26

2.2.4 Climate Change........................................................................................................28

2.3 Biological Resources.......................................................................................................29

2.3.1 Animal Communities...............................................................................................29

2.3.2 Plants Communities.................................................................................................31

2.3.3 Gene Flow and Weediness.......................................................................................36

2.3.4 Microorganisms .......................................................................................................38

2.3.5 Biodiversity..............................................................................................................40

2.4 Human Health .................................................................................................................43

2.5 Animal Feed ....................................................................................................................46

2.6 Socioeconomic ................................................................................................................48

2.6.1 Domestic Economic Environment ...........................................................................48

2.6.2 Trade Economic Environment .................................................................................52

3 ALTERNATIVES.................................................................................................................57

3.1 No Action Alternative: Continuation as a Regulated Article.........................................57

3.2 Preferred Alternative: Approve the Request for an Extension of a 

Determination of Nonregulated Status to Maize Line HCEM485 from Corn 

Event GA21 ....................................................................................................................57

3.3 Alternatives Considered But Rejected from Further Consideration ...............................58

3.3.1 Prohibit Any Maize Line HCEM485 Corn from Being Released ...........................58

3.3.2 Isolation Distance between Maize Line HCEM485 and Non-GE Corn 

Production and Geographical Restrictions..............................................................58
ii

3.3.3 Requirement of Testing for Maize Line HCEM485................................................59

3.4 Comparison of Alternatives ............................................................................................59

4 ENVIRONMENTAL CONSEQUENCES ...........................................................................62

4.1 Scope of Analysis............................................................................................................62

4.2 Agricultural Production of Corn .....................................................................................63

4.2.1 Acreage and Area of Corn Production.....................................................................63

4.2.2 Agronomic Practices................................................................................................63

4.2.3 Corn Seed Production ..............................................................................................65

4.2.4 Organic Corn Production .........................................................................................66

4.3 Physical Environment .....................................................................................................67

4.3.1 Soil Quality..............................................................................................................67

4.3.2 Water Resources ......................................................................................................68

4.3.3 Air Quality ...............................................................................................................69

4.3.4 Climate Change........................................................................................................71

4.4 Biological Resources.......................................................................................................72

4.4.1 Animal Communities...............................................................................................72

4.4.2 Plants Communities.................................................................................................74

4.4.3 Gene Flow and Weediness.......................................................................................77

4.4.4 Microorganisms .......................................................................................................78

4.4.5 Biodiversity..............................................................................................................80

4.5 Human Health .................................................................................................................83

4.5.1 No Action Alternative: Human Health ....................................................................83

4.5.2 Preferred Alternative: Human Health ......................................................................85

4.6 Animal Feed ....................................................................................................................86

4.6.1 No Action Alternative: Animal Feed.......................................................................86

4.6.2 Preferred Alternative: Animal Feed.........................................................................87

4.7 Socioeconomic Impacts...................................................................................................88

4.7.1 Domestic Economic Environment ...........................................................................88

4.7.2 Trade Economic Environment .................................................................................90

5 CUMULATIVE IMPACTS..................................................................................................93

5.1 Assumptions Used for Cumulative Impacts Analysis.....................................................93

5.2 Cumulative Effects..........................................................................................................94

5.2.1 Past and Present Actions..........................................................................................94

5.2.2 Reasonably Foreseeable Actions .............................................................................97

6 THREATENED AND ENDANGERED SPECIES ...........................................................100

6.1 Potential Effects of Maize Line HCEM485 on TES.....................................................102

6.2 Potential Effects of the Use of Glyphosate ...................................................................103

6.2.1 EPA Endangered Species Protection Program (ESPP)..........................................103

6.2.2 EPA TES Evaluation Process ................................................................................104

6.2.3 Ecological Risks of Glyphosate .............................................................................105
iii

6.2.4 Potential Impacts of Glyphosate Use in the Production of Corn...........................108

7 CONSIDERATION OF EXECUTIVE ORDERS, STANDARDS, AND TREATIES 

RELATING TO ENVIRONMENTAL IMPACTS............................................................109

7.1.1 Executive Orders with Domestic Implications......................................................109

7.1.2 International Implications......................................................................................111

7.1.3 Compliance with Clean Water Act and Clean Air Act..........................................113

7.1.4 Impacts on Unique Characteristics of Geographic Areas......................................113

7.1.5 National Historic Preservation Act (NHPA) of 1966 as Amended .......................115

8 LIST OF PREPARERS.......................................................................................................116

9 REFERENCES ...................................................................................................................117

Appendix A Federally Threatened and Endangered Species in Major Corn Production U.S. 

States and Puerto Rico

LIST OF FIGURES

No Page

Figure 1. The 2010 estimated amount of planted corn acreage by U.S. county in 

selected states. Estimates range from those counties that had less than 10,000 

acres of planted corn to those with 150,000 acres or more, and also reflect 

those counties not included in the estimation.............................................................. 7

Figure 2. The amount of planted and harvested corn acreage in millions of acres within 

the U.S. from 1991 through 2011. ............................................................................... 8

Figure 3. The percentage of U.S. planted corn acreage with GE varieties from 2000 

through 2011. All GE varieties are inclusive of insect-resistant-only 

(Bacillus thuringiensis (Bt)), herbicide-resistant-only, and stacked varieties 

(having both insect- and herbicide-resistant traits)...................................................... 8

Figure 4. The adoption, as a percentage of all planted corn, of herbicide-resistant corn 

(including herbicide-resistant-only and stacked herbicide- and insect-resistant 

varieties) in 2000, 2005, and 2011 of corn estimating program states. ....................... 9

Figure 5. Application to corn from 1996 to 2008 of glyphosate and other herbicides in 

terms of pounds per active ingredient per acre, and the percentage of 

herbicide-resistant planted corn................................................................................. 17

Figure 6. Percentage distribution of 2010 U.S. crop value among corn, soybean, hay, 

wheat, and other crops. Corn is among the most important field crops in the 

U.S. as its value of production was 41.7% of the total value of field crops in 

2010. .......................................................................................................................... 49

Figure 7. Value of U.S. corn crop as a percent of all U.S. field crops from 2001 to 

2010. Note the value of corn has increased since 2001, indicating its growing 

importance in U.S. agriculture................................................................................... 50
iv

Figure 8. U.S. corn per acre cost and value of production estimates in major ARMS 

corn- producing regions and the entire U.S. in 2010. Values presented 

exclude government payments. States comprising the regions include: 

Heartland (Illinois, Indiana, Iowa, Minnesota, Missouri, Nebraska, Ohio, and 

South Dakota), Northern Crescent (Michigan, Minnesota, Ohio, and 

Wisconsin), Northern Great Plains (Minnesota, Nebraska, North Dakota, and 

South Dakota), Prairie Gateway (Kansas, Nebraska, and Texas), Eastern 

Uplands (Missouri and Ohio), Fruitful Rim (Texas), and Southern Seaboard 

(Texas) resource regions (Fernandez-Cornejo and McBride, 2002). These 

regions vary in terms of land productivity and cost of production............................ 50

Figure 9. U.S. and world corn exports in million metric tons for marketing years 

2000/01 to 2010/11. Market years extend from September to August. The 

rest of the world major exporters include Argentina, Brazil, Canada, China, 

EU-27, India, Paraguay, Romania, Serbia, South Africa, Thailand, Ukraine, 

and Zambia as well as other smaller exporting countries. Note that U.S. 

percentage of corn exports in relation to overall world exports declined at the 

end of the last decade................................................................................................. 53

Figure 10. U.S. and world corn production in million metric tons for marketing years 

2000/01 to 2010/11. Market years extend from September to August. The 

rest of the world major producing countries include Argentina, Brazil, 

Canada, China, Egypt, EU-27, India, Indonesia, Mexico, Nigeria, Philippines, 

Romania, Serbia, South Africa, Thailand, Turkey, and the Ukraine. Note that 

U.S. production increased slightly while its percentage of overall world corn 

production declined in the last decade....................................................................... 55

Figure 11. U.S. and world corn consumption in million metric tons for marketing years 

2000/01 to 2010/11. Marketing years extend from September to August. 

The rest of the world major comsumers of corn include Brazil, Canada, 

China, Egypt, EU-27, India, Japan, Mexico, and South Africa. Note both 

U.S. and world corn consumption has increased over the last decade, 

although the U.S. percentage of overll world corn consumption has 

decreased.................................................................................................................... 56
v

LIST OF TABLES

No Page

Table 1. Total farm diesel fuel consumption estimate (in gallons per year) for no-till 

versus conventional till corn production in the Urbana, Illinois postal code. ........... 27

Table 2. U.S. glyphosate-resistant weeds as of December 2011. ............................................ 33

Table 3. U.S. states with more than one weed species with glyphosate resistance. ................ 34

Table 4. Largest importers of U.S. corn in the 2010/11 Season.............................................. 54

Table 5. World corn consumption for marketing years (August to September) 

2008/2009 to 2010/2011............................................................................................ 55

Table 6. Summary of issues of potential impacts and consequences of alternatives............... 60
vi

ACRONYMS AND ABBREVIATIONS

2mEPSPS double mutated 5-enolpyruvylshikimate-3-phosphate synthase 

ACCase acetyl-CoA Carboxylase 

AIA advanced informed agreement

ALS acetolactate synthase

AMS Agricultural Marketing Service

AMPA aminomethyl-phosphonic acid

AOSCA Association of Official Seed Certifying Agencies

ARMS Agricultural Resource Management Survey

ARS Agricultural Research Service

APHIS Animal and Plant Health Inspection Service

BMP best management practices

BNF Biotechnology Notification File

BRS Biotechnology Regulatory Service’s

Bt Bacillus thuringiensis

Ca2+ calcium ion

CAA Clean Air Act

CAS# Chemical Abstract Service Number

CBD Convention on Biological Diversity

CFR Code of Federal Regulations

CH4 methane

CO2 carbon dioxide

CO carbon monoxide

Coordinated Framework Coordinated Framework for the Regulation of Biotechnology

CP4 EPSPS CP4 5-enolpyruvylshikimate-3-phosphate synthase protein derived 

from the Agrobacterium sp. strain 

CRLF California red-legged frog

CWA Clean Water Act

DIMBOA 2,4-Dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one

DNA deoxyribonucleic acid

EA Environmental Assessment

ECOS Environmental Conservation Online System

EEC estimated environmental concentrations

EIS Environmental Impact Statement

EO Executive Order

EPA U.S. Environmental Protection Agency

EPSPS 5-enolpyruvylshikimate-3-phosphate synthase

ERS Economic Research Service

ESA Endangered Species Act

ESPP Endangered Species Protection Program

ESU evolutionarily significant unit

FALCPA Food Allergen Labeling and Consumer Protection Act of 2004

FDA U.S. Food and Drug Administration

Fe2+ iron ion

FFDCA Federal Food, Drug, and Cosmetic Act

FFP food, feed, or processing
vii

ACRONYMS AND ABBREVIATIONS (continued)

FIFRA Federal Insecticide, Fungicide, and Rodenticide Act

FR Federal Register

GE genetically engineered

GHG greenhouse gases

HED Health Effects Division

IP identity preservation

IPPC International Plant Protection Convention

ISPM International Standard for Phytosanitary Measure

K potassium

lb/Ac pounds per acre

lb ae/Ac pounds acid equivalent per acre

lb ai/Ac pounds active ingredient per acre

LMO living modified organism

LOC level of concern

Mn2+ manganese ion

N2O nitrous oxide

Na sodium

NAAQS National Ambient Air Quality Standards

NAPPO North American Plant Protection Organization

NASS National Agricultural Statistics Service

NCGA National Corn Growers’ Association

NEPA National Environmental Policy Act

NH4

+ ammonium ion

NHPA National Historic Preservation Act

NMFS National Marine Fisheries Service

NO2 nitrogen dioxide

NOP National Organic Program

NPS nonpoint source pollution

NRC National Research Council

NRCS Natural Resources Conservation Service

O3 ozone

OECD Organisation for Economic Co-operation and Development

Pb lead

PDP Pesticide Data Program

pH potential for hydrogen measure of acidity or alkalinity

PIPs plant-incorporated protectants

PM particulate matter

PM10 coarse particulate matter (PM) greater than 2.5 micrometers and 

less than 10 micrometers in diameter

PM2.5 fine particles less than 2.5 micrometers in diameter

POEA polyethoxylated tallow amine

PPE personal protective equipment

ppm parts per million

PPRA Plant Pest Risk Assessment
viii

ACRONYMS AND ABBREVIATIONS (continued)

PRA Plant Risk Analysis

RED Reregistration Eligibility Decision

RQ risk quotients

SDWA Safe Drinking Water Act

SIP State Implementation Plan

SO2 sulfur dioxide

SOC soil organic carbon

SOM soil organic matter

SSA Sole Source Aquifer

Stine Stine Seed Farm, Inc.

TES Threatened and Endangered Species

TSCA Toxic Substances Control Act

U.S. United States

U.S.C United States Code

USDA United States Department of Agriculture's

USFWS U.S. Fish & Wildlife Service

WPS Worker Protection Standard
1

1 PURPOSE AND NEED

1.1 Background

1.1.1 Request for an extension of nonregulated status

Stine Seed Farm, Inc. (hereafter Stine) of Adel, Iowa submitted a request (APHIS Number 09-

063-01p) to APHIS in 2009 for an extension of a determination of nonregulated status to Maize 

Line HCEM485 that expresses a modified corn epsps gene which confers resistance to the 

herbicide glyphosate. (Stine, 2011) The extension request cites the antecedent organism GA21 

(Monsanto, 1997) for which a petition for nonregulated status was approved on November 18, 

1997(62 F.R. 64350). In the event of an extension of a determination of nonregulated status, the 

nonregulated status for Maize Line HCEM485 would include Maize Line HCEM485, any 

progeny derived from crosses between Maize Line HCEM485 and conventional corn, and 

crosses of Maize Line HCEM485 with other biotechnology-derived corn that are no longer 

subject to the regulatory requirements of 7 CFR part 340 or the plant pest provisions of the Plant 

Protection Act. Maize Line HCEM485 is currently regulated under 7 CFR part 340. Interstate 

movements and field trials of Maize Line HCEM485 have been conducted under permits issued 

or notifications acknowledged by APHIS since 2005. Data resulting from these field trials are 

described in the extension request (Stine, 2011). 

1.1.2 Purpose of Product

The purpose of Maize Line HCEM485 is to provide another corn seed option that confers 

resistance to the herbicide glyphosate (Stine, 2011). Glyphosate works non-selectively on a wide 

range of plant species and may be applied at different growth stages; hence, it is easy to use, is a 

relatively low-cost herbicide, and facilitates conservation tillage farming practices while being 

relatively lower in toxicity to the environment than other pesticides (Gianessi, 2008; Duke and 

Powles, 2009). The potential commercial use of Maize Line HCEM485 would offer farmers an 

additional choice of glyphosate-resistant varieties for the control of weeds.

1.1.3 Coordinated Framework Review

Since 1986, the United States government has regulated genetically engineered (GE) organisms 

pursuant to a regulatory framework known as the Coordinated Framework for the Regulation of 

Biotechnology (Coordinated Framework) (51 FR 23302; 57 FR 22984). The Coordinated 

Framework, published by the Office of Science and Technology Policy, describes the 

comprehensive federal regulatory policy for ensuring the safety of biotechnology research and 

products and explains how federal agencies will use existing Federal statutes in a manner to 

ensure public health and environmental safety while maintaining regulatory flexibility to avoid 

impeding the growth of the biotechnology industry. The Coordinated Framework is based on 

several important guiding principles: (1) agencies should define those transgenic organisms 

subject to review to the extent permitted by their respective statutory authorities; (2) agencies are 

required to focus on the characteristics and risks of the biotechnology product, not the process by 

which it is created; (3) agencies are mandated to exercise oversight of GE organisms only when 

there is evidence of “unreasonable” risk.

The Coordinated Framework explains the regulatory roles and authorities for the three major 

agencies involved in regulating GE organisms: USDA’s Animal and Plant Health Inspection 
2

Service (APHIS), the Environmental Protection Agency (EPA), and the Food and Drug 

Administration (FDA).

USDA-APHIS

APHIS regulations at 7 Code of Federal Regulations (CFR) part 340, which were promulgated 

pursuant to authority granted by the Plant Protection Act, as amended (7 United States Code 

(U.S.C.) 7701–7772), regulate the introduction (importation, interstate movement, or release into 

the environment) of certain GE organisms and products. A GE organism is no longer subject to 

the plant pest provisions of the Plant Protection Act or to the regulatory requirements of 7 CFR 

part 340 when APHIS determines that it is unlikely to pose a plant pest risk. A GE organism is 

considered a regulated article if the donor organism, recipient organism, vector, or vector agent 

used in engineering the organism belongs to one of the taxa listed in the regulation (7 CFR 

340.2) and is also considered a plant pest. A GE organism is also regulated under Part 340 when 

APHIS has reason to believe that the GE organism may be a plant pest or APHIS does not have 

information to determine if the GE organism is unlikely to pose a plant pest risk. 

A person may petition the agency that a particular regulated article is unlikely to pose a plant 

pest risk, and, therefore, is no longer regulated under the plant pest provisions of the Plant 

Protection Act or the regulations at 7 CFR 340. A GE organism is no longer subject to the 

regulatory requirements of 7 CFR part 340 or the plant pest provisions of the Plant Protection 

Act when APHIS determines that it is unlikely to pose a plant pest risk. 

A person may also request that APHIS extend a determination of nonregulated status to other 

organisms under §340.6(e)(2) of the regulations. Such a request shall include information to 

establish the similarity of the antecedent organism and the regulated articles in question. 

Environmental Protection Agency

The EPA is responsible for regulating the sale, distribution, and use of pesticides, including 

pesticides that are produced by an organism through techniques of modern biotechnology. The 

EPA regulates plant incorporated protectants (PIPs) under the Federal Insecticide, Fungicide, and 

Rodenticide Act (FIFRA) (7 U.S.C. 136 et seq.) and certain biological control organisms under 

the Toxic Substances Control Act (TSCA) (15 U.S.C. 53 et seq.). Before planting a crop 

containing a PIP, a company must seek an experimental use permit from EPA. Commercial 

production of crops containing PIPs for purposes of seed increases and sale requires a FIFRA 

Section 3 registration with EPA. 

Under FIFRA (7 U.S.C. 136 et seq.), EPA regulates the use of pesticides (requiring registration 

of a pesticide for a specific use prior to distribution or sale of the pesticide for a proposed use 

pattern). EPA examines the ingredients of the pesticide; the particular site or crop on which it is 

to be used; the amount, frequency, and timing of its use; and storage and disposal practices. 

Prior to registration for a new use for a new or previously registered pesticide, EPA must 

determine through testing that the pesticide will not cause unreasonable adverse effects on 

humans, the environment, and non-target species when used in accordance with label 

instructions. EPA must also approve the language used on the pesticide label in accordance with 

40 CFR part 158. Once registered, a pesticide may not legally be used unless the use is 
3

consistent with the approved directions for use on the pesticide's label or labeling. The overall 

intent of the label is to provide clear directions for effective product performance while 

minimizing risks to human health and the environment. The Food Quality Protection Act 

(FQPA) of 1996 amended FIFRA, enabling EPA to implement periodic registration review of 

pesticides to ensure they are meeting current scientific and regulatory standards of safety and 

continue to have no unreasonable adverse effects (US-EPA, 2011d). 

EPA also sets tolerances for residues of pesticides on and in food and animal feed, or establishes 

an exemption from the requirement for a tolerance, under the Federal Food, Drug, and Cosmetic 

Act (FFDCA). EPA is required, before establishing pesticide tolerance, to reach a safety 

determination based on a finding of reasonable certainty of no harm under the FFDCA, as 

amended by the FQPA. FDA enforces the pesticide tolerances set by EPA.

Food and Drug Administration

FDA regulates GE organisms under the authority of the FFDCA (21 U.S.C. 301 et seq.). The 

FDA published its policy statement concerning regulation of products derived from new plant 

varieties, including those derived from genetic engineering, in the Federal Register on May 29, 

1992 (57 FR 22984). Under this policy, FDA implements a voluntary consultation process to 

ensure that human food and animal feed safety issues or other regulatory issues, such as labeling, 

are resolved before commercial distribution of bioengineered food. This voluntary consultation 

process provides a way for developers to receive assistance from FDA in complying with their 

obligations under Federal food safety laws prior to marketing.

More recently, in June 2006, FDA published recommendations in “Guidance for Industry: 

Recommendations for the Early Food Safety Evaluation of New Non-Pesticidal Proteins 

Produced by New Plant Varieties Intended for Food Use” (US-FDA, 2006) for establishing 

voluntary food safety evaluations for new non-pesticidal proteins produced by new plant 

varieties intended to be used as food, including bioengineered plants. Early food safety 

evaluations help make sure that potential food safety issues related to a new protein in a new 

plant variety are addressed early in development. These evaluations are not intended as a 

replacement for a biotechnology consultation with FDA, but the information may be used later in 

the biotechnology consultation.

Maize Line HCEM485 is within the scope of the FDA policy statement concerning regulation of 

products derived from new plant varieties, including those produced through genetic 

engineering. Stine initiated the consultation process with the FDA for the commercial 

distribution of Maize Line HCEM485 and submitted a safety and nutritional assessment of food 

and feed derived from Maize Line HCEM485 to the FDA in December 2010 in support of the 

consultation with the FDA for the commercial distribution of Maize Line HCEM485; as of 

publication of this EA, a determination is still pending (see http://www.accessdata.fda.gov 

/scripts/fcn/fcnNavigation.cfm?rpt=bioListing for a list of completed consultations).

1.2 Purpose and Need for APHIS Action

Under the authority of the plant pest provisions of the Plant Protection Act and 7 CFR part 340, 

APHIS has issued regulations for the safe development and use of GE organisms. A person may 

petition the agency that a particular regulated article is unlikely to pose a plant pest risk, and, 
4

therefore, is no longer regulated under the plant pest provisions of the Plant Protection Act or the 

regulations at 7 CFR 340. A GE organism is no longer subject to the regulatory requirements of 

7 CFR part 340 or the plant pest provisions of the Plant Protection Act when APHIS determines 

that it is unlikely to pose a plant pest risk. A person may also request that APHIS extend a 

determination of nonregulated status to other organisms under §340.6(e)(2) of the regulations.

Such a request shall include information to establish the similarity of the antecedent organism 

and the regulated articles in question. As required by § 340.6, APHIS must respond to 

petitioners who request a determination of the regulated status of GE organisms, including GE 

plants such as Maize Line HCEM485. When a request for an extension of nonregulated status is 

submitted, APHIS must make a determination if the GE organism is similar to an antecedent 

organism which has previously been determined to be unlikely to pose a plant pest risk. If 

APHIS determines based on its Plant Pest Risk Assessment (PPRA) of the antecedent organism 

that the genetically engineered organism identified in the extension request is unlikely to pose a 

plant pest risk, the genetically engineered organism is no longer subject to the plant pest 

provisions of the Plant Protection Act and 7 CFR part 340.

APHIS has prepared this Environmental Assessment (EA) to consider the potential 

environmental effects of an agency determination of nonregulated status consistent with Council 

of Environmental Quality’s National Environmental Policy Act (NEPA) regulations and the 

USDA and APHIS NEPA implementing regulations and procedures (40 CFR parts 1500-1508, 7 

CFR part 1b, and 7 CFR part 372). This EA has been prepared in order to specifically evaluate 

the effects on the quality of the human environment1 that may result from APHIS’ response to 

Stine’s extension request for a determination of nonregulated status of Maize Line HCEM485. 

1.3 Public Involvement

APHIS routinely seeks public comment on EAs prepared in response to petitions for 

nonregulated status of GE organisms. APHIS does this through a notice published in the Federal 

Register. The issues discussed in this EA were developed by considering the public concerns as 

well as issues raised in public comments submitted for other EAs of GE organisms, concerns 

raised in lawsuits, as well as those issues of concern that have been raised by various 

stakeholders. These issues, including those regarding the agricultural production of corn using 

various production methods and the environmental and food/feed safety of GE plants were 

addressed to analyze the potential environmental impacts of Maize Line HCEM485 corn. This 

EA will be available for public comment for a period of 30 days. Comments received by the end 

of the 30-day period will be analyzed and used to inform APHIS’ decision to extend the 

determination of nonregulated status of GA21 to Maize Line HCEM485 and to assist APHIS in 

determining whether an Environmental Impact Statement (EIS) is required prior to making a 

determination decision of the regulated status of this corn variety. 

Paragraph (e) of § 340.6 provides that APHIS will publish a notice in the Federal Register

announcing all preliminary decisions to extend determinations of nonregulated status for 30 days 

before the decisions become final and effective. In accordance with § 340.6(e) of the 

regulations, APHIS will publish a notice to inform the public of their preliminary decision to 

 1 Under NEPA regulations, the “human environment” includes “the natural and physical environment and the 

relationship of people with that environment” (40 CFR §1508.14).
5

extend the determination of nonregulated status of GA21 to Maize Line HCEM485 along with 

the extension request submitted by Stine and APHIS’ PPRA. Issues Considered

The list of resource areas considered in this EA were developed by APHIS through experience in 

considering public concerns and issues raised in public comments submitted for other EAs of GE 

organisms. The resource areas considered also address concerns raised in previous and unrelated 

lawsuits, as well as issues that have been raised by various stakeholders in the past. The resource 

areas considered in this EA can be categorized as follows: 

Agricultural Production Considerations:

• Acreage and Areas of Corn Production

• Agronomic/Cropping Practices

• Corn Seed Production

• Organic Corn Production

Environmental Considerations:

• Soil

• Water Resources

• Air Quality 

• Climate Change

• Animals

• Plants

• Gene Flow

• Microorganisms

• Biological Diversity

Human Health Considerations:

• Public Health

• Worker Safety

Livestock Health Considerations:

• Livestock Health/Animal Feed

Socioeconomic Considerations:

• Domestic Economic Environment 

• Trade Economic Environment
6

2 AFFECTED ENVIRONMENT

2.1 Agricultural Production of Corn

2.1.1 Acreage and Area of Corn Production

Corn (Zea mays, L.) is an annual grass cultivated in the U.S. in temperate regions with adequate 

frost-free days and moisture to promote plant maturity. It is native to the Americas and is 

referred to by much of the world as maize, a Native American name for the crop (Hoeft et al., 

2000). Corn may be successfully cultivated in many parts of the world, but the U.S. Midwest is 

the largest area with ideal conditions in the gently rolling topography, medium soil texture with 

high-moisture holding capacity, and temperature and rainfall regimes most favorable to corn 

production (Hoeft et al., 2000). Most of the corn produced in the U.S. is hybrid corn varieties 

adapted to local environmental and soil conditions. Generally, corn agronomic characteristics, 

such as optimal planting timeframe, disease and pest pressures, length of growing period, and 

water requirements, also vary by region (Neild and Newman, 1990; Hoeft et al., 2000; USDAERS, 2000; Koenning and Wiatrak, 2012). The geographic range of corn production in the U.S. 

has been expanded by growing the crop under irrigation and breeding programs to increase 

drought and cold tolerance, shorten length of growing period, and improve disease and pest 

resistance (Neild and Newman, 1990; Hoeft et al., 2000; Corn and Soybean Digest, 2009; 

Carena, 2010). 

Corn is the largest crop grown in the U.S. in terms of value (USGC, 2010), acreage planted, and 

geographic area of production. It is so adaptable it is cultivated in every continental U.S. state 

except Alaska, with winter breeding nurseries in Hawaii and Puerto Rico (Leidy, 2009; Alfaro, 

2011). The top corn producing states loosely known as the “Corn Belt” are Iowa, Illinois, 

Nebraska, Minnesota, South Dakota, Indiana, Kansas, Wisconsin, Ohio, and Missouri and

collectively produce over 80% of U.S. corn (USDA-NASS, 2011e). Figure 1 presents planted 

corn acreage in select states of the continental U.S. as of 2010 (USDA-NASS, 2011d). 

The amount of corn planted in the U.S. in 2011 totaled about 92.3 million acres, an increase of 

approximately 4.1 million acres over 2010 (USDA-NASS, 2011b). From 1991 to 2011, acreage 

planted with corn increased from just over 76.0 million acres to about 92.3 million acres, nearly 

a 21% increase (USDA-NASS, 2011i) (Figure 2). Over that 20 year span, U.S. production of 

field corn for grain increased from approximately 7.5 billion bushels (191 million metric tons) in 

1991 to approximately 12.4 billion bushels (315 million metric tons) in 2010, and average annual 

yield had increased approximately 41% from 108.6 bushels per acre in 1991 to 152.8 bushels per 

acre in 2010 (USDA-NASS, 2011e). At the same time, the use of corn for bioethanol production 

substantially contributed to the expansion in U.S. corn acreage. Between 2000 and 2009, U.S. 

ethanol production increased by nine billion gallons, accompanied with increased demand for 

feedstock (Wallander et al., 2011). Over the same period, the amount of harvested corn acreage 

increased by about 7.2 million acres, although, the change in corn production was not only 

driven by energy prices, but by other market forces such as exchange rates, increased global 

demand for meat, and weather conditions (USDA-OCE, 2011; Wallander et al., 2011). High

prices as a result of increased demand for ethanol feedstocks and meat are expected to increase 

corn production through 2020 (USDA-OCE, 2011). 
7

Source: (USDA-NASS, 2011d)

Figure 1. The 2010 estimated amount of planted corn acreage by U.S. county in selected 

states. Estimates range from those counties that had less than 10,000 acres of planted corn 

to those with 150,000 acres or more, and also reflect those counties not included in the 

estimation. 

Corn is also used for forage and silage animal feed. From 1991 to 2010, acreage devoted to 

growing corn for silage decreased from approximately 6.1 million acres to approximately 5.6 

million acres; however, annual production of corn silage also increased 32% over that period 

from approximately 81.2 million tons to nearly 107.3 million tons (USDA-NASS, 2011e). 

As of 2011, approximately 88% of all corn planted in the U.S. is GE. Forty-nine percent are

stacked (multiple) gene varieties having both herbicide- and insect-resistant traits (Figure 3) 

(USDA-ERS, 2011a). Herbicide-resistant varieties account for 23%, and insect-resistant-only 

cultivars comprised 16%. Other value-added corn GE traits include enhanced oil, starch, or 

nutritional characteristics and drought tolerance (USGC, 2010; USDA-APHIS, 2012). The first 

herbicide-resistant corn variety released in 1995 was glufosinate resistant and the first stacked 

hybrid varieties were released in 1997 (USDA-APHIS, 2012). The adoption of herbicideresistant corn was relatively low in 2000 (approximately 6%), yet all states surveyed as part of 

the Economic Research Service (ERS) corn estimating program steadily increased their adoption 

through 2011 (Figure 4) (USDA-ERS, 2011a). The amount of herbicide-resistant-only corn 

planted in the U.S. increased between 2000 and 2007 from 6% to 24% of all planted corn, yet 

has remained relatively steady since then at 22% to 23% of all planted corn (USDA-ERS, 

2011a). In addition, adoption of stacked corn varieties (those containing both herbicide- and 

insect-resistant traits) increased from 1% in 2000 to 49% in 2011 (USDA-ERS, 2011a).
8

Source: (USDA-NASS, 2011j)

Figure 2. The amount of planted and harvested corn acreage in millions of acres within 

the U.S. from 1991 through 2011. 

Source: (USDA-ERS, 2011a)

Figure 3. The percentage of U.S. planted corn acreage with GE varieties from 2000 

through 2011. All GE varieties are inclusive of insect-resistant-only (Bacillus thuringiensis

(Bt)), herbicide-resistant-only, and stacked varieties (having both insect- and herbicideresistant traits).
9

0

10

20

30

40

50

60

70

80

90

100

Percent of all corn planted

Survey State

2000 2005 2011

Source: (USDA-ERS, 2011a)

1 Estimates published individually beginning in 2005.

2 Includes all other states in the corn-estimating program.

Figure 4. The adoption, as a percentage of all planted corn, of herbicide-resistant corn 

(including herbicide-resistant-only and stacked herbicide- and insect-resistant varieties) in 

2000, 2005, and 2011 of corn estimating program states. 

Each year, the ERS updates its ten-year projections of supply and utilization for major field 

crops, including corn, soybeans, and wheat grown in the U.S. The ERS long-term projections 

are a conditional scenario based on specific assumptions about the macroeconomy, agricultural 

and trade policies, the weather, and international developments (USDA-OCE, 2011). Factors 

incorporated into the projection models include global economic growth, population trends, the 

value of the U.S. dollar and other currencies, oil prices, U.S. and international agricultural 

policy, the U.S. and international biofuels sector, livestock and meat trade, and prices (USDAOCE, 2011). Long-term projections show planted corn retaining its recent gains, maintaining 

between approximately 90 and 92 million acres a year through 2020 (USDA-OCE, 2011). The 

projected stability of U.S. planted corn acreage for the period is attributed to increased export 

competition, leveling of ethanol production based on corn, and continued higher price realization 

and yields, among other factors (USDA-OCE, 2011). Yields are projected to substantially 

increase; 2011 yields were 154.3 bushels per acre and are projected to increase to 180.0 bushels 

per acre by 2020 (USDA-OCE, 2011). 

2.1.2 Agronomic Practices

Agronomic practices associated with corn production include several crop management systems 

that are available to producers. Conventional farming in this document refers to any farming 

system where synthetic pesticides or fertilizers may be used. This type of farming broadly 
10

includes occasional use of pesticides and fertilizers to those that depend on regular inputs for 

successful crop production. This definition of conventional farming also includes the use of GE 

varieties that are no longer subject to the regulatory requirements of 7 CFR part 340 or the Plant 

Protection Act. Organic systems exclude certain production methods, such as synthetic 

agricultural inputs and GE crops, and are discussed in more detail below. Although specific crop 

production practices vary according to geographic area and end-use market, they commonly 

include tillage, irrigation, agricultural inputs such as fertilizers and pesticides, and crop rotation 

systems. The following introduces the basic cultivation requirements of corn and the agronomic 

practices commonly employed to produce corn in the U.S. More detailed information regarding 

the biology of corn may be obtained by consulting Stine’s Request for Extension of 

Determination of Nonregulated Status to the Additional Regulated Article: Maize Line 

HCEM485 (APHIS Number 09-063-01p) or APHIS’s Plant Pest Risk Assessment for Maize 

Line HCEM485 (Stine, 2010; USDA-APHIS, 2011b).

Cultivation

Corn (Zea mays ssp. mays L.) is a member of the Poaceae grass family (OECD, 2003). Corn 

was originally domesticated from various wild relatives in the teosinte taxa (Z. Mexicana) in 

South Mexico and Central America approximately 10,000 years ago (Matsuoka et al., 2002). 

Cultivated corn is sexually compatible with other members of the genus Zea, and to a much 

lesser degree with members of the genus Tripsacum grasses, the closest wild relative with which 

corn can interbreed. Teosinte grows in the tropical regions of Mexico, Guatemala, and 

Nicaragua. (USDA-APHIS, 2011b). Three species of Tripsacum (T. dactyloides, T. floridatum, 

and T. lanceolatum) are found in the continental U.S. (OECD, 2003), and two (T. fasciculatum

and T. latifolium) also occur in Puerto Rico (USDA-NRCS, 2011b). Corn is an annual plant with 

male tassels and female silks (i.e., it is monoecious) and is fertilized by windborne pollen, 

afterwards developing seeds on the cob that requires the assistance of humans to disperse

(OECD, 2003). It freely hybridizes among its many races, as well as with wild annual teosinte 

and a few Tripsacum grass species, although the latter has not been documented outside of 

experimental breeding (OECD, 2003).

The primary types of corn include dent, flint, flour, pop, and sweet corn, cultivars differing in 

their quantity, quality, and seed (endosperm) composition (Brown et al., 1985). Corn production 

in the U.S. is dominated by dent corn. Producers can choose from a large variety of corn lines 

developed from traditional breeding or GE systems; in 2010 it was estimated there were over 

6,000 traited2 and 1,000 conventional varieties from which to choose (Monsanto, 2011c). 

Corn is highly adaptable, tolerating widely divergent altitudes, sunlight, humidity, and 

temperature regimes (OECD, 2003). Corn is a warm weather crop grown in temperate latitudes 

due to the number of frost free days (110-115 days) and moisture needed for its production 

(OECD, 2003). The crop requires over 20 inches of rainfall to produce, but yields greatly 

increase in areas receiving over 30 inches of rainfall (Brown et al., 1985). Moisture availability 

within the week after silking is critical, as even one day of drought stress can reduce yields by 

8% (Duncan et al., 2007). Farmers in areas that predictably have high temperature stress and 

rainfall deficiencies during critical corn growth stages plant earlier and typically use earlier 

maturing varieties (Brown et al., 1985). Corn hybrids in the U.S. are traditionally classified into 

 2 Traited seeds are hybrid crop seeds that contain transgenic traits.
11

15 maturity groups, but actual maturation of a given hybrid can vary primarily based upon 

temperature and available moisture (Brown et al., 1985) 

Corn produces best on deep loamy soils, but can be grown in sandy to heavy clay settings 

(OECD, 2003; Ross et al., 2006). Optimal soil acidity (pH) for corn cultivation ranges from 5.8 

to 7.0, and key soil nutrients are nitrogen, phosphorous, potassium, calcium, magnesium, sulfur,

and micronutrients such as iron, manganese, zinc, and copper (Espinoza and Ross, 2006). Good 

drainage is also an important element, as areas with inadequate drainage limit yield (Ross et al., 

2006). Overall, adequate drainage is achieved when there is no standing water in a field 24 

hours following rainfall or irrigation (Tacker et al., 2006).

Depending upon the specific location, corn is typically planted from mid-March to the beginning 

of July; corn grown in more southern regions is planted earlier in the year than corn grown in 

northern regions (USDA-NASS, 1997). However, planting dates have moved earlier given the 

development of new maize cultivars that are better adapted to cooler soil conditions, although 

planting time fluctuates with wet springs (Kucharik, 2006). Planting date is important 

(especially for full season varieties); however, the critical factor for deciding when to plant is soil 

condition (i.e., temperature and moisture level), provided planting is accomplished within the 

timeframe for adequate maturation (Farnham, 2001a). If later planting is necessary, earlier 

maturing hybrids should be used to lower the potential of reduced yields.

Planting rates are determined by the germination percentage of the seed used, soil conditions,

and anticipated pest problems; producers usually plant more seed than the intended plant 

population goal (Farnham, 2001a). Plant populations are established based on a number of 

decisions and factors, including but not limited to soil properties, fertility, row spacing, yield 

goals, and corn cultivar. Carefully planned planting strategies and selection of corn cultivars that 

thrive in high populations and closer spacing may increase yields (Leidy, 2009; Stine, 2010). In 

a study in Illinois, Widdicombe and Thelen (2002) found that average corn yield increased as 

row width narrowed from 76 centimeters to 56 and 38 centimeters (approximately 2 feet 6 inches 

to 1 foot 10 inches and 1 foot 3 inches), and that the highest plant density evaluated (90,000 

plants per hectare) had the highest grain yield. However, in a study that compared row spacing 

in Iowa, Farnham (2001b) found that there was no statistical difference in yields between corn 

planted with 76 centimeter row spacing and that planted in 38 centimeter row spacing, although 

it was found that some hybrids tested had greater yield when planted in the decreased row 

spacing width, while other hybrids had greater yields in rows with wider spacing. 

The determination of when is the best time to harvest includes considerations such as the price of 

corn, potential yield, the length of the harvest period, weather, and equipment and labor costs, all 

of which can change during the course of the harvest season (Bitzer et al., No Date). Harvesting

corn is done mechanically and varies based on the region. For example, harvest in Kansas 

typically occurs from early September to mid-November, depending on the weather conditions, 

while harvest in North Dakota begins in late September and ends in late November (Olson and 

Sander, 1988; USDA-NASS, 1997). The extent of kernel damage to field corn while 

mechanically harvesting is dependent on its moisture content (Huitink, 2006); hence, corn ear 

moisture is factored into the determination of when to harvest. Field corn must be dried to 12% 

moisture content for storage extending longer than a few months (Gardisser, 2006); thus, 

economical harvest timing is dependent upon drying cost, any high moisture discounts levied 
12

upon sale, field loss, and damage penalties (Huitink, 2006). Corn harvested for silage is 

accomplished earlier than for grain, when standing plants still contain 65% to 70% moisture, just 

before physical maturity at the R7 growth stage (Lee et al., 2005).

Crop Rotation

Crop rotations are used to optimize soil nutrition and fertility, and reduce weeds, insects, and 

disease problems (Olson and Sander, 1988; Hoeft et al., 2000; Cartwright et al., 2006; McLeod 

and Studebaker, 2006; Leikam and Megel, 2007; Green and Owen, 2011). Crop rotation is the 

successive planting of different crops in the same field over a particular period of years. Crop 

rotation has two primary goals: sustaining the productivity of the agricultural system and 

maximizing economic returns (Hoeft et al., 2000). Sustaining the agricultural system is achieved 

by rotating crops that may improve soil health and fertility with more commercially beneficial 

“cash crops”. Crops in the legume family fix nitrogen in soil, improving the yield of following 

crops such as corn or wheat (Berglund and Helms, 2003). Moreover, the rotation of crops can 

effectively reduce disease, pest incidence, weediness, and selection pressure for weed resistance 

to herbicides (USDA-ERS, 1997b; Berglund and Helms, 2003). Crop rotation may also include 

fallow periods, or sowing with cover crops to prevent soil erosion and to provide livestock forage 

between cash crops (Hoeft et al., 2000; USDA-NRCS, 2010a). Maximizing economic returns is 

realized by rotating crops in a sequence that efficiently produces the most net returns for a 

producer over a single or multi-year period. Many factors at the individual farm level affect the 

choice of crop rotation system to use, ranging from soil type present in an individual field to 

expected commodity price, the need to hire labor, the price of fuel, the availability of funding to 

buy seed, and the price of agricultural inputs (Hoeft et al., 2000; Langemeier, 2007; Duffy, 

2011).

Crops used in rotation with corn vary regionally and include oats, peanut, soybean, wheat, rye,

and forage (USDA-APHIS, 2011b). In 2010, 71% of corn acreage in 19 surveyed states was 

under some form of rotation (USDA-NASS, 2011c). Cropland used for corn and soybean

production is nearly identical in many areas, such as Illinois, where over 90% of the cropped area 

is planted in a two-year corn-soybean rotation (Hoeft et al., 2000). Returns for producers from 

corn-soybean-corn are variable, dependent upon the price and projected yield of both corn and 

soybean for an individual operator (Stockton, 2007).

Recently, there has been an increase in continuous corn rotations given the profitability of corn 

production (USDA-ERS, 2011d) and the strong demand for grain (USDA-OCE, 2011). 

Continuous corn rotations require more fertilizer treatments to replace diminished soil nitrogen 

levels and more pesticide applications (Bernick, 2007; Laws, 2007; Erickson and Alexander, 

2008). Producers planting continuous corn are more likely to rely on GE varieties to compensate 

for the increased risk of corn pests and limited options of herbicides that come with growing corn 

over several consecutive years (Erickson and Alexander, 2008). Since more crop residue is 

produced, additional tillage prior to planting is necessary to prevent interference with mechanical 

planters or the application of fertilizer, and facilitate springtime warming of the soil (Bernick, 

2007; Laws, 2007; Erickson and Alexander, 2008). More corn residue accumulation also 

contributes to higher potential for disease and insect infestation in continuous corn rotations

(Laws, 2007; Nafziger, 2011). Crop residues are materials left in an agricultural field after the 
13

crop has been harvested, including stalks and stubble (stems), leaves, and seed pods (USDANRCS, 2005).

Corn seed left in a field after harvest can grow in a subsequent crop rotation and is known as 

“volunteer” corn (USDA-APHIS, 2011b). Subsection 2.3.2, Plants Communities, has a more 

detailed discussion of this issue and corresponding impacts analysis is found in Subsection 4.4.2, 

Plants Communities.

Tillage

Tillage is used to prepare a seedbed, address soil compaction, incorporate fertilizers and 

herbicides, manage water movement both within and out of a production field, control weeds, 

and reduce the incidence of insect pests and plant disease (Hoeft et al., 2000; Christensen, 2002; 

Fawcett and Towery, 2002; Tacker et al., 2006; Givens et al., 2009; NRC, 2010). A variety of 

tillage systems accomplishes these goals, with each system defined by the remaining plant 

residue left on the field. These residues aid in conserving soil moisture and reduce wind and 

water-induced soil erosion (USDA-ERS, 1997a; USDA-NRCS, 2005; Heatherly et al., 2009). 

Conventional tillage employs moldboard plows, heavy disks, and chisel plows that disturb soil 

and leaves less than 15% of crop residue on the surface (Heatherly et al., 2009; Towery and 

Werblow, 2010). Conservation tillage employs tools that disturb soil less and leaves more crop 

residues on the surface (at least 30%), whereas no-till farming only disturbs the soil for planting 

seed (USDA-NRCS, 2005; Towery and Werblow, 2010). The choice to till is dependent upon a 

variety of factors (Hoeft et al., 2000), such as:

• desired yields;

• soil type and moisture storage capacity;

• crop rotation pattern;

• prevalence of insect and weed pests;

• risk of soil compaction and erosion;

• the need for crop residue or animal waste disposal; and 

• management and time constraints. 

Tillage may increase yields in some cropping systems and soils, and not in others. For example, 

if a tillage system increases moisture infiltration, production potentially increases in response, 

but if it also increases denitrification or the incidence of plant diseases, crop yield would likely 

decrease (Hoeft et al., 2000). Tillage can impact the amount of agronomic inputs needed to 

maintain soil fertility and moisture and the amount of agricultural chemicals needed to control 

insect and weed pests (Olson and Sander, 1988; Hoeft et al., 2000; Cerdeira and Duke, 2006). 

According to USDA Agricultural Resource Management Survey (ARMS) 2010 data, the average 

residue remaining on the soil surface after planting corn was 34% and an average of 1.4 tillage 

operations per corn crop were conducted (USDA-ERS, 2011f). The plant residue coverage of 

the soil after planting increased dramatically to 65% for no-till corn production in 2005; 

however, no-till corn production represented only 24% of all corn acres planted in the U.S. 

(USDA-ERS, 2011f). In 2010, 62% of planted corn acreage in 19 surveyed states was dedicated 

to no-till or minimum till systems (USDA-NASS, 2011c). Increases in total acres dedicated to 

conservation tillage have been attributed to increased use of GE crops, reducing the need for 
14

mechanical weed control, although the change in tillage practices in corn was less dramatic than 

other crops such as soybean or cotton, as many growers of corn had already changed to 

conservation tillage systems as a means to reduce soil erosion (Fawcett and Towery, 2002; 

Givens et al., 2009).

Agricultural Inputs

Depending on the region and practices used, corn production includes inputs such as irrigation, 

fertilizer (e.g., synthetic fertilizers, manures, and composts containing nitrogen, phosphorus and 

potassium), pesticides (e.g., insecticides, herbicides), and fungicides (Olson and Sander, 1988; 

Hoeft et al., 2000; McLeod and Studebaker, 2006). Irrigation provides essential water for 

growth where rainfall is insufficient or erratic. This issue is discussed in detail in Subsection 

2.2.2, Water Resources, and the corresponding impacts analysis in Subsection 4.3.2. While most 

of the corn produced in the U.S. is grown without irrigation, approximately 14.2% of the 

harvested grain and silage corn acres were irrigated in 2008, the latest year with available 

national statistics reported (USDA-NASS, 2011e; USDA-NASS, 2011b).

Soil and foliar macronutrient applications to corn primarily include nitrogen, phosphorous 

(phosphate), potassium (potash), calcium, and sulfur, with other micronutrient supplements such 

as zinc, iron, and magnesium applied as needed (Espinoza and Ross, 2006). A 2010 survey of 19 

corn producing states conducted by National Agricultural Statistics Service (NASS) found 

nitrogen was the most widely used fertilizer on corn, applied to 97% of planted acres at an 

average rate of 140 pounds per acre (lb/Ac) (USDA-NASS, 2011c). Macronutrient phosphate 

was applied at an average rate of 60 lb/Ac to 78% of planted corn and potash was applied to 61% 

of planted acres at the rate of 79 lb/Ac. The survey found sulfur was applied less extensively at a 

rate of 13 lb/Ac to 15% of acres planted to corn (USDA-NASS, 2011c). 

A wide variety of pests can hinder corn production and many require agricultural pesticidal 

inputs for their control. Several groups and types of insects can feed on the seeds, roots, stalk, 

leaf, and ear of the corn plant, and can reduce yield if not adequately controlled. Major corn 

insect pests are the seed corn maggot (Hylemya platura), European (Ostrinia nubilalis Hübner)

and Southwestern (Diatraea grandiosella) corn stalk borer, the Western (Diabrotica virgifera 

virgifera LeConte), Northern (Diabrotica barberi Smith and Lawrence), and Southern

(Diabrotica undecimpunctata howardi Barber) rootworm, and earworms (Helicoverpa zea)

(Flanders et al., 2009). Additionally, there are soil nematodes (microscopic worms) of which the 

majority are beneficial; however, the few that are parasitic can constitute a significant 

management issue (SWCS, 2000) and are discussed in more detail in Subsection 2.3.4, 

Microorganisms, and corresponding impact analysis in Subsection 4.4.4. 

Before deciding to apply insecticides, producers should be relatively sure that yield increases 

will justify paying for the application cost (Higgins, 1997). Insect infestation thresholds for the 

most damaging pests have been established to indicate when control measures are actually 

necessary (Higgins, 1997). The thresholds are commonly based on number of insects found in 

field sampling surveys and/or in established standard defoliation thresholds, such as those 

provided by the National Information System of the Regional Integrated Pest Management 

Centers in pest management strategic plans (for example, see the Field Corn Pest Management 

Strategic Plan, North Central Region at http://www.ipmcenters.org/cropprofiles/index.cfm) (NSF 

Center for IPM, 2002). In 2010, insecticide active ingredients were applied to 12% of acres 
15

planted to corn in 19 surveyed states (USDA-NASS, 2011c). Tefluthrin was applied on average

to the most planted corn acreage at 3% to control corn rootworm, followed by bifenthrin (corn 

earworm, thrips), cyfluthrin (corn rootworm, earworm, European corn borer), lambdacyhalothrin (corn earworm, European corn borer), and tebupirimphos (corn rootworm, seed corn 

maggot), each equally treating an average 2% of planted corn acreage (USDA-NASS, 2011a). 

Producers can minimize the need to apply pesticides by choosing resistant cultivars (including 

GE varieties designed to kill particular pests), introducing beneficial pests that prey on targeted 

insects, and implementing crop rotation and tillage best management practices (BMPs) as 

discussed above.

Several plant diseases can also reduce corn yield (Cartwright et al., 2006), many of which are 

addressed with planting disease-resistant cultivars, and relatively few that may be treated with 

fungicides. The most common corn pathogens are fungi, viruses, bacteria, and nematodes. 

Factors contributing to crop disease include the susceptibility of the plant host, and a favorable 

air and soil environment (Stuckey et al., 1993). Diseases that afflict corn with significant 

potential for economic loss include fungal corn rusts, cornleaf blights, ear smuts, ear and kernel 

rot fungi, and maize mosaic viruses (Cartwright et al., 2006). In 2010, fungicides were applied 

to 8.0% of acres planted to corn in 19 survey states (USDA-NASS, 2011c). 

Weeds are the most important pest complex that interferes with maximum yield and profitability 

in U.S. agriculture; therefore, effective weed management is critically important to sustainable

production (Owen et al., 2011). Weeds have the most impact on potential corn yields in the first 

six weeks after planting and can reduce yields by as much as 50% if they are uncontrolled (Smith 

and Scott, 2006). Practices to reduce the incidence of weeds include tillage, crop rotation, 

intercropping, the use of ground covers and mulches, flame weeding, and the application of 

herbicides (Gunsolus, 2006; Hedtke et al., 2006; Smith and Scott, 2006; CropsReview, 2011; 

USDA-NASS, 2011c). In addition, no-till practices also reduce weed occurrence by minimizing 

soil disturbance that promotes weed seed germination (University of California, 2009). 

Although cultivation controls weeds, it prunes corn roots in later growth stages, potentially 

reducing yields. This fact and the availability of better herbicide technology have driven 

producers to turn to more chemical weed control than cultivation in corn production (Smith and 

Scott, 2006). Herbicides have different ways of acting on plant physiology (i.e., modes of 

action) to affect the health of a given plant. Some common modes of herbicide action include 

amino acid inhibitors such as glyphosate and imazethapyr, chlorophyll pigment inhibitors like

atrazine, auxin growth regulators including dicamba and 2,4-D, long chain fatty acid inhibitors 

such as acetochlor and s-metolachlor, and glutamine synthase inhibitors such as glufosinate

(University of Wisconsin, No Date). Herbicides are applied pre-emergence to a crop (i.e.,

“preplant burndown”) and post-emergence. If herbicides were not available, it is estimated that 

approximately 20% of yields would be lost to weeds, assuming only tillage and hand weeding 

remain as the weed management tactic (Gianessi and Reigner, 2007). Hand and mechanical 

tillage methods to control weeds damage crops, prune roots, and increase plant susceptibility to 

some diseases, which decrease yield; furthermore, any delays in mechanical weed control due to 

events such as weather increases the chance for crop damage when tillage can resume, or may 

cause the loss of crops in sections or an entire field (Gianessi and Reigner, 2007).
16

In 2010, more than 98% of corn acres in 19 surveyed states (Arkansas, Illinois, Indiana, Iowa, 

Kansas, Kentucky, Louisiana, Michigan, Minnesota, Mississippi, Missouri, Nebraska, North 

Carolina, North Dakota, Ohio, South Dakota, Tennessee, Virginia, and Wisconsin) were treated 

with herbicides and more than two-thirds of the total pesticides applied to corn in those states 

were herbicides (USDA-NASS, 2011c). Of the latter, 66% of the 2010 corn acreage in the 

surveyed states was treated with glyphosate, 61% with atrazine, and 25% with acetochlor 

(USDA-NASS, 2011c). Compared to data collected in a 2005 survey from the same 19 states, 

glyphosate-treated planted corn acres increased 35%, atrazine was applied to 5% fewer acres, 

and acetochlor treatments of planted acres increased 2% (USDA-NASS, 2007a; USDA-NASS, 

2011c). The dramatic increase in the use of glyphosate as a consequence of expanded adoption 

of the GE trait in corn production is primarily attributed to the herbicide’s effective and efficient 

weed control as a non-selective herbicide (Owen et al., 2011). Its relatively low cost and 

simplicity of use, coupled with minimal animal toxicological and environmental impact, as well 

as its support of conservation tillage practices makes it a desirable weed management tool and 

reduces overall production costs (Duke and Powles, 2009; NRC, 2010; Green and Owen, 2011).

Herbicide usage trends since the adoption of GE technologies are the subject of much debate, 

with initial assessments indicating a decline in herbicide use in the early years of herbicideresistant crop production (Carpenter et al., 2002), while some argue that an increase in the 

volume of herbicide usage followed as the technology spread (Benbrook, 2009). Others report a 

continuing decline in herbicide use with the adoption of GE crops (Fernandez-Cornejo and 

Caswell, 2006) and in the amount of herbicide active ingredients applied to corn (Brookes and 

Barfoot, 2010). The contradictory findings have been attributed to the different measurement 

approaches used by researchers, the manner in which different factors affecting pesticide use 

such as weather or cropping patterns are controlled for, and how collected data is statistically 

analyzed (NRC, 2010). 

Another observed herbicide trend since the adoption of GE corn has been a substantial reduction 

in the diversity of herbicides used in corn production (Young, 2006). The use of other herbicides 

has declined significantly and it is estimated that 34% of corn acres receive only glyphosate for 

weed management (NRC, 2010; Owen, 2011) (Figure 5). Weed management is herbicide-based 

in both GE and conventional corn production; however, due to the effectiveness of glyphosate 

and the ease of its use, the adoption of GE glyphosate-resistant crops for weed management was 

the most rapid implementation of a crop technology in the history of agriculture (Duke, 2011). 

This trend and its potential impacts to herbicide-resistant weed development are discussed in 

Subsection 2.3.2, Plants Communities.
17

Source: (NRC, 2010)

Figure 5. Application to corn from 1996 to 2008 of glyphosate and other herbicides in 

terms of pounds per active ingredient per acre, and the percentage of herbicide-resistant 

planted corn.

Maize Line HCEM485 was developed to provide growers another alternative in glyphosateresistant corn cultivars (Stine, 2011). The following presents a summary of the current use and 

registration of the herbicide glyphosate.

Glyphosate is a non-selective herbicide and plant growth regulator approved for use on a wide 

variety of food and non-food field crops and wherever total vegetation control is desired (USEPA, 1993b). First registered for use in 1974, glyphosate has been subsequently reregistered in 

the 1993 Glyphosate Registration Eligibility Decision (US-EPA, 1993b). Glyphosate is 

currently under registration review with a decision expected in 2015 (US-EPA, 2009a). The 

chemical is formulated in several salt, acid, and ammonium compounds and is registered for use 

on fruit, vegetables, field crops, lawns and residential settings, industrial rights of way, and for 

aquatic weed control (US-EPA, 2009a). 

Glyphosate, which is in the glycine herbicide category, inhibits EPSPS production in plants 

(Senseman, 2007). Inhibition of EPSPS reduces the presence of key amino acids required for 

protein synthesis or necessary for certain metabolic pathways required for plant growth. It 

absorbs directly through plant leaves and rapidly spreads throughout the plant. Surfactants are 

used in the herbicide formulation to enable greater glyphosate penetration into the leaves 

(Senseman, 2007). The environmental risk of the surfactant polyethoxylated tallow amine 

(POEA) in certain glyphosate products will be assessed by the EPA in their current registration 

review for glyphosate (US-EPA, 2009a). Glyphosate can be tank mixed with other herbicides to 

minimize the potential for selection of herbicide-resistant weeds and provide control over a 

diversity of weed pests (Thompson and Peterson, 2005; Boerboom and Owen, 2006; Gunsolus, 

2006; Owen, 2010). 
18

2.1.3 Corn Seed Production

Cornfields in the U.S. are generally planted with hybrid seed because hybrid vigor results in 

higher and more consistent grain yields. Approximately 50 to 60 million bushels (1.3 to 1.5 

million metric tons) of seed corn are needed annually, which seed companies generally exceed 

by producing 30 to 40% more than is needed (Wych, 1988).

Seed corn production occurs regionally with the seed for hybrids adapted to the conditions in the 

southern U.S. grown in the South and similarly, hybrids adapted to the northern U.S. grown in 

the North (Stefferud, 2007). Iowa, Nebraska, Indiana, and Illinois represent the region where the 

most seed corn is produced (Bennett, 2011). Seed corn is also grown during the winter in 

nurseries in Hawaii, Puerto Rico, Chile, and Argentina (Leidy, 2009; Alfaro, 2011), where 

growing conditions maximize corn growth and productivity. Corn is grown in these nurseries to 

supplement low seed supplies or provide enough seed of the elite hybrids in greatest demand for 

planting the next season in the mainland U.S. (Beckman, 2011). Acreage devoted to corn seed 

production in winter nurseries is comparatively small. For example, only approximately 7,100 

acres were under cultivation for all crop seed production in Hawaii in the 2010/2011 crop year, 

compared to 91.9 million acres of U.S. planted corn in 2011 (USDA-NASS, 2011h). 

The U.S. Federal Seed Act of 1939 recognizes seed certification and official certifying agencies. 

Implementing regulations further recognize land history, field isolation, and varietal purity 

standards for seed. Seed certification is important to ensure the high quality of corn seed and is 

accomplished by a wide range of programs which include field inspections and laboratory testing

(Bradford, 2006; AOSCA, 2011). Various seed associations have standards to help maintain the 

quality of corn seed. New seed varieties are evaluated by review boards to determine if the 

varieties meet the eligibility requirements for certification. The Association of Official Seed 

Certifying Agencies (AOSCA, No Date) defines the classes of seed as follows:

• Breeder seed is directly controlled by the plant breeder that developed the variety.

• Foundation seed is the progeny of Breeder or Foundation seed that is handled to most 

nearly maintain specific genetic identity and purity.

• Registered seed is a progeny of Breeder or Foundation seed that is so handled as to 

maintain satisfactory genetic identity and purity.

• Certified seed is the progeny of Breeder, Foundation, or Registered seed that is so 

handled as to maintain satisfactory genetic identity and purity.

Identity preservation (IP) is distinguished from seed certification as its focus is a rigorous 

process to maintain the genetic purity of seed stocks (Sundstrom et al., 2002; Bradford, 2006; 

Bennett, 2011). IP is accomplished by following a strict regime of management practices such 

as seed purity standards, recognizing field history to insure eligibility of the field for seed corn 

production, meeting field isolation standards to protect from the introgression of pollen from 

other corn varieties, seed sampling and testing, and record maintenance and labeling (Sundstrom 

et al., 2002). 

Both certification programs and IP have been extremely successful in maintaining the purity and 

high quality of seed corn product and have provided oversight during the entire process from 

planting to bagging of the seed corn.
19

2.1.4 Organic Corn Production

In the U.S., only products produced using specific methods and certified under the USDA’s 

Agricultural Marketing Service (AMS) National Organic Program (NOP) definition of organic 

farming can be marketed and labeled as “organic” (USDA-AMS, 2008). Organic certification is 

a process-based certification, not a certification of the end product; the certification process

specifies and audits the methods and procedures by which the product is produced. 

In accordance with NOP, an accredited organic certifying agent conducts an annual review of the 

certified operation’s organic system plan and makes on-site inspections of the certified operation 

and its records. Organic growers must maintain records to show that production and handling 

procedures comply with USDA organic standards. 

The NOP regulations preclude the use of excluded methods. The NOP provides the following 

guidance under 7 CFR Section 205.105:

...to be sold or labeled as “100 percent organic”, “organic” or “made with organic 

(specified ingredients or group(s)),” the product must be produced and handled without 

the use of:...

(a) Synthetic substances and ingredients,...

(e) Excluded methods,...

Excluded methods are then defined at 7 CFR Section 205.2 as:

A variety of methods used to genetically modify organisms or influence their growth and 

development by means that are not possible under natural conditions or processes and are 

not considered compatible with organic production. Such methods include cell fusion, 

microencapsulation and macroencapsulation, and recombinant deoxyribonucleic acid 

(DNA) technology (including gene deletion, gene doubling, introducing a foreign gene, 

and changing the positions of genes when achieved by recombinant DNA technology). 

Such methods do not include the use of traditional breeding, conjugation, fermentation, 

hybridization, in vitro fertilization, or tissue culture.

Organic farming operations, as described by the NOP, are required to have distinct, defined 

boundaries and buffer zones to prevent unintended contact with excluded methods from 

adjoining land that is not under organic management. Organic production operations must also 

develop and maintain an organic production system plan approved by their accredited certifying 

agent. This plan enables the production operation to achieve and document compliance with the 

National Organic Standards, including the prohibition on the use of excluded methods (USDAAMS, 2008). 

Common practices organic growers may use to exclude GE products include planting only 

organic seed, planting earlier or later than neighboring farmers who may be using GE crops so 

that the crops will flower at different times, and employing adequate isolation distances between 

the organic fields and the fields of neighbors to minimize the chance that pollen will be carried 

between the fields (NCAT, 2003). Although the National Organic Standards prohibit the use of 

excluded methods, they do not require testing of inputs or products for the presence of excluded 

methods. The presence of a detectable residue of a product of excluded methods alone does not 
20

necessarily constitute a violation of the National Organic Standards (USDA-AMS, 2008). The 

current NOP regulations do not specify an acceptable threshold level for the adventitious 

presence of GE materials in an organic-labeled product. The unintentional presence of the 

products of excluded methods will not affect the status of an organic product or operation when 

the operation has not used excluded methods and has taken reasonable steps to avoid contact 

with the products of excluded methods as detailed in their approved organic system plan (Ronald 

and Fouche, 2006; USDA-AMS, 2008).

Organic corn production practices include crop rotation, use of cover crops and green manures, 

animal manures, application of rock minerals such as lime, other soil additives, mechanical weed 

control, and biological control of pests (Kuepper, 2002). Weed control can be accomplished 

with delayed seeding to avoid spring weeds, applying fertilizer to growing plants to outcompete 

weeds, increasing seeding rates, sowing cover crops, crop rotation, intercropping, flame 

weeding, hand weeding, and mechanical means (e.g., tillage) (Halford et al., 2001; Kuepper, 

2002; Heverton et al., 2008; Green and Owen, 2011). Other pest control is accomplished with 

application of natural pesticides, integrated pest management techniques such as introduction of 

beneficial organisms in the form of soil predator and parasitic organisms, and practices such as 

those described for weed control (NCAT, 2003). Organic crop production historically has also 

utilized mulch and ridge tillage practices (NCAT, 2003). However, while no-till organic corn 

production has been generally difficult and possibly unsustainable due to weed pests, broadcast 

flame weeding may be a viable alternative to chemical weed control (Heverton et al., 2008).

NASS and ERS recently reported the organic crop production data collected in 2008 (USDAERS, 2010a; USDA-NASS, 2010a). In that year, 143,432 acres of organic corn on 2,146 farms 

in 39 states were harvested for grain or seed; furthermore, 24,871 acres of organic corn on 664 

farms in 27 states were harvested as silage or greenchop; greenchop is the harvest of a crop 

without allowing it to dry in the field. Iowa, Michigan, Minnesota, New York, and Wisconsin

were the only states with more than 10,000 acres of organic corn harvested for grain or seed 

while only Wisconsin had more than 6,000 acres of organic corn grown for silage or greenchop.

In contrast, Iowa, Michigan, Minnesota, New York, and Wisconsin combined had approximately 

29 million acres of corn harvested in 2008 (USDA-NASS, 2008a). In 2008, organic corn 

harvested for grain or seed consisted of about 0.2% of total U.S. corn production (USDA-NASS, 

2010a; USDA-NASS, 2011e).

2.2 Physical Environment

2.2.1 Soil Quality 

Soil consists of solids (minerals and organic matter), liquid, and gases. This body of inorganic 

and organic matter is home to a wide variety of fungi, bacteria, and arthropods, as well as the 

growth medium for terrestrial plant life (USDA-NRCS, 2004). Soil is characterized by its layers 

that can be distinguished from the initial parent material due to additions, losses, transfers, and 

transformations of energy and matter (USDA-NRCS, 1999b). It is further distinguished by its 

ability to support rooted plants in a natural environment. Soil plays a key role in determining the 

capacity of a site for biomass vigor and production in terms of physical support, air, water, 

temperature moderation, protection from toxins, and nutrient availability. Soils also determine a 

site’s susceptibility to erosion by wind and water, and a site’s flood attenuation capacity.
21

Soil properties change over time: temperature, acidity or alkalinity (pH), soluble salts, amount of 

organic matter, the carbon-nitrogen ratio, and numbers of microorganisms and soil fauna all 

change seasonally as well as over extended periods of time (USDA-NRCS, 1999b). Soil texture 

and organic matter levels directly influence soil shear strength, nutrient holding capacity, and 

permeability. Soil taxonomy was established to classify soils according to the relationship 

between soils and the factors responsible for their character (USDA-NRCS, 1999b). Soils are 

organized into four levels of classification, the highest being the soil order. Soils are 

differentiated based on characteristics such as particle size, texture, and color, and classified 

taxonomically into soil orders based on observable properties such as organic matter content and 

degree of soil profile development (USDA-NRCS, 2010c). The Natural Resources Conservation 

Service (NRCS) maintains soil maps on a county level for the entire U.S. and its territories.

Corn is able to grow in a wide variety of soils with irrigation, but grows best in deep, welldrained, medium- to coarse-textured soils (Ross et al., 2006; Wright et al., 2009). Corn needs a 

variety of nutrients: primarily nitrogen, phosphorus, and potassium, as well as secondary 

nutrients such as calcium, magnesium, and sulfur at various levels (Espinoza and Ross, 2006). 

Corn also requires smaller amounts of micronutrients such as iron, zinc, copper, boron, 

manganese, molybdenum, and cobalt. The availability of nutrients is influenced by the soil pH, 

with the desirable range for corn of 5.8 to 7.0. Soil with a pH below 5.7 generally requires 

amendment with lime (Espinoza and Ross, 2006). 

Land management practices for corn cultivation can affect soil quality. While management 

practices such as tillage, fertilization, the use of pesticides, and other management tools can 

improve soil health, they can also cause substantial damage if not properly used. Several 

concerns relating to agricultural practices include increased erosion, soil compaction, 

degradation of soil structure, nutrient loss, increased salinity, change in pH, and reduced 

biological activity (USDA-NRCS, 2001). 

As discussed in Subsection 2.1.2, Agronomic Practices, conventional and conservation tillage are 

practiced in the cultivation of corn. Reducing excessive tillage through practices such as 

conservation tillage minimizes the loss of organic matter and protects the soil surface by leaving 

plant residue on the surface. Management of the residue is one of the most effective 

conservation methods to reduce wind and water soil erosion, and also benefits air and water 

quality and wildlife (USDA-NRCS, 2006a). 

Residue management that uses intensive tillage and leaves low amounts of crop residue on the 

surface results in greater losses of soil organic matter (SOM). Intensive tillage turns the soil over 

and buries the majority of the residue, stimulating microbial activity and increasing the rate of 

residue breakdown (USDA-NRCS, 1996). The residues left after conservation tillage increases 

organic matter and improves infiltration, soil stability and structure, and soil microorganism 

habitat (Fawcett and Caruana, 2001; USDA-NRCS, 2006b). Organic matter is probably the most 

vital component in maintaining soil quality (USDA-NRCS, 1996): 

• it maintains soil stability and structure;

• reduces the potential for erosion;

• provides energy for microorganisms;

• improves infiltration and water holding capacity;
22

• is important in nutrient cycling;

• increases cation exchange capacity3; and

• breaks down pesticides.

The increased residue from conservation tillage increases SOM in the top three inches of the soil 

and protects the surface from erosion while maintaining water-conducting pores. Soil aggregates 

in conservation tillage systems are more stable than that of conventional tillage due to the 

products of SOM decomposition and the presence of soil bacteria and fungal hyphae 

(filamentous structures that compose the main growth) that bind aggregates and soil particles 

together (USDA-NRCS, 1996). Although soil erosion rates in crop production are dependent on 

numerous local conditions such as soil texture and crop, a comparison of 39 studies contrasting 

conventional and no-till practices found that, on average, no-till practices were 20 to 488 times 

more effective in reducing erosion than conventional tillage (Montgomery, 2007). This 

reduction enables soil production to nearly replace soil losses from erosion. From 1982 through 

2003, erosion on U.S. cropland dropped from 3.1 billion tons per year to 1.7 billion tons per year 

(USDA-NRCS, 2006a). This can partially be attributed to the increased effectiveness of weed 

control through the use of herbicides and corresponding reduction in the need for mechanical 

weed control that facilitates no-till crop production (Carpenter et al., 2002).

Conservation tillage also minimizes soil compaction due to the reduced number of tillage trips. 

Other methods to improve soil quality includes careful management of fertilizers and pesticides; 

use of cover crops to increase plant diversity and limit the time soil is exposed to wind and rain; 

and increased landscape diversity with buffer strips, contour strips, wind breaks, crop rotations, 

and varying tillage practices (USDA-NRCS, 2006b). 

While conservation tillage does have several benefits for soil health, some management concerns 

are associated with its use. Under no-till practices, soil compaction may become a problem as 

tillage is useful for breaking up compacted areas (USDA-NRCS, 1996). Likewise, not all soils 

(such as wet and heavy clay soils) are suited for no-till. Also, no-till practices may lead to 

increased pest occurrences that conventional tillage is better suited to managing (NRC, 2010).

There are a multitude of organisms associated with soils ranging from microorganisms to larger 

organisms such as worms and insects. The microorganisms that make up the soil community 

include bacteria, fungi, protozoa, and nematodes that are responsible for a wide range of 

activities that impact soil health and plant growth. Decomposers such as bacteria, actinomycetes 

(filamentous bacteria), and saprophytic fungi degrade plant and animal remains, organic 

materials, and some pesticides (USDA-NRCS, 2004). Other organisms, such as protozoa, mites, 

and nematodes, consume decomposer microbes and release macro- and micronutrients, making 

them available for plant usage. Another important group of soil microorganisms are the 

mutualists. These are the mycorrhizal fungi, nitrogen-fixing bacteria, and some free-living 

microbes that have co-evolved with plants that supply nutrients to and obtain food from their 

plant hosts (USDA-NRCS, 2004). Plants also have both direct and indirect impacts on the 

 3 A cation is an element ion with a positive charge (missing electrons) such as iron (Fe2+), manganese (Mn2+), 

calcium (Ca2+), potassium (K+

) and sodium (Na+). Cation Exchange Capacity is a term used to describe the ability of 

soil anions (negatively charged clay, organic matter and inorganic minerals such as phosphate, sulfate, and nitrate) 

to adsorb and store soil cation nutrients (such as potassium, calcium and ammonium).
23

chemical, physical, and biological characteristics of soil. Plant root exudates play a major role in 

the microbial community structure and resource availability in the rhizosphere (Bais et al., 2006). 

Because of the close association with bacteria, fungi, actinomycetes, and other soil microbes, 

corn roots play a key role in influencing nutrient cycling and availability necessary for plant 

growth (OECD, 2003).

Pesticide use has the potential to affect soil quality due to impacts to the microbial community, 

and is discussed further in Subsection 2.3.4, Microorganisms. Glyphosate is rapidly and tightly 

adsorbed in soil; its adsorption rate is minimally influenced by organic matter, the amount of 

clay, silt, or sand, and pH, although soil high in phosphate decreases its adsorption (Senseman, 

2007), making it more available for plant uptake, microbial degradation, and leaching (Kremer 

and Means, 2009)

4

. Glyphosate is microbially degraded in soil and water and the rate of 

decomposition varies with the microbial structure and population, having an average soil residual 

half-life of 47 days (Senseman, 2007). It has been reported that glyphosate appears to interact 

with manganese by forming insoluble, stable complexes that either immobilize this element, 

reducing plant uptake, or preventing reduction in the plant, making it unavailable (Eker et al., 

2006; Neumann et al., 2006; Ozturk et al., 2008; Cakmak et al., 2009; Huber, 2010). Huber 

(2010) and Cakmak (2009) also reported that glyphosate is a broad-spectrum chelate of several 

other nutrients (e.g., iron, calcium, magnesium, copper, iron, nickel, and zinc); however, these 

assertions are not without debate. Hartzler (2010) agrees that glyphosate could immobilize 

essential elements temporarily, but offers that it does not specifically target manganese or any 

other particular element, but instead targets those cations that are most prevalent in the soil. 

Hartzler (2010) also reports that areas in which glyphosate interactions with manganese nutrition 

are reported are also areas with known soil manganese deficiencies. Camberato (2010) points 

out that manganese deficiency is not a new phenomenon and is also associated with high pH, low 

moisture, or high levels of organic matter; furthermore, manganese deficiency is easily 

recognizable and can usually be resolved through foliar application(s) of manganese fertilizers. 

2.2.2 Water Resources

The principal law governing pollution of the nation’s water resources is the Federal Water 

Pollution Control Act of 1972, better known as the Clean Water Act (CWA). The Act utilizes 

water quality standards, permitting requirements, and monitoring to protect water quality. The 

EPA sets the standards for water pollution abatement for all waters of the U.S. under the 

programs contained in the CWA, but, in most cases, gives qualified States the authority to issue 

and enforce permits. Drinking water is protected under the Safe Drinking Water Act (SDWA) of 

1974 (Public Law 93-523, 42 U.S.C. 300 et seq.). 

Surface water in rivers, streams, creeks, lakes, and reservoirs supports everyday life by providing 

water for drinking and other public uses, irrigation, and industry (USGS, 2011). In 2005, about 

77% of the freshwater used in the U.S. came from surface-water sources, whereas the other 23% 

came from groundwater (USGS, 2011). Groundwater is the water that fills cracks and other 

openings in beds of rocks and sand (USGS, 2009). Each drop of rain that soaks into the soils 

moves downward to the water table, which is the water level in the groundwater reservoir.

 4 Adsorption is a scientific term used to describe the “adhesion” of atoms, ions, or molecules onto a surface, whereas 

absorption refers to the transfer of a substance into another substance or medium.
24

The CWA (33 U.S.C. 1251 et seq.) establishes the basic structure for regulating discharges of 

pollutants into the waters of the U.S. and regulating quality standards for surface waters. It is the 

cornerstone of surface water quality protection in the U.S.; however, it does not deal directly 

with groundwater or with water quantity issues. Surface water is an important natural resource 

used for many purposes, especially irrigation and public supply of drinking water and for 

everyday uses. The CWA employs a variety of regulatory and nonregulatory tools to sharply 

reduce direct pollutant discharges into waterways, finance municipal wastewater treatment 

facilities, and manage polluted runoff (US-EPA, 2008a). It also provides resources to help 

manage nonpoint source pollution (NPS). NPS is caused by rainfall, snowmelt, or irrigation 

moving over and through the ground that picks up and carries with it natural and human-made 

pollutants, depositing them into lakes, rivers, wetlands, coastal waters, and groundwater (USEPA, 2011f). 

The SDWA is the main Federal law that ensures the quality of U.S. drinking water. Under the 

SDWA, the EPA sets national health-based standards for drinking water quality to protect 

against both naturally-occurring and man-made contaminants that may be found in drinking 

water. The EPA also oversees the states, localities, and water suppliers who implement those 

standards (US-EPA, 2011g). The Sole Source Aquifer (SSA) designation under the SDWA is 

used to protect drinking water supplies in areas with few or no alternative groundwater 

resources, and where if contamination occurred, using an alternative source would be extremely 

expensive (US-EPA, 2011h). The EPA defines SSA as an aquifer that supplies at least 50% of 

the drinking water consumed in the area overlying the aquifer. There are 77 designated SSAs in 

the U.S. and its territories (US-EPA, 2011h) . 

Agriculture is one of the largest users of water in the U.S. Approximately 40% of the water 

withdrawn from U.S. surface and groundwater sources is used for agricultural irrigation (CAST, 

2009). Although the proportion of available freshwater used in agriculture varies widely among 

geographic areas, it is a major proportion of water use in every area. Corn requires water for 

germination, photosynthesis, cell structure and fullness, and transpiration (i.e., water movement 

to the atmosphere via movement through the growing plant) (McClaren, 2009). According to the 

National Corn Growers’ Association (NCGA) and ARMS data for corn production practices,

corn is not as water-intensive as many other crops; with only about 11 to 11.5% of corn acreage 

irrigated in 2010 (NCGA, 2011). The estimated average amount of water applied per irrigated 

acre was 10.7 inches (USDA-ERS, 2011e). The crop yield per irrigated acre in 2010 was 

estimated to be 174 bushels (USDA-ERS, 2011e) compared to the average for all corn for grain, 

which in 2010 was approximately 153 bushels per year (USDA-NASS, 2011e). The ERS

estimates did not separate corn yield by corn produced for grain versus silage. In 2008, nearly 

14 million acres of harvested corn were irrigated (USDA-NASS, 2010c). Also in 2008, the four 

Water Resources Regions that irrigated corn the most included 6.54 million acres in Region 10 

(Missouri), 1.84 million acres in Region 11 (Arkansas White-Red), 1.16 million acres in Region 

08 (Lower Mississippi), and 0.73 million acres in Region 07 (Upper Mississippi) (USDA-NASS, 

2010c). 

Agricultural NPS pollution is the primary source of pollutants discharged to rivers and lakes and 

a major contributor to groundwater contamination (US-EPA, 2005). Agricultural activities that 

cause NPS pollution include poorly located or managed animal feeding operations; overgrazing 

leading to soil erosion; plowing too often or at the wrong time; and improper, excessive, or 
25

poorly timed application of pesticides, irrigation water, and fertilizer. The pollutants that result 

from agricultural practices include sediment, nutrients, pathogens, pesticides, metals, and salts 

(US-EPA, 2005). 

Weed management is a critical component to maximize corn yields and maintain a high-quality 

harvest free of weed seeds (Smith and Scott, 2006). As discussed in Subsection 2.1.2,

Agronomic Practices, weed management strategies include using a combination of tillage 

practices, chemical herbicides, and herbicide-resistant trait breeding in crops (Dill et al., 2008). 

Tillage is an important tool for managing weeds before the planting of crops and after their 

emergence, but before full crop canopy (Givens et al., 2009). Reducing tillage and conserving 

crop residue can produce many water quality benefits, such as less sediment and chemical runoff 

entering surface water, reduced usage of pesticides, improved moisture content in soil, and 

reduced potential for flooding (Fawcett and Towery, 2002). The increased amount of plant 

residue on the soil surface serves as a physical barrier to erosion and runoff, allowing more time 

for water absorption into the soil (Locke et al., 2008). There is a strong association between the 

cultivation of herbicide-resistant crops and recent improvements in tillage reduction (Fawcett 

and Towery, 2002). Dill et al. (2008) noted for the period of 2002 to 2006, rates of conventional 

tillage slightly declined in glyphosate-resistant corn production compared to non-GE corn 

cultivation, while conservation tillage in glyphosate-resistant corn production increased slightly 

over that time frame. Use of no-till practices declined during the same period; however, the rates 

of no-till cultivation were similar between glyphosate-resistant and conventional corn production

(Dill et al., 2008).

If resistance to glyphosate occurred, farmers preferred to treat weeds with herbicide mixes or 

rotations (Foresman and Glasgow, 2008; Johnson et al., 2009). The USDA has documented that 

66% of U.S. herbicide-treated corn acreage in 2010 was treated with glyphosate isopropylamine 

salt (USDA-NASS, 2011c). Glyphosate may be applied terrestrially and in aquatic settings (USEPA, 2009b). Glyphosate has several formulations including acid and a variety of salts (USEPA, 2009b). The environmental fate of glyphosate salts is not well studied, but the EPA 

assumes glyphosate salts dissociate rapidly to form glyphosate and its counter ion (US-EPA, 

2009e). Glyphosate is highly adsorbed to most soils, although the amount of organic matter, 

clay, silt, or sand content or pH has minimal effects (Senseman, 2007). It has a typical soil 

residual half-life of 47 days (Senseman, 2007), although reported field half-lives range from 2.4 

to 160 days (US-EPA, 2009e). Because glyphosate is so tightly bound to soil, little is 

transported by rain or irrigation runoff, except as adsorbed to soil particles. 

Microbes are primarily responsible for the breakdown of glyphosate, rather than by volatilization 

or photo-degradation. The main metabolite of glyphosate microbial degradation is aminomethylphosphonic acid (AMPA) (Rueppel et al., 1977; WHO, 2005). It has also been reported that 

Pseudomonas spp. bacteria degrade glyphosate, producing the metabolites sarcosine and 

phosphates (Shinabarger and Braymer, 1986; Borggaard and Gimsing, 2008). AMPA has a 

similar half-life in water as glyphosate (Giesy et al., 2000) and is ultimately degraded into carbon 

dioxide (CO2) and ammonium (NH4

+

) (Borggaard and Gimsing, 2008). Because of its low 

mobility in soil, the potential for glyphosate leaching to groundwater is low and its potential 

movement to surface waters at high levels is considered low (US-EPA, 2009e); however, 
26

glyphosate can enter surface and subsurface waters if used in close proximity to water bodies or 

by runoff from terrestrial applications (WHO, 2005). 

In water, glyphosate adsorbs to suspended organic and mineral matter and is broken down 

primarily by microorganisms. In aerobic water, sediment glyphosate has a residual half-life of 7 

days, but in anaerobic aquatic sediment settings its residual half-life is approximately 208 days 

(US-EPA, 2009e). Surfactants may be used with glyphosate because the latter is highly soluble 

in water and will easily slide off plant surfaces (US-EPA, 2009e). 

Coupe et al. (2011) recently evaluated the fate of glyphosate and its AMPA degradate on a 

watershed scale in three Mississippi River basin watersheds and compared results to a watershed 

in France. They found from 0.06 to 0.86% of glyphosate was transported to surface water, 

although their samples frequently detected both glyphosate and AMPA (Coupe et al., 2011). 

Variability was correlated to differences in source strength, rainfall runoff, and flow route. The 

study concluded the watersheds most at risk for transport of glyphosate have high application 

rates, rainfall events resulting in overland runoff, and flow routes unfiltered by soil. Glyphosate 

has not been identified as the cause of impairment to any water bodies classified as such under 

Section 303(d) of the CWA5 (US-EPA, 2011i).

2.2.3 Air Quality 

The Clean Air Act (CAA) requires the maintenance of National Ambient Air Quality Standards 

(NAAQS). The NAAQS, developed by the EPA to protect public health, establishes limits for 

six criteria pollutants: ozone (O3), nitrogen dioxide (NO2), carbon monoxide (CO), sulfur dioxide 

(SO2), lead (Pb), and inhalable particulates (coarse particulate matter (PM) greater than 2.5 

micrometers and less than 10 micrometers in diameter (PM10) and fine particles less than 2.5 

micrometers in diameter (PM2.5)). The CAA requires states to achieve and maintain the NAAQS 

within their borders. Each state may adopt requirements stricter than those of the national 

standard and each is required by the EPA to develop a State Implementation Plan (SIP) that 

contains strategies to achieve and maintain the national standard of air quality within the state. 

Areas that violate air quality standards are designated as non-attainment areas for the relevant 

pollutants, whereas areas that comply with air quality standards are designated as attainment 

areas. Primary sources of emissions associated with crop production include exhaust from 

motorized equipment such as tractors and irrigation equipment, soil particulates from tillage and 

wind induced erosion, particulates from burning of fields, and spraying of herbicides and 

pesticides. Emissions contributing to greenhouse gases (GHG) associated with global warming 

are discussed in Subsection 2.2.4, Climate Change.

Since corn is the most widely produced feed grain in the U.S., its production practices can 

substantially impact air quality. Tillage exposes soil to wind erosion and utilizes motorized 

equipment that produces emissions. The use of herbicide-resistant crops has facilitated the 

 5 Glyphosate is classified as an organophosphorus pesticide. One waterbody, Smith Canal in the California Central 

Valley Region, has been identified as being impaired by organophorphorus pesticides, principally diazinon and 

chlorpyrifos California RWQCB, Requirement for Technical Report Pursuant to California Water Code Section 

13267 (Sacramento: California Regional Water Quality Control Board, 2007), "Specific State Causes for

Impairment That Make up the National Pesticides Causes of Impairment Group," 2011i, U.S. Environmental 

Protection Agency, October 10, 

<http://iaspub.epa.gov/tmdl_waters10/attains_nation_cy.cause_detail_303d?p_cause_group_id=885>.7.
27

adoption of conservation tillage (Towery and Werblow, 2010). According to ARMS data, in 

2010 conservation tillage ranging from no-till to reduced-till conserving about 22 to 65% of 

residues was utilized on 74.5% of planted corn acres in 2010 (USDA-ERS, 2011f). Reduced 

tillage generates fewer particulates (dust) and potentially contributes to lower rates of wind 

erosion releasing soil particulates into the air, benefitting air quality (Fawcett and Towery, 2002). 

Conservation tillage also reduces equipment emissions due to decreased usage. This is 

illustrated in Table 1 utilizing the NRCS Energy Estimator: Tillage tool (USDA-NRCS, 2011a). 

The tool estimates potential fuel savings of 2,269 gallons or 42% savings per year based upon 

producing 1,000 acres of no-till corn compared to conventional till corn in the Urbana, Illinois 

postal code6

; however, NRCS is careful to note that this estimate is only approximate, as many 

variables could affect an individual operation’s actual savings.

Table 1. Total farm diesel fuel consumption estimate (in gallons per year) for no-till 

versus conventional till corn production in the Urbana, Illinois postal code.

Estimate for 1,000 acre 

corn crop

Tillage method

conventional 

tillage mulch-till ridge-till no-till

Total fuel use 5,399 4,529 4,490 3,130

Potential fuel savings over 

conventional tillage -- 870 909 2,269

Total savings -- 16% 17% 42%

Source: (USDA-NRCS, 2011a)

Volatilization of fertilizers, herbicides, and pesticides from soil and plant surfaces also 

introduces these chemicals to the air. The USDA Agricultural Research Service (ARS) is 

conducting a long-term study to identify factors that affect pesticide levels in the Chesapeake 

Bay region airshed (USDA-ARS, 2011). This study determined that volatilization is highly 

dependent upon exposure of disturbed unconsolidated soils and variability in measured 

compound levels is correlated with temperature and wind conditions. Another ARS study of 

volatilization of certain herbicides after application to fields has found moisture in dew and soils 

in higher temperature regimes significantly increases volatilization rates (USDA-ARS, 2011). 

Glyphosate has a low vapor pressure and volatilization from soils is not considered an important 

dissipation mechanism (US-EPA, 1993b).

Pesticide and herbicide spraying introduce air quality impacts from drift and diffusion. Drift is 

defined by the EPA as “the movement of pesticide through air at the time of application or soon 

thereafter, to any site other than that intended for application” (US-EPA, 2000). Diffusion is 

gaseous transformation to the atmosphere (FOCUS, 2008). Factors affecting drift and diffusion 

include application equipment and method, weather conditions, topography, and the type of crop 

being sprayed (US-EPA, 2000). The EPA is currently evaluating new regulations for pesticide 

 6 Postal codes are used in the NRCS Energy Estimator to estimate diesel fuel use and costs in the production of key 

crops for an area.
28

drift labeling and the identification of BMPs to control such drift (US-EPA, 2009d), as well as 

identifying scientific issues surrounding field volatility of conventional pesticides (US-EPA, 

2010).

Chang et al. (2011) recently evaluated the occurrence and fate of glyphosate and its degradate 

AMPA in the atmosphere and rainfall in the Mississippi River basin. They found the frequency 

of glyphosate in the air and rain was similar to that of other commonly applied herbicides such as 

atrazine and metolachlor, but its concentration in rain was higher, primarily due to the 

widespread use of glyphosate for crop production in the region (Chang et al., 2011). AMPA in 

air was sampled at a range of <0.01 to 0.97 nanograms per cubic meter, initially lower in the 

application season and increasing as glyphosate degraded in soil to produce the metabolite; its 

incidence in rain was similar to that of glyphosate. The study also investigated the source of 

glyphosate in the air and found most occurred from spray application rather than volatilization or 

transport from windborne soil. Chang et al. (2011) conclude up to 97% of glyphosate may be 

removed from the atmosphere by weekly rainfall greater than 30 millimeters (1.18 inches). 

2.2.4 Climate Change

Climate change represents a significant and lasting statistical change in climate conditions that 

may be measured across both time and space. As scientists and the public became more 

concerned with climate change and the impact that human-derived air pollutants were having on 

global temperature, the EPA identified CO2, methane (CH4), and nitrous oxide (N2O) as the key 

GHG affecting warming temperatures. While each of these gases occurs naturally in the 

atmosphere, human activity has significantly increased the concentration of these gases since the 

beginning of the industrial revolution. The level of human-produced gases accelerated even 

more so after the end of the Second World War, when industrial and consumer consumption 

flourished. With the advent of the industrial age, there has been a 36% increase in the 

concentration of CO2, 148% in CH4, and 18% in N2O (US-EPA, 2011c).

U.S. agriculture may influence climate change through various facets of the production process 

(Horowitz and Gottlieb, 2010) and conversion of land to agriculture. The major sources of GHG 

emissions associated with crop production are soil N2O emissions, soil CO2 and CH4 fluxes, and 

CO2 emissions associated with agricultural inputs and farm equipment operation (Adler et al., 

2007; US-EPA, 2011c). Over the 20-year period of 1990 to 2009, total emissions in the 

agriculture sector grew by 9.3%, and in 2009, this sector was responsible for 6.3% of total U.S. 

GHG emissions (US-EPA, 2011c). CH4 and N2O were the primary GHG emitted by agricultural 

activities. Emissions from intestinal (enteric) fermentation and manure management represent 

about 20% and 7% of total CH4 emissions from anthropogenic activities, respectively (US-EPA, 

2011c). Agricultural soil management activities including fertilizer application and cropping 

practices were the largest source of N2O emissions, accounting for 69% of all U.S. N2O 

emissions (US-EPA, 2011c). 

Agricultural practices that produce CO2 emissions include liming and the application of urea 

fertilization to agricultural soils. In 2009, the use of lime and urea fertilizers resulted in an 

increase of 9.9% of CO2 relative to 1990 emissions, mostly attributable to increased urea 

applications (US-EPA, 2011c). The agricultural sector is also responsible for CO2 emissions 

from fossil fuel combustion by farm equipment such as tractors as discussed in Subsection 2.2.3, 

Air Quality. In addition, soil disturbing practices such as tillage can result in the release of soil 
29

organic carbon (SOC), which occurs in the bodies of microorganisms (i.e., fungi, bacteria, etc.), 

in non-living organic matter, and attached to inorganic minerals in the soil. 

From 1991 to 2010, harvested corn acreage increased from approximately 75 million acres to

over 87 million acres (USDA-NASS, 2011e), and as of 2011, approximately 72% of all corn 

planted in the U.S. were GE herbicide-resistant varieties (USDA-ERS, 2011a). As discussed in 

Subsection 2.2.1, Soil Quality, the introduction of herbicide-resistant crop varieties may be 

correlated to the increase in usage of no-till or conservation tillage agriculture (Fawcett and 

Towery, 2002; Givens et al., 2009). In 1990, prior to the introduction of herbicide-resistant corn 

varieties, approximately 8% of corn acreage in the U.S. was treated using the no-till systems and 

43% was treated using conventional tillage practices (CTIC, 2011); whereas, in 2008, no-till 

systems increased to nearly 21% and conventional tillage decreased to about 35% of U.S. corn 

production acreage (CTIC, 2011). While some conserving tillage practices (i.e., ridge till and 

mulch till) decreased about 1% and 3% respectively from 1990 to 2008 and reduced tillage rates 

remained relatively constant at 24% over the same period, overall soil conserving tillage 

practices increased from about 57% in 1990 to 65% in 2008 (CTIC, 2011). Increased 

conservation tillage operations reduce GHG emissions directly through reductions in fossil fuel 

consumption and accumulation of crop residue (Brookes and Barfoot, 2006). The relative 

contribution of conservation tillage to carbon sequestration in soil is variable, dependent upon 

soil and climate characteristics (Lal, 2004), as well as cropping systems and the amount of crop 

residue generated; further, under certain conditions, full inversion tillage may sequester carbon at 

similar rates as conservation tillage, only at a greater depth in the soil profile (Angers and 

Ericksen-Hamel, 2008; Varvel and Wilhelm, 2011). 

The impacts of herbicide-resistant crop varieties on climate change are dependent on many 

variables including cropping systems, production practices, geographic distribution of activities, 

and individual grower decisions. Agricultural practices produce emissions that may contribute to 

climate change, and impacts from climate change potentially impact agriculture. Field et al. 

(2007) reports that most studies project likely climate-related yield increases of 5 to 20% for 

corn, rice, sorghum, soybean, wheat, common forages, cotton, some fruits, and irrigated grains; 

however, they go on to report that positive impacts would not be observed evenly across all 

regions, as certain areas of the U.S. that are currently near climate thresholds are expected to be 

negatively impacted by such impacts as substantially reduced water resources. In addition, the 

current range of weeds and pests of agriculture is expected to change in response to climate 

change (USGCRP, 2009).

2.3 Biological Resources

This section provides a summary of the biological environment and includes an overview of 

animals, plants, gene transfer, weeds and weediness, microorganisms, and biodiversity. This 

summary provides the foundation to assess the potential impact to plant and animal communities, 

and the potential for gene movement. 

2.3.1 Animal Communities

Animal communities in this discussion include wildlife species and their habitats. Wildlife refers 

to both native and introduced species of mammals, birds, amphibians, reptiles, invertebrates, and 

fish/shellfish. Wildlife species use a wide range of strategies to meet their needs from highly 
30

adaptable generalists to specialists that require a narrow set of conditions to survive (Bolen and 

Robinson, 2003). Wildlife may also occupy a wide array of habitats, including agricultural 

lands. Agriculture dominates human uses of land (Robertson and Swinton, 2005). In 2010, 920 

million acres (47%) of the contiguous 48 states were devoted to farming, including: crop 

production, pasture, rangeland, Conservation Reserve Program, Wetlands Reserve Program, or 

other government program uses (USDA-NASS, 2011g). How these lands are maintained 

influences the function and integrity of ecosystems and the wildlife populations that they 

support. 

For the purposes of this analysis, discussion is limited to vertebrates and invertebrates that feed 

on corn and live in and adjacent to cornfields. Corn is commercially produced in all continental 

U.S. states except for Alaska and is grown in winter nurseries in Hawaii and the Puerto Rico 

territory (Leidy, 2009; Alfaro, 2011). As a result, a wide array of wildlife species occupy 

habitats that are within or adjacent to cornfields, although few species directly utilize corn for 

food or shelter. Corn is, however, a nutrient-rich source for many waterfowl species for fat 

synthesis prior to migration (Krapu et al., 2004). Additionally, during the spring, summer, and 

fall months, cornfields provide browse for rabbits (Sylvilagus floridana); deer (Odocoileus 

virginianus); bears (Ursidae); squirrels (Sciurus spp., Spermophilus tridecemlineatus); raccoons 

(Procyon lotor); a variety of rodents and small mammals; wild turkey (Meleagris gallopavo); 

pheasants (Phasianus colchicus); quail (Colinus virginianus); and some songbirds while also 

providing a forage base for insects (Mattson, 1990; Miller and Hazzard, 1996; Krapu et al., 2004; 

MacGowan et al., 2006; Ohio Division of Wildlife, 2011; Palmer et al., 2011). Cornfields also 

attract species that prey on those animals directly using the field as a food source or habitat, such 

as predatory birds and insects feeding on other insects that infest corn (Quiring and Timmons, 

1987; Clark et al., 1994; Tremblay et al., 2001). During the winter, waste corn provides a food

source for wildlife, and if not fall plowed or harvested for silage, cornfields provide winter cover 

(Ohio Division of Wildlife, 2011; Palmer et al., 2011). 

Cornfields are intensively cultivated lands that provide less suitable habitat for wildlife than 

adjacent pasture, fallow fields, or windbreaks and shelterbelts. As discussed in Subsection 2.1.2, 

Agronomic Practices, no-till corn production that may provide better habitat for some wildlife is 

practiced in the U.S., but not extensively, with only approximately 24% of planted corn produced 

under the no-till system (USDA-ERS, 2011f). Conservation tillage practices can benefit wildlife 

through improved water quality, availability of waste grain, retention of cover in fields, and 

increased populations of invertebrates (Brady, 2007; Sharpe, 2010). Conservation tillage 

practices that leave greater amounts of crop residue increase the diversity and density of birds 

and mammals (USDA-NRCS, 1999a). Increased residue also provides habitat for insects and 

other arthropods, consequently increasing this food source for insect predators. Insects are 

important during the spring and summer brood rearing season for many upland game birds and 

other birds, as they provide a protein-rich diet to fast growing young, as well as a nutrient-rich 

diet for migratory birds (USDA-NRCS, 2003).

Insects such as the lady beetle (Coccinellidae), big-eyed bug (Lygaeidae), ground beetle 

(Carabidae), lacewing (Chrysopidae), damsel bug (Nabidae), insidious flower bug/minute pirate 

bug (Anthocoridae), assassin bug (Triatominae), spined soldier bug (Pentatomidae), and 

parasitoid wasps (e.g., Braconidae, Ichneumonidae), as well as a multitude of spiders (Order: 

Araneae) may benefit corn production by preying on plant pests (Stewart et al., 2007; Iowa State 
31

University, No Date). Other, soil dwelling fauna such as earthworms and arthropods play critical 

roles in the aeration and turn-over of soil, processing of wastes and detritus, and nutrient cycling 

(ATTRA, 1999; USDA-NRCS, 2004). Conversely, there are many insects and invertebrates that 

are detrimental to corn crops, such as the corn earworm (Helicoverpa zea), corn rootworm 

(Diabrotica spp.), and European corn borer (Ostrina nubilalis) (University of Illinois, 2003; 

University of Illinois, 2004a; University of Illinois, 2004b). 

Herbicide use for the control of weeds in corn production has the potential to affect wildlife. The 

environmental effects associated with glyphosate use are summarized in the most recent 

Glyphosate Reregistration Eligibility Decision (RED) Facts (US-EPA, 1993a). Since 2009, 

glyphosate has been under review by the EPA for continued registration of the herbicide, with a 

reregistration decision expected in 2015 (US-EPA, 2009a). Assessments of the toxicity of 

glyphosate to animal species indicate registered uses pose a minimal risk to animals, but the 

herbicide may cause adverse effects to plants providing animal habitat. Glyphosate is 

moderately toxic to mammals, no more than slightly toxic to birds, and practically nontoxic to 

fish, aquatic invertebrates, and honeybees (US-EPA, 1993a). Non-target exposure for animal 

habitats typically results from runoff or spray drift (US-EPA, 1993b). EPA-approved labels 

governing use that includes measures such as appropriate droplet size settings and assessment of 

wind, weather, and temperature inversion conditions (Monsanto, 2010). The EPA is also 

currently evaluating new regulations for pesticide drift labeling and the identification of BMPs to 

control such drift (US-EPA, 2009d), as well as identifying scientific issues surrounding field 

volatility of conventional pesticides (US-EPA, 2010). While animals can also be affected from 

runoff and drift, ingestion is often the primary cause of exposure. The final work plan for the 

reregistration review of glyphosate has identified additional data needs concerning potential 

impacts to terrestrial animals and certain aquatic species (US-EPA, 2009a). Part of the EPA 

reregistration assessment will include an acute avian oral toxicity study for passerine species. 

The glyphosate degradate, AMPA, has not been fully evaluated for ecological risk, which will be 

undertaken in the current EPA review (US-EPA, 2009a). Additionally, some inert ingredients 

used as surfactants applied with glyphosate that increase its absorption are more toxic than 

glyphosate to aquatic organisms, and will be evaluated for acute toxicity to estuarine and marine 

mollusks, invertebrates, and fish (US-EPA, 2009a). 

2.3.2 Plants Communities

Corn production in the U.S. encompasses a wide range of physiographic regions, ecosystems, 

and climatic zones since it is grown in every U.S. state except Alaska (USDA-NASS, 2011b; 

USDA-NASS, 2011h). Plants communities are varied and adapted to local climate and soil, as 

well as the frequency of natural or human-induced disturbance (Smith and Smith, 2003). Noncrop vegetation in cornfields is limited by cultivation and weed control practices used by 

producers. Plants communities adjacent to cornfields may be other crops, pasturelands, 

rangelands, grasslands, forest, or conservation covers designed to control soil erosion and wind. 

Areas adjacent to cornfields are often highly managed to minimize sources of weed and insect 

invasion, and reduce cover or perches from which other pests may easily feed on the crop (Pierce 

II et al., 2008). 

Weeds are simply plants growing in areas undesired by humans (Baucom and Holt, 2009). 

Weeds are the most important pest complex in agriculture and are represented by plants with 
32

specific characteristics that make these species uniquely adapted to agriculture (Gibson et al., 

2005; Baucom and Holt, 2009). Plants that colonize frequently disturbed environments exhibit 

early germination and rapid growth from seedling to sexual maturity, have the ability to 

reproduce sexually and asexually and are well-adapted to agricultural fields (Baucom and Holt, 

2009). Weeds compete with crops for light, nutrients, and water, and therefore, have the 

potential to significantly affect yields. Their ability to compete with crops depends on the 

specific weed (e.g., woolly cupgrass (Eriochloa villosa) is more competitive than giant foxtail

(Setaria faberi)), population density, the diversity of the weed community, and the length of time 

the weed community has been established in the crop field (Bosnic and Swanton, 1997; Fausey 

et al., 1997; Owen, 1999). Types of weeds encountered in corn production vary by region, but 

common weeds include common waterhemp (Amaranthus rudis), giant ragweed (Ambrosia 

trifida), common lambsquarters (Chenopodium alum), velvetleaf (Abutilon theophrasti), giant 

foxtail, and horseweed (Conyza canadensis) (Moore, 2012).

Loss of corn yield attributable to weeds varies. Smith and Scott (2006) estimate that light 

infestation may reduce yields 10 to 15%, and heavier infestations potentially reducing yields up 

to 50%. Bosnic and Swanton (1997) report a 26 to 35% loss from early emerging barnyardgrass, 

yet this loss drops to less than 6% from barnyardgrass emergence after corn has reached the fourleaf growth stage. Johnson et al. (2007) found that corn yield was not reduced by early season 

giant ragweed, yet yield dropped by 19% from season-long interference. Yield reductions

depend on weed prevalence at critical growth stages (Halford et al., 2001; Knezevic et al., 2002). 

Generally, weeds must be controlled early in the development of corn in order to protect 

potential corn yields (Smith and Scott, 2006).

Collectively, the practices used in crop production will ultimately impart selection pressures 

upon the weed community, resulting in shifts in the relative importance of specific weeds. 

Agricultural practices with the most impact on weed composition and prevalence are tillage and 

herbicide regime (Owen, 2008). Weed shifts are illustrated by a previously unimportant weed 

achieving ecological dominance due to changes in production practices (e.g., Asiatic dayflower) 

or the evolution of an herbicide-resistant weed biotype due to herbicide-use practices (e.g.,

common waterhemp) (Owen, 2008; Ulloa and Owen, 2009). In aggressive tillage systems, weed 

diversity tends to decline and annual grasses and broadleaf plants are the dominant weeds, 

whereas, in no-till fields, greater diversity of annual and perennial weed species may occur 

(Baucom and Holt, 2009). 

As described in Subsection 2.1.2, Agronomic Practices, while there are numerous tactics that 

will provide weed management, herbicides have been the dominant approach in corn production 

(Gianessi and Reigner, 2007; Green and Owen, 2011). Herbicide resistance naturally evolves 

when a plant survives and reproduces after exposure to a dose of herbicide usually lethal to the 

wild type, passing this ability down to its future generations (WSSA, 2008). With repeated use 

of the herbicide, the herbicide-resistant plants can quickly reproduce and spread to dominate the 

plant (weed) population and seed bank (WSSA, 2011).

Currently, there are 370 herbicide-resistant weed biotypes that have been reported representing 

200 species and infesting an estimated 570,000 fields globally (Heap, 2011). Weeds with 

evolved resistance to glyphosate have increased since the commercial introduction of the 

Roundup Ready® glyphosate-resistant crops in 1996 (Heap, 2011; Owen et al., 2011). It should 
33

be noted, however, that the GE crop in this case, namely corn, did not directly cause the 

resistance to evolve as a result of introgression; there are no near-relative weeds that are 

compatible with corn (Ellstrand et al., 1999). As of December 2011, there are 21 weed species 

with evolved resistance to glyphosate world-wide and 13 in the U.S. (Table 2) (Heap, 2011; 

Owen et al., 2011). In the U.S., it is estimated that 11 of the 13 glyphosate-resistant weed 

species were identified in glyphosate-resistant crop systems and are widely distributed in regions 

where agriculture predominates. For example, 15 states have from 2 to 7 weed species with 

evolved resistance to glyphosate (Table 3) (Heap, 2011). Table 3 illustrates how widespread 

herbicide-resistant weeds are in the U.S., as the same 15 states with glyphosate-resistant weeds 

have also identified at least 1 weed species with resistance to 3 to 8 herbicide modes of action. 

Table 2. U.S. glyphosate-resistant weeds as of December 2011.

System Species Year Identified

Weeds identified outside of 

Roundup Ready® Systems

Rigid Ryegrass (Lolium rigidum) 1998

Hairy Fleabane (Conyza bonariensis) 2003

Weeds identified in Roundup 

Ready® Systems

Annual Bluegrass (Poa annua) 2010

Common Ragweed (Ambrosia 

artemisiifolia)

2004

Common Waterhemp (Amaranthus 

rudis)

2005

Giant Ragweed (Ambrosia trifida) 2004

Goosesgrass (Eleusene indica) 2010

Horseweed, Marestail (Conyza 

canadensis)

2000

Italian Ryegrass (Lolium multiflorum) 2001

Johnsongrass (Sorghum halepense) 2005

Junglerice (Echinochloa colona) 2008

Kochia (Kochia scoparia) 2007

Palmer Amaranth (Amaranthus palmeri) 2005

Source: (Heap, 2011)

Many of the glyphosate-resistant weeds are agronomically important and dominant members of 

weed communities. For example, glyphosate-resistant Palmer pigweed (amaranth) is a major 

economic problem in the Southeast U.S., while glyphosate-resistant waterhemp is an 

economically important weed in Midwestern states (Culpepper et al., 2006; Owen, 2008). Other 

glyphosate-resistant weeds of importance include giant ragweed, common lambsquarters, and 

horseweed (Owen, 2008; Owen et al., 2011). 

As described in Subsection 2.1.2, Agronomic Practices, the most effective weed management 

programs focus on the inclusion of diverse control tactics in addition to herbicides (Beckie, 

2006; Owen, 2011; Owen et al., 2011). Given that many weeds have evolved multiple 

resistances to several herbicide mechanisms of action, it is important that herbicide diversity of 

mechanisms of action also be a factor in herbicide selection. The key consideration to managing 

herbicide-resistant weeds is to ensure that the herbicides used continue to have efficacy on the 

target weeds. Managing weed species that have evolved multiple resistances can be challenging. 
34

In corn production where sufficient herbicide mechanisms of action typically are available, 

Beckie and Reboud (2009) recommend the use of herbicides in tank mixtures rather than to

simply rotate herbicide modes of action. However, in a study of the efficacy of acetolactate 

synthase (ALS)-inhibitor mixtures, Wrubel and Gressel (1994) note that not all mixtures meet all 

the criteria for resistance management, and the use of mixtures for short-term economic benefit 

risks increasing widespread resistance to herbicides. Weed scientists recommend the use of an 

integrated systems approach of including science-based crop improvement and farm 

management tools developed over the last 60 years, and providing producers reasonable and 

attractive alternatives for effective weed management (Gunsolus, 2002; Beckie, 2006; Owen et 

al., 2011; Sellers et al., 2011).

Table 3. U.S. states with more than one weed species with glyphosate resistance.

State Number of weed 

species with glyphosate 

resistance

Number of herbicide 

modes of action with at 

least one resistant weed 

species

Arkansas 6 8

California 4 8

Illinois 3 5

Indiana 4 3

Iowa 3 6

Kansas 5 5

Louisiana 2 5

Michigan 2 5

Minnesota 3 4

Mississippi 7 7

Missouri 6 5

North Carolina 2 6

Ohio 3 5

Tennessee 4 6

Virginia 2 4

Source: (Heap, 2011)

Corn seeds that overwinter and germinate in subsequent crops are “volunteers” and are also 

considered weeds. Domesticated corn needs human intervention to disperse its seeds, as they are 

tightly bound to the cob and protected within husks (OECD, 2003). Harvesting and transporting 

corn from the field can release individual kernels that survive and germinate the following year, 

but corn is incapable of sustained reproduction outside of agriculture (OECD, 2003); thus, has 

little potential to become a weed outside of cultivated fields (see Subsection 2.3.3, Gene Flow 

and Weediness, for an in depth discussion of feral corn weediness). 

Volunteer corn frequently occurs in soybean, cotton, and other crops such as sugar beets, other 

dry beans, and the following year’s corn crop (Bernards et al., 2010; Monsanto, No Date; Wilson 

et al., No Date). Volunteer corn can be quite extensive in fields, competing with the desired crop 

for light, nutrients, and moisture (Wilson et al., No Date) and is particularly problematic with 

short crops such as soybeans and sugar beets. As a result of transgene pollen movement, some 
35

volunteer glyphosate-resistant corn plants occur in fields even if glyphosate-resistant corn was 

not planted the previous year (Beckie and Owen, 2007). While pollen mediated gene transfer 

can occur in corn, as discussed in Subsection 2.3.3, Gene Flow and Weediness, gene flow in the 

crop decreases rapidly with separation distance. Controlling volunteer corn early is the key to 

preserving yields in these desired crops. Prevention of volunteer corn is achievable by selecting 

cultivars with adequate stalk strength and ear retention qualities; minimizing disease and insect 

infestations that result in pre-harvest ear losses; harvesting corn on time and with equipment 

having correct settings; and, operating harvest equipment at appropriate speeds (Beckie and 

Owen, 2007; Bernards et al., 2010; Monsanto, No Date). Management could also be 

accomplished by applying post-emergence grass herbicides in subsequent broadleaf crops, 

planting a corn variety resistant to a different mode of action than the previous corn crop, or 

performing spring tillage (Wilson et al., No Date).

Volunteer corn may be managed and crop damage minimized by early and diligent scouting, 

mechanical inter-row cultivation or flame weeding, and the application of herbicides. The most 

effective herbicides for eliminating volunteer corn are those with efficacy in grasses (i.e.,

graminicides), including glyphosate application to conventional corn volunteers in glyphosateresistant corn. Controlling glyphosate-resistant corn in subsequent glyphosate-resistant broadleaf crops such as soybean may be achieved by application of acetyl-CoA synthase (ACCase)-

inhibitors and ALS herbicides such as Assure II®, Fusilade®, Select®, Poast®, Raptor®, and 

Wolverine® (Hager, 2007; Zollinger et al., 2011). The use of paraquat or an ALS inhibitor such 

as Finesse® is effective for controlling glyphosate-resistant corn in wheat (Martin, 2010). 

Controlling volunteer glyphosate-resistant corn in cornfields may be achieved by alternating the 

glyphosate-resistant corn with non-GE corn or with GE corn cultivars having resistance to 

herbicides with different modes of action, and then application of that herbicide post-emergence, 

such as LibertyLink® and glufosinate (Beckie and Owen, 2007; Wilson et al., No Date). Beckie 

and Owen (2007) suggest that the most effective method of controlling volunteer crops is to

utilize a combination of these techniques.

The application of an herbicide in corn production has the potential to impact non-target plants 

communities through spray drift, volatilization (evaporation), its adsorption to soils incorporated 

in runoff, leaching, and cleaning and disposal of the equipment used to dispense it. Factors 

affecting drift and diffusion include application equipment and method, weather conditions, 

topography, and the type of crop being sprayed (US-EPA, 2000). The EPA is currently 

evaluating new regulations for pesticide drift labeling and the identification of BMPs to control 

such drift (US-EPA, 2009d), as well as identifying scientific issues surrounding field volatility of 

conventional pesticides (US-EPA, 2010).

The environmental effects associated with glyphosate use are summarized in the most recent 

Glyphosate RED Facts (US-EPA, 1993a). As mentioned previously, glyphosate is currently 

under review by EPA for continued registration of the herbicide, with a reregistration decision 

expected in 2015 (US-EPA, 2009a). Glyphosate is toxic to most terrestrial and aquatic plants, 

inducing plant death. The leaching potential of glyphosate is minimal as it tightly adsorbs to soil 

particles (Senseman, 2007). It also has a low vapor pressure and volatility from soils (US-EPA, 

1993b). In its 1993 glyphosate reregistration decision, the EPA required additional studies 

concerning vegetative vigor, droplet size spectrum, and a drift field evaluation that did not affect 

the reregistration eligibility of the herbicide (US-EPA, 1993a). EPA-approved labels provide 
36

detailed measures to manage spray drift including optimal wind conditions, temperature 

inversions, humidity, spray droplet size, sprayer boom heights, aerial spraying by aircraft 

measures, and inclusion of drift reduction additives (Monsanto, 2010). 

2.3.3 Gene Flow and Weediness

Gene flow is a biological process that facilitates the production of hybrid plants, introgression of 

novel alleles (i.e., versions of a gene) into a population, and evolution of new plant genotypes. 

Gene flow to and from an agro-ecosystem can occur on both spatial and temporal scales. In 

general, plant pollen tends to represent the major reproductive method for moving across space, 

while both seed and vegetative propagation tend to promote the movement of genes across time 

and space. 

The rate and success of gene flow is dependent on numerous external factors in addition to the 

intrinsic reproductive biology of donor/recipient plants (Chandler and Dunwell, 2008; Zapiola et 

al., 2008). External factors important to pollen-mediated gene flow include the presence/

abundance/distance of sexually-compatible plant species; overlap of flowering phenology 

between populations; wind versus insect pollination; the amount and duration of pollen 

production; and weather conditions such as temperature, wind, and humidity. Seed-mediated 

gene flow also depends on many factors, including the absence/presence/magnitude of seed 

dormancy, contribution and participation in various dispersal pathways, and environmental 

conditions and events. 

Corn plants do not produce clonal structures (shoots) that then develop into plants (vegetative 

propagules); therefore, asexual reproduction and gene flow as a result of dispersal of vegetative 

tissues does not occur with corn. Corn is self-compatible and primarily pollinated by wind or 

gravity with minimal contribution from insect pollination (McGregor, 1976; Thomison, 2009). 

There are no extant populations of sexually compatible species related to Z. mays within the 

continental U.S., its territories, or possessions; therefore, APHIS (2011b) has concluded that 

there is not a significant risk of gene movement between corn and its wild or weedy maize 

relatives. 

Molecular evidence of gene flow among corn, Z. mexicana and Z. mays ssp. parviglumis, has 

been documented to occur at low frequencies among extant populations of these species in 

Mexico and likely due to historical admixture among native populations in the same geographic 

area rather than recent introgression (Ross-Ibarra et al., 2009). Complex mechanisms of 

incompatibility have been described that are barriers to gene flow (Kermicle and Evans, 2010). 

While corn and various teosinte species are culturally and biologically similar, and gene 

exchange between these groups has been documented, no successful weedy species has evolved 

(US-EPA, 2011b).

Pollen-mediated Gene Flow and Mitigation

Many varieties of corn are cultivated in the U.S. For gene flow to occur between corn varieties, 

flowering of the source and sink populations must overlap, pollen transfer must occur, embryo/

seeds must develop, and hybrid seed must disperse and establish. Corn is a monoecious (having 

both male and female reproductive units), out-crossing, wind-pollinated crop that produces 

abundant, large, and heavy pollen. The reproductive morphology of corn encourages cross-
37

pollination between corn plants and there is no evidence (genetic or biological barriers) to 

indicate that gene flow is restricted between genetically modified, conventional, and organic 

corn.

A number of studies have investigated pollen dispersal, cross-fertilization, and gene flow 

involving corn grain production fields. Sanvido et al. (2008) reviewed these studies and found 

that pollen-mediated gene flow typically decreases to less than 0.5% beyond 50 meters 

(approximately 164 feet) and proposes this as an adequate isolation distance for GE cornfields in 

areas with dense corn production. In comparisons of outcrossing relating to both distance and 

temporal separation in California and Washington, Halsey et al. (2005), found that temporal 

separation reduced the occurrence of outcrossing, yet the difference was only statistically 

significant in California due to the rate of crop growth. At both study locations, 200 meters 

(approximately 656 feet) was found to reduce outcrossing to <0.1%. Spatial and temporal 

isolation can be one of the most effective barriers to gene exchange between corn crop cultivars. 

Current practices for maintaining the purity of hybrid seed production in corn are typically 

successful for maintaining 99% genetic purity, though higher instances of out-crossing can occur 

(Ireland et al., 2006). Requirements and methods to ensure seed and crop purity are discussed in 

more detail in Subsections 2.1.3, Corn Seed Production, and 2.1.4, Organic Corn Production.

Seed-mediated Gene Flow and Mitigation

For gene flow to occur via seeds and result in feral populations of corn, seeds must disperse and 

establish in new habitats. Generally, gene flow by seed is dependent on natural dispersal 

mechanisms, such as water, wind, animals, or by human actions and is favored by characteristics 

such as small and lightweight seed size, prolific production, seed longevity and dormancy, and 

long distance seed transport (Mallory-Smith and Zapiola, 2008). Corn does not possess the 

characteristics for efficient seed-mediated gene flow. Through thousands of years of selective 

breeding by humans, corn has been extensively modified to depend on human cultivation for 

survival (Doebley, 2004). As a result of its domestication, corn is not able to survive in the wild,

and also has several traits that greatly reduce its ability to disperse via seeds (OECD, 2003). 

Humans have selected corn to produce seeds that do not shatter and cannot disperse from the 

cob, and corn seeds are tightly bound within a protective sheath of leaves or husk (Doebley, 

2004). Corn seeds lack dormancy and will not produce a persistent seed bank; additionally, corn 

seeds are large and heavy and not easily dispersed by wind or water (Mallory-Smith and Zapiola, 

2008). Any crop seeds that remain on the field after harvest and are viable to germinate the 

following year in rotation crops are termed volunteers (Carpenter et al., 2002) and considered 

weeds since they are out of place (see Subsection 2.3.2, Plants Communities, for a more detailed 

discussion on volunteer corn). Fortunately, volunteer corn in subsequent crops is relatively 

easily managed by a combination of agronomic practices and mechanical means, and the 

application of herbicides.

Global dispersal of seed leading to adventitious presence in seed or grain stocks has been 

documented (Marvier and Van Acker, 2005; Mercer and Wainwright, 2008; Dyer et al., 2009; 

Piñeyro-Nelson et al., 2009; Gamarra et al., 2011). Its presence can be mitigated by effective 

quality control analysis of seed prior to sale, coupled with best practices of product stewardship 

by seed companies and growers. Moreover, compliance with identity preservation protocols 
38

outlined by organizations such as AOSCA (2003) would minimize the potential for inadvertent 

inclusion of GE crops. 

Horizontal Gene Flow

The potential for horizontal gene flow from a plant species to bacteria or fungi is unlikely to 

occur (Keese, 2008). There are several bacteria and fungi associated with plants such as 

commensals, symbionts, parasites, pathogens, decomposers, and those found in herbivore guts; 

however, there are very few evolutionary examples of horizontal gene transfer from plants to 

bacteria or fungi (Keese, 2008). Many bacteria (or parts thereof) that are closely associated with 

plants have been sequenced including Agrobacterium and Rhizobium (Kaneko et al., 2000; Wood 

et al., 2001; Kaneko et al., 2002). There is no evidence that these organisms contain genes 

derived from plants. In cases where the review of sequence data implied that horizontal gene 

transfer occurred, these events were inferred to occur on an evolutionary time scale in the order 

of millions of years (Koonin et al., 2001; Brown, 2003). The FDA has also evaluated horizontal 

gene transfer from the use of antibiotic resistance marker genes, and concluded that the 

likelihood of transfer of antibiotic resistance genes from plant genomes to microorganisms in the 

gastrointestinal tract of humans or animals or in the environment is remote (US-FDA, 1998b). 

The probability of gene flow from corn to other organisms is, therefore, considered to be 

unlikely.

2.3.4 Microorganisms

Soil microorganisms play a key role in soil structure formation, decomposition of organic matter, 

toxin removal, nutrient cycling, and most biochemical soil processes (Garbeva et al., 2004). 

They also suppress soil-borne plant diseases and promote plant growth (Doran et al., 1996). The 

main factors affecting microbial population size and diversity include soil type (texture, 

structure, organic matter, aggregate stability, pH, and nutrient content), plant type (providers of 

specific carbon and energy sources into the soil), and agricultural management practices (crop 

rotation, tillage, herbicide and fertilizer application, and irrigation) (Garbeva et al., 2004). Plant 

roots, including those of corn, release a variety of compounds into the soil creating a unique 

environment for microorganisms in the rhizosphere. Microbial diversity in the rhizosphere may 

be extensive and differs from the microbial community in the bulk soil (Garbeva et al., 2004). 

The structure of soil microbial communities is highly dependent on plant type, the physical and 

chemical characteristics of the soil, and climate (Garbeva et al., 2004; Marschner et al., 2004; 

Gupta et al., 2007). As such, potential changes to the soil microbial community as a result of 

cultivating genetically modified crops has been of research interest (O'Callaghan and Glare, 

2001; Kowalchuk et al., 2003; Dunfield and Germida, 2004). There are potential direct and 

indirect impacts from the large-scale use of GE crops to soil- and plant-associated microbial 

communities, both in the rhizosphere and bulk soil (Lynch et al., 2004; Motavalli et al., 2004). 

Direct impacts include changes to the structural and functional community near the roots due to 

altered root exudation or the transfer of GE material, or a change in microbial populations due to 

the changes in agronomic practices used to produce GE crops (e.g., use of agricultural chemicals 

and fertilizers and tillage). Indirect impacts may arise from changes in the amount and 

composition of residue from the GE crops. 
39

Studies to determine the impact of GE crops on soil microbial communities are mixed. A review 

of those investigating the impact of transgenic plants on microbial soil communities completed 

by Kowalchuk et al. (2003) found that much of the research examining distinctive microbial 

traits concluded there were minor or no non-target effects; only a few found induced targeted 

alterations to the composition of the microbial community that usually resulted in the inhibition 

of plant pathogenic organisms. A similar review by Motavalli et al. (2004) did not find any 

conclusive evidence that released transgenic plants were causing significant direct impacts on 

microbe-mediated soil nutrient transformations and studies of potential indirect impacts were 

lacking.

Crop rotations influence microorganisms as the chemical and nutrient composition of plants and 

their residues can promote or suppress diseases, affect levels of organic matter, and diversify

nutrient sources for soil biota (Gupta et al., 2007). Tillage systems can alter the physiological 

and chemical properties and biological composition of soils. No-till promotes retention of soil 

organic matter and concentrates soil microorganism activity at the soil surface, while increasing 

populations of both disease suppressing and disease promoting fungi, in turn increasing species 

that feed on fungi (Gupta et al., 2007). Conventional tillage distributes organisms deeper into the 

soil, while promoting bacteria and bactivorous fauna and increasing residue breakdown 

accompanied by rapid nutrient mineralization (Gupta et al., 2007). Water is one of the important 

factors influencing microbial population structure and activity in soil; thus irrigation can have a 

substantial impact. Soil moisture carries nutrients to microorganisms and supplies hydrogen and

oxygen (AgriInfo, 2011). Microbes are most active and populous in the moisture range of 20% 

to 60%, while excess moisture conditions can create a low oxygen environment beneficial to

anaerobic microflora, and too little will not support soil microbia (Stark and Firestone, 1995; 

AgriInfo, 2011).

Fertilizers may support soil microorganisms as increased crop growth can lead to increased 

residues, building soil organic matter. But fertilizers may change the relative acidity of soils that 

can be detrimental to some microorganisms, and may reduce the beneficial symbiosis of some 

microorganisms with particular plant species (Gupta et al., 2007). Pesticides such as fungicides 

potentially impact fungal microbia.

In a comparison of fields planted with glyphosate-resistant and conventional corn and cotton, 

Locke et al. (2008) found that crops treated with glyphosate had subtle and dynamic differences 

in soil microbial populations when compared to non-glyphosate-resistant crops. The authors 

surmise that the decreased disturbance of the soil and increased level of residue as a result of 

reduced tillage on the glyphosate-treated crops allowed for a more diverse microbial population. 

A 10-year comparison study of GE glyphosate-resistant and non-GE corn and soybean by 

Kremer and Means (2009) found that glyphosate-resistant soybeans, even when not treated with 

glyphosate, had a lower number and mass of root nodules than that of non-GE soybean, 

indicating that root exudates from GE crops influence the rhizosphere microbial community.

Glyphosate is readily metabolized by soil microbes, yet its strong adsorption capacity to soil 

slows this function (Tu et al., 2001). The average half-life of glyphosate is 47 days, yet this rate 

varies depending on soil structure and microbial population (Senseman, 2007). The primary 

metabolite from microbial degradation is AMPA, which is further degraded to CO2 (US-EPA, 

1993a; Senseman, 2007). Results of research investigating the impact of glyphosate on the 
40

microbial community are mixed (Weaver et al., 2007). For example, Haney et al. (2002) and 

Araujo et al. (2003) report that glyphosate is mineralized by microorganisms that leads to an 

increase in their population and activity, while Busse et al. (2001) and Weaver et al. (2007)

found little evidence of changes to soil microorganism’s population and activity, and any 

declines recorded were small and not consistent throughout the season. It also has been reported 

that the use of glyphosate increases the colonization of soil-borne fungal pathogens such as 

Fusarium (Kremer and Means, 2009; Huber, 2010). Similarly, research by Camberato (2011)

found that some weeds treated with glyphosate and other herbicides had increased incidence of 

fungal infection, suggesting that some soil fungi are more able to infect a weed after it has been 

weakened by glyphosate. They point out, however, that plant pathologists have not observed 

widespread increases in plant diseases in glyphosate-resistant corn and soybean. In a review of 

recent studies investigating a potential link between the use of glyphosate and outbreaks of 

fungal disease, Powell and Swanton (2008) did not find sufficient evidence from field trials 

demonstrating whether a causative relationship exists. Additionally, they found that observed 

links may be context dependent, as they were found only under controlled laboratory conditions. 

The authors suggest that to adequately address the effect glyphosate has on fungal diseases, 

future investigations should consider additional interactive factors, such as inoculum level, weed 

abundance and community composition, fertility, cultural practices, climate, and soil properties.

2.3.5 Biodiversity

Biodiversity refers to all plants, animals, and microorganisms interacting in an ecosystem 

(Wilson, 1988). Biodiversity provides valuable genetic resources for crop improvement (Harlan, 

1975) and also provides other functions beyond food, fiber, fuel, and income. These include 

pollination, genetic introgression, biological control, nutrient recycling, competition against 

natural enemies, soil structure, soil and water conservation, disease suppression, control of local 

microclimate, control of local hydrological processes, and detoxification of noxious chemicals 

(Altieri, 1999). The loss of biodiversity results in a need for costly management practices in 

order to provide these functions to the crop (Altieri, 1999). 

The degree of biodiversity in an agroecosystem depends on four primary characteristics: (1) 

diversity of vegetation within and around the agroecosystem; (2) permanence of various crops 

within the system; (3) intensity of management; and (4) extent of isolation of the agroecosystem 

from natural vegetation (Southwood and Way, 1970). 

Agricultural land subject to intensive farming practices, such as that used in crop production, 

generally has low levels of biodiversity compared with adjacent natural areas. Tillage, seed bed 

preparation, planting of a monoculture crop, pesticide use, fertilizer use, and harvest result limit 

the diversity of plants and animals (Lovett et al., 2003). Biodiversity can be maintained or 

reintroduced into agroecosystems through the use of woodlots, fencerows, hedgerows, and 

wetlands. Agronomic practices include intercropping (the planting of two or more crops 

simultaneously to occupy the same field), agroforestry, crop rotations, cover crops, no-tillage, 

composting, green manuring (growing a crop specifically for the purpose of incorporating it into 

the soil in order to provide nutrients and organic matter), addition of organic matter (e.g., 

compost, green manure, animal manure), and hedgerows and windbreaks (Altieri, 1999).

The potential impact to biodiversity associated with agriculture, including the cultivation of GE 

crops, is the loss of diversity, which can occur at the crop, farm, and/or landscape scale (Visser, 
41

1998; Ammann, 2005; Carpenter, 2011). In this analysis, crop diversity refers to the genetic 

uniformity within crops, farm-scale diversity refers to the level of complexity of organisms 

within the boundaries of a farm, and landscape-scale diversity refers to potential changes in land 

use and the impacts of area-wide weed suppression beyond the farm boundaries (Carpenter, 

2011).

Crop Diversity

As indicated in reviews conducted by Carpenter (2011), Krishna et al. (2009), van de Wouw et 

al. (2010), and Visser (1998), it is widely accepted that genetic diversity in crops is beneficial as 

it may improve yields, pest and disease resistance, and quality in agricultural systems, and that 

greater varietal and species diversity enable growers to maintain productivity over a wide range 

of conditions. There is concern that the adoption of GE technology potentially reduces growerdemand for crop genetic diversity because breeding programs could concentrate on a smaller 

number of high value cultivars, which could reduce the availability of, and demand for, non-GE 

varieties (Krishna et al., 2009; Carpenter, 2011). The establishment of large monocultures of 

genetically homogeneous crops increases the vulnerability of crops to potentially catastrophic 

damage from pest and disease outbreaks (Garcia and Altieri, 2005), but this potential is not 

limited to GE crops. Several summary reviews of relevant research evaluating GE herbicideresistant soybeans and cotton, however, have provided evidence that the introduction of GE 

crops has not decreased crop diversity because of widespread use of the traits in multiple 

breeding programs and the technology enables the introduction of novel genes in crops 

(Ammann, 2005; Carpenter, 2011). Concern for the loss of genetic variability has led to the 

establishment of an extensive network of genebanks (van de Wouw et al., 2010). The National 

Plant Germplasm System manages an active collection of more than 14,000 accessions of corn at 

the USDA-ARS North Central Regional Plant Introduction Station at Iowa State University, 

Ames, Iowa (USDA-ARS, 2005). Managing the active collection involves acquiring, 

maintaining, evaluating, characterizing, and distributing this germplasm to researchers 

worldwide, which helps ensure a continuous reservoir of genetic diversity for future crop 

development. 

Farm-scale Diversity 

Adoption of GE technology has the potential to impact diversity at the farm scale by affecting a 

farm’s biota, including birds, wildlife, invertebrates, soil microorganisms, and weed populations. 

For example, an increase in adoption of conservation tillage practices is associated with the use 

of GE herbicide-resistant crops (Givens et al., 2009). Less tillage provides more wildlife habitat 

by allowing other plants to establish between crop rows. Conservation tillage leaves a higher 

rate of plant residue and increases soil organic matter (Hussain et al., 1999; Towery and 

Werblow, 2010), which benefit soil biota by providing additional food sources (energy) (USDANRCS, 1996). In addition, invertebrates that feed on plant detritus and their predators as well as 

the birds and other wildlife that feed on them, may benefit from increases in conservation tillage 

practices (Towery and Werblow, 2010; Carpenter, 2011). Ground-nesting and seed-eating birds, 

in particular, have been found to benefit from greater food and cover associated with 

conservation tillage (SOWAP, 2007).

In addition to conservation tillage, habitat can be maintained on agricultural lands by managing 

field edges for wildlife and using several cultural practices such as crop rotations, planting 
42

grassed terraces, and contour strip planting. Field edges are often not productive, and the cost 

for cultivation can exceed the crop value (Sharpe, 2010). Field edges that are allowed to return 

to volunteer plants such as ragweed (Ambrosia), goldenrod (Solidago), and aster (Aster L.) can 

quickly become suitable habitat for game birds and songbirds (Sharpe, 2010). Rotating crops 

with small grains or meadow crops not only serves to reduce erosion and enhance soil properties, 

this practice also increases plant diversity and provides forage and cover for several wildlife 

species (Brady, 1985; Sharpe, 2010). Similarly, planting crops in strips along the natural contour 

of the slope and along grass or fallow strips, otherwise known as contour strip cropping, also 

increases plant diversity and provide beneficial wildlife habitat (Brady, 1985; Sharpe, 2010). 

Herbicide use in agricultural fields may impact biodiversity by decreasing weed quantities or 

causing a shift in weed species present in the field, which may affect those insects, birds, and 

mammals that utilize these weeds. The quantity and type of herbicide use associated with GE 

crops, however, is dependent on many variables, including cropping systems, type and 

abundance of weeds, production practices, and individual grower decisions.

Landscape-scale Diversity 

The greatest direct impact of agriculture on biodiversity on the landscape scale results from the 

loss of natural habitats caused by the conversion of natural ecosystems into agricultural land 

(Ammann, 2005). A literature review by Carpenter (2011) revealed that increases in crop yields, 

such as may be attained with GE crops (including herbicide-resistant corn) have the potential to 

reduce impacts to biodiversity by allowing less land to be converted to agriculture than would 

otherwise be necessary; however, substantial gains in yields have generally not been obtained by 

herbicide-resistant cultivars unless higher yielding cultivars are modified with an herbicideresistant trait (NRC, 2010). 

As with farm-scale diversity, use of herbicides at the landscape scale also has the potential to 

impact biodiversity. Area-wide herbicide application may increase certain populations of 

invertebrates and wildlife that benefit from conservation tillage, whereas species that are 

dependent on the targeted weeds may be negatively impacted. 

Further, potential impacts to landscape-scale diversity can be related to the effects of herbicides 

on non-target animal and plant species. Assessments of the toxicity of glyphosate to animal 

species indicate a minimal risk to animals, but it may cause adverse effects to plants composing 

the animals’ habitat. As discussed in Subsection 2.3.1, Animal Communities, glyphosate was 

found by the EPA to be no more than slightly toxic to birds, moderately toxic to practically 

nontoxic to fish, and practically nontoxic to aquatic invertebrates and honeybees (US-EPA, 

1993b). Spraying herbicides onto crops has the potential for inadvertent contact and damage to 

non-target plants; the EPA is currently evaluating additional labeling requirements concerning 

BMPs for controlling pesticide spray drift (see Subsection 2.3.2, Plants Communities). While 

herbicide use potentially affects biodiversity, the application of pesticides in accordance with 

registered uses and label instructions, and careful management of chemical spray drift, 

minimizes the potential impacts from their use. 

In 2009, the EPA initiated reregistration of glyphosate and has identified additional data needs. 

Part of the risk assessment will include an acute avian oral toxicity study for passerine species. 

Additionally, some inert ingredients used as surfactants are more toxic than glyphosate to aquatic 
43

organisms, and will be evaluated for acute toxicity to estuarine and marine mollusk, 

invertebrates, and fish (US-EPA, 2009b). 

2.4 Human Health

Corn is used for food, feed, and various other products to which people are exposed. One 

component of the affected environment is the direct human consumption of products derived 

from corn, as described below. This section also addresses exposure to pesticides used on corn.

The majority of corn produced in the U.S. is field or “dent” corn (named for the dent at the 

crown of the mature kernel) (USGC, 2010). Field corn is used in a multitude of products which 

are also either directly or indirectly consumed by humans. Directly consumed corn products 

include corn syrup and sweeteners, starches, oil, cereal, beverage and industrial alcohol, and 

cosmetics and other personal hygiene products containing corn ingredients (USGC, 2010). In 

the 2010/2011 market year, these products totaled 12.2% of domestic field corn consumption 

(USDA-ERS, 2011g). In 2010, the average per capita consumption of corn food products was 

102.2 pounds, 69.2 pounds of which was corn sweeteners (USCB, 2011). The major use of corn 

indirectly consumed by humans is in the form of livestock feed; in the 2010/11 market year,

approximately 42.8% of domestic corn consumption was for feed and residual use (USDA-ERS, 

2011g). Also in the 2010/11 market year, the U.S. produced about 12.4 billion bushels (315 

million metric tons) of corn, 88% of which (10.9 billion bushels or 277 million metric tons) were 

GE varieties and 72% (8.9 billion bushels or 226 million metric tons) that was genetically 

engineered for herbicide resistance (USDA-ERS, 2011a; USDA-ERS, 2011g). Starch and oil 

fractions obtained from wet or dry milling processes produce products such as corn syrup and 

corn oil for direct human consumption (CERA, 2010). 

Some of the commonly raised human health concerns associated with GE crops include the 

potential toxicity of the introduced genes and their products, the expression of new antigenic 

proteins, or altered levels of existing allergens (Malarkey, 2003; Dona and Arvanitoyannis, 

2009). All forms of genetic modification, including natural and human-mediated, have the 

potential for unexpected and unintentional compositional changes (NRC, 2004). The potential 

for compositional changes to impact human health is dependent on the nature of the altered 

substances and biological effects of the compounds. Previous studies of the EPSPS protein, 

which confers glyphosate resistance, found that the EPSPS proteins expressed through genetic 

engineering pose no potential for toxicity or allergenicity (Harrison et al., 1996; Ridley et al., 

2002; Batista et al., 2005; Hoff et al., 2007; Herouet-Guicheney et al., 2009). For example, in a 

study to evaluate the safety of the 2mEPSPS7 protein in corn, Herouet-Guicheney et al. (2009)

found that the 2mEPSPS protein is highly similar, both structurally and functionally, to the wildtype8 EPSPS protein found in nature, and does not have an amino acid sequence similar to any 

known allergenic or toxic protein. Similarly, in a study of the allergenicity of the CP4 EPSPS9

protein in GE corn and soybean to potentially sensitive humans, Batista et al. (2005) found that 

none of the individuals tested reacted differently to either the transgenic or wild-type maize 

samples. 

 7 The 2mEPSPS protein differs from the wild-type corn EPSPS protein as a result of the substitution of two amino 

acids in the genetic sequence.

8 The natural state, or non-mutated gene that encodes the normal genetic function. 9 The CP4 EPSPS protein is derived from the Agrobacterium sp. strain CP4.
44

An additional concern with GE food crops is the potential for increased levels of anti-nutrients, 

the compounds that interfere with the digestion of proteins, fats, and carbohydrates or the 

absorption of essential elements in the digestive tract (Dona and Arvanitoyannis, 2009). There 

are several naturally occurring anti-nutrients found in corn, including phytic acid, DIMBOA10, 

raffinose, and low levels of trypsin and chymotrypsin inhibitors (OECD, 2002). In a comparison 

of the nutritional profile of the glyphosate-resistant corn variety NK603, which expresses the 

CP4 EPSPS protein for glyphosate resistance, and non-GE corn, Ridley et al. (2002) found that 

the genetic modification to confer glyphosate resistance did not significantly change any of the 

51 biologically and nutritionally important components evaluated. 

Under the FFDCA, it is the responsibility of food and feed manufacturers to ensure that the 

products they market are safe and properly labeled. Food and feed derived from GE corn must 

be in compliance with all applicable legal and regulatory requirements. GE organisms for food 

and feed may undergo a voluntary consultation process with the FDA prior to release onto the 

market. Although a voluntary process, thus far all applicants who wish to commercialize a GE 

variety that will be included in the food supply have completed a consultation with the FDA. In 

a consultation, a developer who intends to commercialize a bioengineered food meets with the 

agency to identify and discuss relevant safety, nutritional, or other regulatory issues regarding 

the bioengineered food and then submits to FDA a summary of its scientific and regulatory 

assessment of the food. The FDA evaluates the submission and responds to the developer by 

letter (US-FDA, 2012b).

Stine has provided the FDA with information on the identity, function, and characterization of 

the genes for Maize Line HCEM485, including the expression of gene products. A

biotechnology consultation of the EPSPS protein was completed by the FDA on the GA21 corn 

variety (Biotechnology Notification File (BNF) No. 000051) on February 10, 1998 (US-FDA, 

1998a). According to the consultation note, 

“Monsanto has concluded that corn containing transformation event 

GA21 is not materially different in composition, nutrition, and 

safety from corn currently grown, processed, marketed, and 

consumed for animal feed or human food. At this time, based on 

Monsanto's description of its data and analyses, the Agency 

considers Monsanto's consultation on corn from varieties containing 

transformation event GA21 to be complete.”

Stine submitted a safety and nutritional assessment of food and feed derived from Maize Line 

HCEM485 to the FDA in December 2010 in support of the consultation process with the FDA 

for the commercial distribution of Maize Line HCEM485 (Stine, 2011). 

The allergy potential of a GE food crop is also part of the safety evaluation conducted by FDA. 

Food allergies are caused by parts of the food or ingredients, usually proteins, which are 

recognized by the body’s immune cells causing a reaction. There have been reported cases of 

corn allergies; however, the protein(s) that may be responsible has not been identified (CERA, 

 10 2,4-Dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one (DIMBOA) belongs to a group of metabolites, 

hydroxamic acids and benzoxazinoids that are frequently found in cereal crops.
45

2010). Some foods only cause an allergic reaction when eaten raw, while others such as corn 

may or may not be allergenic, depending on how they are processed (i.e. corn oil versus corn 

grain) (NIAID, 2011). The Food Allergen Labeling and Consumer Protection Act of 2004 

(FALCPA) identified the eight most-common allergenic foods which account for 90% of food 

allergic reactions; however, corn is not included on this list (US-FDA, 2012a). The EPSPS 

protein expressed in Maize Line HCEM485 has the same molecular weight and immunochemical 

cross-reactivity as that of GA21 corn (Stine, 2011), and was determined:

• not to be a known allergen;

• not to have a gene sequence homology (similarity in structure) to known allergens or 

toxins; 

• to have a gene sequence homology 99.3% the same as the wild-type corn enzyme and 

other EPSPS proteins found in food crops;

• to be rapidly degraded in the gut; and

• dietary exposure to the protein is very low (US-FDA, 1998a; CERA, 2010).

Corn allergies are, therefore, not very common, but because corn starch, syrup, and oil are used 

in so many products not readily identifiable as potentially containing corn, those with corn food 

allergies must carefully read all food labels (More, 211). 

In 2010, pesticides were applied to 98% of planted corn acres, and of that, approximately 66% of 

all active ingredients applied were herbicides (USDA-NASS, 2011c). Insecticides and 

fungicides made up approximately 8% and 12% of active ingredients, respectively. The 

herbicides most widely used on corn in 2010 in order of prevalence were glyphosate applied to 

66% of treated acres, followed by atrazine (61%) and acetochlor (25%) (USDA-NASS, 2011c). 

Under the FIFRA, all pesticides (which is inclusive of herbicides, insecticides and fungicides) 

sold or distributed in the U.S. must be registered by the EPA (US-EPA, 2011a). Registration 

decisions are based on scientific studies that assess the chemical’s potential toxicity and 

environmental impact. To be registered, a pesticide must be able to be used without posing 

unreasonable risks to people or the environment. All pesticides registered prior to November 1, 

1984, such as glyphosate, must also be reregistered to ensure that they meet the current, more 

stringent standards and have a reregistration review every 15 years (US-EPA, 2011a). 

Glyphosate was first registered in the U.S. in 1974; the latest reregistration decision for 

glyphosate was issued in 1993 (US-EPA, 1993b; US-EPA, 2009b; US-EPA, 2009a). It is 

currently under reregistration review, which began in July 2009 and is scheduled for completion 

in 2015 (US-EPA, 2009a). 

Pursuant to the FFDCA, before a pesticide can be used on a food crop the EPA must establish 

the tolerance value, which is the maximum amount of pesticide residue that can remain on the 

crop or in foods processed from that crop (US-EPA, 2011j). The USDA has implemented the 

Pesticide Data Program (PDP) in order to collect data on pesticides residues on food (USDAAMS, 2010). The EPA uses PDP data to prepare pesticide dietary exposure assessments 

pursuant to the 1996 Food Quality Protection Act. Pesticide tolerance levels for glyphosate have 

been established for a wide variety of commodities, including field corn for grain and forage, and 

are published in the Federal Register, 40 CFR §180.364, and the Indexes to Part 180 Tolerance 
46

Information for Pesticide Chemicals in Food and Feed Commodities (US-EPA, 2011e). 

Glyphosate tolerance for corn grain is 5.0 parts per million (ppm) (40 CFR §180.364). 

Glyphosate is registered under a variety of trade names (e.g., Roundup®, Roundup Ultra®, 

Glyphomax Plus®, and Abundit Extra®) by several companies. There are currently over 400 

active glyphosate products registered under FIFRA Section 3, and over 100 registered for use on 

terrestrial food crops (US-EPA, 2009b). As mentioned above, it was the most widely-used 

herbicide on corn in 2010, applied to 66% of herbicide-treated acres in the U.S. (USDA-NASS, 

2011c). In that year, the average application rate was approximately 1.07 lb/Ac, with a total of 

over 57.5 million pounds applied (USDA-NASS, 2011c). When corn treated with glyphosate 

may be harvested for food varies by particular formulation. Glyphosate is classified as Toxicity 

Category III or IV11, having been found to have low toxicity via the oral, dermal, and inhalation 

routes (US-EPA, 2009c). Similarly, glyphosate is not classified as a carcinogen or teratogen 

(US-EPA, 2009c) While neurotoxicity has not been observed in previous studies, new data 

requirements established under 40 CFR part 158 require acute and subchronic neurotoxicity 

studies, and an immunotoxicity study to take place for reregistration. The next RED for 

glyphosate is scheduled to be complete in 2015 (US-EPA, 2009a). Based on toxicological 

considerations, the EPA Health Effects Division (HED) determined that the main metabolite of 

glyphosate, AMPA, did not need regulation despite levels observed in foods or feed (US-EPA, 

2009c).

The EPA published the Worker Protection Standard (WPS) pursuant to 40 CFR part 170 in 1992 

for the purpose of reducing the risk of pesticide poisonings and injuries among agricultural 

workers and pesticide handlers (US-EPA, 2011k). The WPS offers protections to about 2.5 

million agricultural workers who work with pesticides at more than 600,000 agricultural 

workplaces (e.g., farms, forests, nurseries, greenhouses). The WPS contains requirements for 

pesticide safety training, notification of pesticide applications, use of personal protective 

equipment (PPE), restricted entry intervals following pesticide application, decontamination 

supplies, and emergency medical assistance.

Growers are required to use pesticides consistent with the application instructions provided on 

the EPA-approved pesticide labels. For example, pesticide labels specify the appropriate worker 

safety practices that must be followed, including the necessary PPE to be worn by mixers, 

loaders, other applicators and handlers. These label restrictions carry the weight of law and are 

enforced by the EPA and the states (FIFRA 7 U.S.C. 136j (a)(2)(G) Unlawful Acts); therefore, it 

is expected that glyphosate use on Maize Line HCEM485 would be consistent with the EPAapproved labels.

2.5 Animal Feed

U.S. animal agriculture consumed approximately 44% of U.S. corn usage and approximately 127 

million metric tons of corn in 2010 (USDA-ERS, 2011g; USDA-ERS, 2011d). As with human 

consumption of corn, the majority of corn used for animal feed in the U.S. is herbicide resistant 

(USDA-ERS, 2011a). Corn typically accounts for approximately 96% of the total feed grain 

produced for use in the U.S. (USDA-ERS, 2011d). According to the National Corn Growers 

Association, beef cattle consume the largest volume of U.S. corn feed, followed by poultry, 

 11 Category I indicates the highest degree of acute toxicity and Category IV the lowest.
47

swine, and dairy cattle (NCGA, 2011). Corn is used as livestock feed in the form of forage, 

silage, feed-grain, and refined feed products. The amount of corn that is used for feed is 

dependent on the number of animals (livestock and poultry) that are fed corn and the supply and 

price of the crop (USDA-ERS, 2011d). Also taken into account is the amount of supplemental 

ingredients added to feed and the supply and price of competing ingredients.

Corn silage is commonly used as livestock feed. In 2010, corn was grown for silage in the U.S. 

on approximately 5.5 million acres and produced approximately 0.97 million metric tons

(USDA-NASS, 2011e). Corn silage is consumed primarily by beef and dairy cattle (Staples, 

2003; Sewell and Wheaton, 2011), swine (Kephart et al., 2012), sheep, and goats (Schoenian, 

2009; OMAFRA, 2011). More than half of all corn feed consists of grain corn. Corn grain is 

further refined into feed by dry milling, wet milling, and as by-products from distilleries (CRA, 

2006). Corn refiners produce five major animal feed products in the form of gluten meal, gluten 

feed, corn germ meal, condensed fermented corn extractives (steepwater), and amino acids 

(CRA, No Date). Dairy and beef cattle, poultry, swine, sheep, pets, and fish are fed refined corn 

products that are good sources of protein, fiber, minerals, and vitamins (CRA, 2006). Amino 

acids such as lysine, threonine, and tryptophan are produced from corn dextrose, providing 

nutrient supplements in animal feed; lysine is particularly valued for poultry and swine (CRA, 

2006). Corn may also be grown solely for grazing by cattle, goats, sheep, and swine (Hoorman 

et al., 2002). While annuals, such as corn, make excellent pasture crops and have the 

compositional value to meet many of the nutritional needs of livestock, they are generally more 

expensive than perennials typically used in pastures (Hoorman et al., 2002; Aasen, 2010). In 

some states, such as Illinois and Kentucky, grazing corn is recommended as a viable option for 

extending the grazing season, especially for producers with limited land area (USDA-NRCS, 

2000; Ditsch et al., 2004). Corn varieties recommended for grazing include hybrids 

recommended for silage (Aasen, 2010). Glyphosate-resistant varieties may be used, but 

herbicide application restrictions apply and are dependent on the type and timing of application 

(Bradley et al., 2010).

Similar to the regulatory control for direct human consumption of corn under the FFDCA, it is 

the responsibility of feed manufacturers to ensure that the products they market are safe and 

properly labeled. Feed derived from GE corn, like all corn, must comply with all applicable 

legal and regulatory requirements, which in turn protects human health. To help ensure 

compliance, GE organisms used for feed may undergo a voluntary consultation process with the 

FDA before release onto the market, which provides the applicant with any needed direction 

regarding the need for additional data or analysis, and allows for interagency discussions 

regarding possible issues. 

Although a voluntary process, thus far all applicants who wish to commercialize a GE 

variety that will be included in the food supply have completed a consultation with the FDA. 

In a consultation, a developer who intends to commercialize a bioengineered food meets 

with the agency to identify and discuss relevant safety, nutritional, or other regulatory issues 

regarding the bioengineered food and then submits to FDA a summary of its scientific and 

regulatory assessment of the food (US-FDA, 2012b). The FDA evaluates the submission 

and responds to the developer by letter. Stine submitted their final food consultation regarding 

Maize Line HCEM485 in December 2010 and is pending review by the FDA. It will be posted 

on the FDA website Final Biotechnology Consultations http://www.fda.gov/Food/Biotechnology 
48

/Submissions/ucm225108.htm when completed. A biotechnology consultation of the EPSPS 

protein was completed by the FDA on the GA21 corn variety (BNF No. 000051) on February 10, 

1998 (US-FDA, 1998a). No food safety issues were found by the FDA in their review of 

Monsanto’s safety and nutritional assessment of GA21 corn and the modified EPSPS protein. 

As described in Subsection 2.4, Human Health, under FIFRA, all pesticides (including 

herbicides) sold or distributed in the U.S. must be registered by the EPA (US-EPA, 2011a). All 

pesticides registered prior to November 1, 1984, such as glyphosate, must also be reregistered to 

ensure that they meet the current, more stringent standards and should have a reregistration 

review every 15 years (US-EPA, 2011a). The latest reregistration decision for glyphosate was 

issued in 1993 and the reregistration review was started in July 2009 (US-EPA, 2009b; US-EPA, 

2009a). Before a pesticide can be used on a food or feed crop, the EPA must establish the 

tolerance value, which is the maximum amount of pesticide residue that can remain on the crop 

or in foods or feed processed from that crop (US-EPA, 2011j; US-EPA, 2011e). Pesticide 

tolerance levels for glyphosate have been established for corn and are published in the Federal 

Register, CFR, and the Indexes to Part 180 Tolerance Information for Pesticide Chemicals in 

Food and Feed Commodities (US-EPA, 2011e). The glyphosate tolerance level established for 

field corn intended for forage is 6.0 ppm and for grain corn is 5.0 ppm (40 CFR §180.364). 

2.6 Socioeconomic

2.6.1 Domestic Economic Environment

The value of U.S. corn production exceeded $66.7 billion in 2010 (USDA-NASS, 2011f) which 

was 41.7% of the total value of field crops (Figure 6). Corn is among the most important field 

crops in the U.S. and has been increasing in importance over the past decade (Figure 7). 

Thirteen states (Iowa, Illinois, Nebraska, Minnesota, Indiana, Kansas, Ohio, South Dakota,

Wisconsin, Missouri, Michigan, Texas, and North Dakota) that produced at least one billion 

dollars’ worth of corn in 2010 also accounted for more than 90% of U.S. production (USDANASS, 2011f). These states are widely distributed across resource regions defined by the ERS

as the Heartland (Illinois, Indiana, Iowa, Minnesota, Missouri, Nebraska, Ohio, and South 

Dakota), Northern Crescent (Michigan, Minnesota, Ohio, and Wisconsin), Northern Great Plains 

(Minnesota, Nebraska, North Dakota, and South Dakota), Prairie Gateway (Kansas, Nebraska, 

and Texas), Eastern Uplands (Missouri and Ohio), Fruitful Rim (Texas), and Southern Seaboard 

(Texas) resource regions (Fernandez-Cornejo and McBride, 2002). These regions vary in terms

of land productivity and cost of production (Figure 8). The most productive of these regions are 

the Heartland and Northern Crescent. The two most profitable regions, the Heartland and 

Northern Great Plains, are most profitable for different reasons. The Heartland benefits from 

greater productivity, while the Northern Great Plains benefits from lower production costs. 
49

Source: (USDA-NASS, 2011f)

Figure 6. Percentage distribution of 2010 U.S. crop value among corn, soybean, hay, 

wheat, and other crops. Corn is among the most important field crops in the U.S. as its 

value of production was 41.7% of the total value of field crops in 2010.

Source: (USDA-NASS, 2004; USDA-NASS, 2005; USDA-NASS, 2006; USDA-NASS, 

2007b; USDA-NASS, 2008b; USDA-NASS, 2009b; USDA-NASS, 2010b; USDANASS, 2011f)

20

25

30

35

40

45

Percent of Field Crop Value

Year
50

Figure 7. Value of U.S. corn crop as a percent of all U.S. field crops from 2001 to 2010. 

Note the value of corn has increased since 2001, indicating its growing importance in U.S. 

agriculture.

Source: (USDA-ERS, 2011c)

Figure 8. U.S. corn per acre cost and value of production estimates in major ARMS 

corn- producing regions and the entire U.S. in 2010. Values presented exclude government 

payments. States comprising the regions include: Heartland (Illinois, Indiana, Iowa, 

Minnesota, Missouri, Nebraska, Ohio, and South Dakota), Northern Crescent (Michigan, 

Minnesota, Ohio, and Wisconsin), Northern Great Plains (Minnesota, Nebraska, North 

Dakota, and South Dakota), Prairie Gateway (Kansas, Nebraska, and Texas), Eastern 

Uplands (Missouri and Ohio), Fruitful Rim (Texas), and Southern Seaboard (Texas) 

resource regions (Fernandez-Cornejo and McBride, 2002). These regions vary in terms of 

land productivity and cost of production. 

Production cost data are provided by the ERS and collected in surveys conducted every four to 

eight years for each commodity as part of the annual ARMS (USDA-ERS, 2011b). In 2010, 

typical corn production operating costs were reported in dollars per planted acre, and included

primarily purchased seed ($83.22), fertilizer and soil amendments ($101.03), other chemicals 

($26.86), and irrigation water ($0.15) (USDA-ERS, 2011c). In 2010, total-operating costs for 

U.S. corn production were $275.58 per planted acre (USDA-ERS, 2011c).

Almost all of the U.S. corn supply (99.8% in 2010/11) comes from new annual domestic 

production (USDA-ERS, 2011g). Over the past decade this production has increased 25.5% 

$0.00

$100.00

$200.00

$300.00

$400.00

$500.00

$600.00

$700.00

$800.00

U.S. Heartland Northern

Cresent

Northern

Great

Plains

Prairie

Gateway

Eastern

Uplands

Southern

Seaboard

Per Acre

ARMS Resource Region

Cost

Value
51

from 2001 to 2010. In 2010/11, 86.2% of this supply was consumed domestically. Consumption 

patterns have changed substantially over the past decade. In the 2000/01 marketing year, 

approximately 75% of the domestic use was for animal feed, whereas only about 8.1% was used 

for ethanol production. In the 2010/11 marketing year, less than half (42.8%) of domestic usage 

was for feed, while approximately 44.7% of domestic use was for the production of ethanol, 

which has been supported by government policies designed to promote domestic renewable 

energy sources. Similarly, the percentage of corn used for food products (e.g., corn syrup, 

starch, alcohol for beverages, cereals and other products) decreased between the 2000/01 and 

2010/11 marketing years from 19.3% to 12.2% (USDA-ERS, 2011g). Corn use for seed over 

this period has remained steady at approximately 0.2% (USDA-ERS, 2011g).

The first commercial herbicide-resistant variety of corn was released in 1996 that had conferred 

resistance to glufosinate, followed in 1998 by glyphosate-resistant corn (Green and Owen, 2011). 

Herbicide-resistant corn varieties have been more slowly adopted than other such crops, but now 

account for 72% of U.S. corn acreage in 2011(Brookes and Barfoot, 2010; USDA-ERS, 2011a). 

As discussed in Subsection 2.1.1, Acreage and Area of Corn Production, herbicide-resistant corn 

adoption has varied regionally in the U.S., with South Dakota leading the planting of herbicideresistant-only and herbicide-resistant stacked GE varieties since 2000, and Ohio planting the 

least (USDA-ERS, 2011a) (see Subsection 2.1.1, Acreage and Area of Production, Figure 4). In 

2005, 31% of U.S. corn was glyphosate-resistant and 4% was glufosinate-resistant (Sankula, 

2006). 

Estimates of the benefits of herbicide-resistant corn to farmers are limited (NRC, 2010). For 

specialized corn farmers, each time farmers increase herbicide-resistant corn production 10%, 

Fernandez-Cornejo and McBride (2002) found a 2.7% increase in whole farm net returns, while 

McBride and El-Osta (2002) found a 2.7% increase in crop operating margin. McBride and ElOsta (2002) did not find higher crop operating margins for herbicide-resistant corn farmers in 

general, which includes those that rotate corn with other crops. In an examination of research 

into U.S. farm-level economic impacts of GE crops, the National Research Council (NRC)

(2010) found studies indicate in the early years of the adoption, GE cultivars exerted downward 

pressure on crop prices while the earnings of adopting farmers increased, and barriers to access 

of GE crops reduced grower income. Now that the adoption of GE cultivars is more widespread 

globally, the NRC recommends further assessment of the farm-level economic impacts of GE 

crops (NRC, 2010).

Costs of Herbicide-resistant Weeds

An important concern currently facing U.S. farmers, including corn farmers, is the emergence of 

glyphosate-resistant weeds (Johnson and Gibson, 2006; Foresman and Glasgow, 2008; Hurley et 

al., 2009a; Johnson et al., 2009), a result of the repeated, wide spread, and sometimes exclusive 

use of glyphosate on corn, cotton, and soybean crops resistant to the pesticide (Beckie, 2006; 

Duke and Powles, 2009). As of the 2010 growing season, there were 13 different weed species 

with glyphosate-resistant populations ranging across 25 different U.S. states (Heap, 2011) (see 

Subsection 2.3.2, Plants Communities, Table 2). Glyphosate-resistant weed populations have 

been found in all but 3 (South Dakota, Wisconsin, and Texas) of the 13 major corn producing 

states. Comparing the typical glyphosate-resistant weed management programs to a typical

nonherbicide-resistant weed management program, Sankula and Blumenthal (2004) and Sankula 
52

(2006) estimated that farmers saved $9.49 to $10.15 per acre in weed management costs. Based 

on 2007 survey data, Hurley, Mitchell, and Frisvold (2009b) found that farmers planting more 

glyphosate-resistant corn reported lower weed management costs.

Surveys indicate that farmers prefer to address glyphosate-resistant weeds by using additional 

herbicides with different modes of action (Johnson and Gibson, 2006; Foresman and Glasgow, 

2008; Johnson et al., 2009). Weirich et al. (2011) investigated the effect of grower adoption of 

alternative glyphosate weed resistance management programs, finding they increased cost 

substantially, though they did not statistically significantly decrease net returns due to higher 

yields. These results suggest that growers may be able to effectively respond to glyphosate 

resistance using weed BMPs without substantially affecting their returns.

Organic Crop Production

Organic crop production represents an extremely small share of U.S. production. In 2008, there 

were approximately 2.2 to 2.6 million acres of certified organic cropland representing about 

0.70% of the total cropland acres (USDA-ERS, 2010a; USDA-NASS, 2010a). There were only 

194,637 acres of organic corn representing 0.05% of total cropland and 0.21% of the total corn 

acres in 2008 (USDA-ERS, 2010a). More than 80% of this production was concentrated in 10 

states (Wisconsin, Minnesota, Iowa, Michigan, New York, Texas, Nebraska, Ohio, Illinois, and 

Pennsylvania), with the top 2 states (Wisconsin and Minnesota) representing almost a third of 

these acres (USDA-ERS, 2010b). All but New York and Pennsylvania are among the top 13 

corn producing states. The value of corn produced for grain or seed from organic-certified farms 

in the U.S. in 2008 was nearly $111.4 million (USDA-NASS, 2010a).

2.6.2 Trade Economic Environment

The Cartagena Protocol on Biosafety is a treaty under the United Nations Convention on 

Biological Diversity (CBD) that established a framework for the safe transboundary movement, 

with respect to the environment and biodiversity, of Living Modified Organisms (LMOs), 

including those modified through biotechnology. See Subsection 7.1.2, International 

Implications, for a more extensive discussion of the Cartagena Protocol. Although the U.S. is 

not a party to the CBD, Parties to the Protocol have developed regulations to comply with it

which U.S. exporters must adhere.

Agricultural exports represented $137.4 billion or 10% of the total value of U.S. exports in the 

2011 fiscal year (USDA-ERS, 2010d). Approximately 15% of U.S. corn production is destined 

for export (USDA-ERS, 2009). Corn exports worth $9.1 billion ranked second only to bulk 

soybean exports, and accounted for 8.4% of all U.S. agricultural exports (USDA-ERS, 2010c). 

In the 2010/11 marketing year (extending from September to August), the U.S. accounted for 

more than half of all global corn exports (46.0 million metric tons), while Argentina and Brazil 

accounted for another 25%, exporting 15.0 and 11.0 million metric tons, respectively (USDAFAS, 2011a). Over the past decade, U.S. corn exports have remained relatively stable, while 

global exports have increased by almost 20%, eroding the U.S. export share (Figure 9). This is 

attributed to greater domestic use of U.S. corn, smaller corn crops, and increased competition 

from other major corn exporters such as Argentina, Brazil, and Ukraine (USDA-FAS, 2011a). 

U.S. exports tend to increase when there is a large domestic supply, prices are competitive, and 
53

foreign demand increases (USDA-ERS, 2009), illustrated by record exports in 2007/2008 

(Figure 9). 

Source: (USDA-FAS, 2004; USDA-FAS, 2005; USDA-FAS, 2006; USDA-FAS, 2007; USDAFAS, 2008a; USDA-FAS, 2009; USDA-FAS, 2010a; USDA-FAS, 2011a)

Figure 9. U.S. and world corn exports in million metric tons for marketing years 

2000/01 to 2010/11. Market years extend from September to August. The rest of the world 

major exporters include Argentina, Brazil, Canada, China, EU-27, India, Paraguay, 

Romania, Serbia, South Africa, Thailand, Ukraine, and Zambia as well as other smaller 

exporting countries. Note that U.S. percentage of corn exports in relation to overall world 

exports declined at the end of the last decade.

Table 4 includes the quantities of U.S.-produced corn imported by the 10 largest importing 

countries spanning 2010 and 2011. Japan, Mexico, and South Korea were the top three

importers of U.S. corn for those periods (USDA-ERS, 2011h), consuming approximately 31%, 

17%, and 13% of total U.S. corn exports, respectively. Where U.S. corn will be exported is 

subject to global market conditions shaped by many factors such as the value of the U.S. dollar 

and other currencies, oil prices, U.S. and international agricultural policy, the U.S. and 

international biofuels sector, livestock and meat trade, prices, and population growth (USDAERS, 2009; USDA-OCE, 2011). In the case of GE crops and derived food and feed, consumer 

perception of GE products can create trade barriers (Fernandez-Cornejo and Caswell, 2006). The 

primary U.S. corn export destinations are also the largest world importers of corn and do not 

seem to have major barriers for importing GE products. For example, as of 2006, Japan has 

approved 75 biotech modifications for food, 59 for feed and 55 for planting (Hamamoto, 2006). 

Commercialization of domestic and imported biotech plant products requires environmental, 

food and feed approvals in Japan, and strict labeling on all biotech food products is required. In 

addition to national regulations, there are also local requirements in some areas of Japan 

(Hamamoto, 2006). Mexico imports and consumes existing varieties of GE corn and has passed 

0

20

40

60

80

100

120

Million Metric Tons

Marketing Year (Sept.-Aug.)

Rest of

World

United States
54

legislation that would enable experimental releases of GE corn crops, and, potentially, 

commercial production (USDA-FAS, 2008b; USDA-FAS, 2010b). South Korea has adopted the 

Cartagena Protocols on Biosafety, thus has processes requiring environmental, food and feed 

safety approvals for imported GE crops for cultivation, food, and feed, but has not produced 

Table 4. Largest importers of U.S. corn in the 2010/11 Season.

Location

October 2009-

August 2010

October 2009-

August 2011 August 2010 August 2011

(Million Metric Tons)

Japan 13.76 13.16 1.32 0.85

Mexico 7.63 6.86 0.62 0.67

South Korea 6.20 5.54 0.74 0.57

Taiwan 2.88 2.65 0.32 0.11

Egypt 2.30 2.74 0.28 0.44

Canada 1.81 0.80 0.11 0.16

China 1.20 0.67 0.49 0.18

Venezuela 1.05 0.79 0.15 0.16

Dominican Republic 0.88 0.68 0.06 0.03

Colombia 0.85 0.48 0.03 0.01

World Total 45.23 42.11 4.72 3.82

Source: (USDA-ERS, 2011h)

biotechnology crops (USDA-FAS, 2011b); they have, however, approved field trials of certain 

biotech crops. The majority of GE corn imported to South Korea is used for animal feed, which 

is nearly all GE in that country (USDA-FAS, 2011b). Processed corn products such as corn 

syrup or corn oil are exempt from labeling there because they contain miniscule amounts of 

biotech protein (USDA-FAS, 2011b), but other food and animal feed require labeling. Surveys 

consistently find that consumers around the world have concerns about food derived from GE 

crops (Fernandez-Cornejo and Caswell, 2006) that has led to labeling requirements in many 

countries, and some retailers are reluctant to stock GE-labeled food, creating a barrier to trade. 

The U.S. produced 316.2 million metric tons of corn in the 2010/11 marketing year, which 

represented 38.6% of world production (USDA-FAS, 2011a). U.S. corn production has 

remained relatively stable over the last decade, but the U.S. share of world production has 

declined even as total world production increased by 39.8% (Figure 10). The other major 

producers of corn are China and Brazil, producing respectively 21.0% (173.0 million metric 

tons) and 7.0% (57.5 million metric tons) of global production in 2010/11. 

The U.S. and China are also the top 2 consumers of corn at 290.3 and 172.0 million metric tons, 

respectively, in the 2010/11 marketing year, comprising more than half of world consumption 

(Table 5) (USDA-FAS, 2011a). The European Union is the next largest consumer, accounting 

for 7.4% (62.3 million metric tons) of global consumption. Over the past decade, U.S. corn 

consumption has increased by 46.5%, primarily due to increased ethanol production, while world 

corn consumption increased by 38.6% (Figure 11) (USDA-FAS, 2004; USDA-FAS, 2005; 
55

USDA-FAS, 2006; USDA-FAS, 2007; USDA-FAS, 2008a; USDA-FAS, 2009; USDA-FAS, 

2010a; USDA-FAS, 2011a).

Source: (USDA-FAS, 2004; USDA-FAS, 2005; USDA-FAS, 2006; USDA-FAS, 2007; USDAFAS, 2008a; USDA-FAS, 2009; USDA-FAS, 2010a; USDA-FAS, 2011a)

Figure 10. U.S. and world corn production in million metric tons for marketing years 

2000/01 to 2010/11. Market years extend from September to August. The rest of the world 

major producing countries include Argentina, Brazil, Canada, China, Egypt, EU-27, India, 

Indonesia, Mexico, Nigeria, Philippines, Romania, Serbia, South Africa, Thailand, Turkey, 

and the Ukraine. Note that U.S. production increased slightly while its percentage of 

overall world corn production declined in the last decade.

Table 5. World corn consumption for marketing years (August to September) 

2008/2009 to 2010/2011.

Location 2008/09 2009/10 2010/11

(Million Metric Tons)

Brazil 45.5 47.0 49.5

Canada 11.7 11.6 11.3

China 153.0 159.0 172.0

Egypt 11.1 12.0 12.1

EU-271 61.6 59.5 62.3

India 17.0 15.1 18.3

Japan 16.7 16.3 15.6

Mexico 32.4 30.2 28.5

South Africa 9.9 10.3 10.6

United States 259.3 281.6 290.3

0

100

200

300

400

500

600

700

800

900

Million Metric Tons

Marketing Year (Sep.-Aug.)

Rest of

World

United States
56

Others 165.5 174.1 173.0

World Total 783.7 816.7 843.6

Source (USDA-FAS, 2011a)

1 European Union 27 member countries

Source (USDA-FAS, 2004; USDA-FAS, 2005; USDA-FAS, 2006; USDA-FAS, 2007; USDAFAS, 2008a; USDA-FAS, 2009; USDA-FAS, 2010a; USDA-FAS, 2011a)

Figure 11. U.S. and world corn consumption in million metric tons for marketing years 

2000/01 to 2010/11. Marketing years extend from September to August. The rest of the 

world major comsumers of corn include Brazil, Canada, China, Egypt, EU-27, India, 

Japan, Mexico, and South Africa. Note both U.S. and world corn consumption has 

increased over the last decade, although the U.S. percentage of overll world corn 

consumption has decreased. 

0

100

200

300

400

500

600

700

800

900

Million Metric Tons

Marketing Year (Sept.-Aug.)

Rest of

World

United States
57

3 ALTERNATIVES

This document analyzes the potential environmental consequences of APHIS’ response to 

Stine’s extension request for a determination of nonregulated status to Maize Line HCEM485. 

To respond favorably to a request for an extension of nonregulated status, APHIS must 

determine that Maize Line HCEM485 is similar to the antecedent organism, GA21 and is,

therefore, unlikely to pose a plant pest risk. Based on its PPRA (USDA-APHIS, 2011b), APHIS 

has concluded that Maize Line HCEM485 is similar to GA21 and is unlikely to pose a plant pest 

risk. Therefore APHIS must determine that Maize Line HCEM485 is no longer subject to 7 CFR 

part 340 or the plant pest provisions of the Plant Protection Act. 

Two alternatives are evaluated in this EA: (1) no action and (2) extension of a determination of 

nonregulated status to Maize Line HCEM485. APHIS has assessed the potential for 

environmental impacts for each alternative in the Environmental Consequences section.

3.1 No Action Alternative: Continuation as a Regulated Article

Under the No Action Alternative, APHIS would deny the extension request. Maize Line 

HCEM485 corn and progeny derived from Maize Line HCEM485 corn would continue to be 

regulated articles under the regulations at 7 CFR part 340. Permits issued or notifications 

acknowledged by APHIS would still be required for introductions of Maize Line HCEM485 corn 

and measures to ensure physical and reproductive confinement would continue to be 

implemented. APHIS might choose this alternative if there were insufficient evidence to 

demonstrate that Maize Line HCEM485 is similar to the antecedent organism, GA21. 

This alternative is not the Preferred Alternative because APHIS has concluded through a Plant 

Pest Risk Assessment that Maize Line HCEM485 corn is similar to the antecedent organism, 

GA21 and is unlikely to pose a plant pest risk (USDA-APHIS, 2011b). Choosing this alternative 

would not satisfy the purpose and need of making a determination of plant pest risk status and 

responding to the extension request for nonregulated status. 

3.2 Preferred Alternative: Approve the Request for an Extension of a 

Determination of Nonregulated Status to Maize Line HCEM485 from Corn 

Event GA21

Under this alternative, Maize Line HCEM485 corn and progeny derived from them would no 

longer be regulated articles under the regulations at 7 CFR part 340. Maize Line HCEM485 is 

unlikely to pose a plant pest risk (USDA-APHIS, 2011b). Permits issued or notifications 

acknowledged by APHIS would no longer be required for introductions of Maize Line 

HCEM485 corn and progeny derived from this event. This alternative best meets the purpose 

and need to respond appropriately to a request for an extension of a determination of 

nonregulated status based on the requirements in 7 CFR part 340 and the agency’s authority 

under the plant pest provisions of the Plant Protection Act. Because the agency has concluded 

that Maize Line HCEM485 corn is similar to the antecedent organism, GA21 and is unlikely to 

pose a plant pest risk, an extension of a determination of nonregulated status to Maize Line 

HCEM485 corn is a response that is consistent with the plant pest provisions of the Plant 

Protection Act, the regulations codified in 7 CFR part 340, and the biotechnology regulatory 

policies in the Coordinated Framework.
58

Under this alternative, growers may have future access to Maize Line HCEM485 and progeny 

derived from this event if the developer decides to commercialize Maize Line HCEM485. 

3.3 Alternatives Considered But Rejected from Further Consideration

APHIS assembled a list of alternatives that might be considered for Maize Line HCEM485. The 

agency evaluated these alternatives, in light of the agency's authority under the plant pest 

provisions of the Plant Protection Act, and the regulations at 7 CFR part 340, with respect to 

environmental safety, efficacy, and practicality to identify which alternatives would be further 

considered for Maize Line HCEM485. Based on this evaluation, APHIS rejected several 

alternatives. These alternatives are discussed briefly below along with the specific reasons for 

rejecting each.

3.3.1 Prohibit Any Maize Line HCEM485 Corn from Being Released

In response to public comments that stated a preference that no GE organisms enter the 

marketplace, APHIS considered prohibiting the release of Maize Line HCEM485 corn, including 

denying any permits associated with the field testing. APHIS determined that this alternative is 

not appropriate given that APHIS has concluded that Maize Line HCEM485 is similar to the 

antecedent organism, GA21 and is unlikely to pose a plant pest risk (USDA-APHIS, 2011b).

In enacting the Plant Protection Act, Congress found that 

[D]ecisions affecting imports, exports, and interstate movement of products regulated 

under [the Plant Protection Act] shall be based on sound science...§402(4).

On March 11, 2011, in a Memorandum for the Heads of Executive Departments and Agencies, 

the White House Emerging Technologies Interagency Policy Coordination Committee developed 

broad principles, consistent with Executive Order (EO) 13563, to guide the development and 

implementation of policies for oversight of emerging technologies (such as genetic engineering) 

at the agency level. In accordance with this memorandum, agencies should adhere to EO 13563 

and, consistent with that EO, the following principle, among others, to the extent permitted by 

law, when regulating emerging technologies: 

“[D]ecisions should be based on the best reasonably obtainable scientific, technical, 

economic, and other information, within the boundaries of the authorities and mandates 

of each agency” 

Based on the PPRA (USDA-APHIS, 2011b) and the scientific data evaluated therein, APHIS 

concluded that Maize Line HCEM485 is unlikely to pose a plant pest risk. Accordingly, there is 

no basis in science for prohibiting the release of Maize Line HCEM485. 

3.3.2 Isolation Distance between Maize Line HCEM485 and Non-GE Corn Production 

and Geographical Restrictions

In response to public concerns of gene movement between GE and non-GE plants, APHIS 

considered requiring an isolation distance separating Maize Line HCEM485 from conventional 

or specialty corn production. However, because APHIS has concluded that Maize Line 

HCEM485 is unlikely to pose a plant pest risk (USDA-APHIS, 2011b), an alternative based on 
59

requiring isolation distances would be inconsistent with the statutory authority under the plant 

pest provisions of the Plant Protection Act and regulations in 7 CFR part 340. 

APHIS also considered geographically restricting the production of Maize Line HCEM485 based 

on the location of production of non-GE corn in organic production systems or production 

systems for GE-sensitive markets in response to public concerns regarding possible gene 

movement between GE and non-GE plants. However, as presented in APHIS’ PPRA for Maize 

Line HCEM485, there are no geographic differences associated with any identifiable plant pest 

risks for Maize Line HCEM485 (USDA-APHIS, 2011b). This alternative was rejected and not 

analyzed in detail because APHIS has concluded that Maize Line HCEM485 does not pose a 

plant pest risk and will not exhibit a greater plant pest risk in any geographically restricted area. 

Therefore, such an alternative would not be consistent with APHIS’ statutory authority under the 

plant pest provisions of the Plant Protection Act and regulations in Part 340 and the 

biotechnology regulatory policies embodied in the Coordinated Framework.

Based on the foregoing, the imposition of isolation distances or geographic restrictions would not 

meet APHIS’ purpose and need to respond appropriately to an extension request for 

nonregulated status based on the requirements in 7 CFR part 340 and the agency’s authority 

under the plant pest provisions of the Plant Protection Act. However, individuals might choose 

on their own to geographically isolate their non-GE corn production systems from Maize Line 

HCEM485 or to use isolation distances and other management practices to minimize gene 

movement between cornfields. Information to assist growers in making informed management 

decisions for Maize Line HCEM485 is available from AOSCA(AOSCA, 2010).

3.3.3 Requirement of Testing for Maize Line HCEM485

During the comment periods for other petitions for nonregulated status, some commenters 

requested USDA to require and provide testing for GE products in non-GE production systems. 

APHIS notes there are no nationally-established regulations involving testing, criteria, or limits 

of GE material in non-GE systems. Such a requirement would be extremely difficult to 

implement and maintain. Additionally, because Maize Line HCEM485 does not pose a plant 

pest risk (USDA-APHIS, 2011b), the imposition of any type of testing requirements is 

inconsistent with the plant pest provisions of the Plant Protection Act, the regulations at 7 CFR 

part 340 and biotechnology regulatory policies embodied in the Coordinated Framework. 

Therefore, imposing such a requirement for Maize Line HCEM485 would not meet APHIS’ 

purpose and need to respond appropriately to the request in accordance with its regulatory 

authorities. 

3.4 Comparison of Alternatives 

Table 6 presents a summary of the potential impacts associated with selection of either of the 

alternatives evaluated in this EA. The impact assessment is presented in Section 4, 

Environmental Consequences of this EA. 
60

Table 6. Summary of issues of potential impacts and consequences of alternatives.

Attribute/Measure Alternative A: No Action

Alternative B: Extend a 

Determination of 

Nonregulated Status

Meets Purpose and Need 

and Objectives No Yes

Unlikely to pose a plant 

pest risk

Satisfied through use of 

regulated field trials

Satisfied – risk assessment

(USDA-APHIS, 2011b)

Management Practices

Acreage and Areas of 

Corn Production

Unchanged Unchanged

Agronomic Practices

Unchanged Unchanged

Pesticide Use

Unchanged Unchanged

Corn Seed Production Unchanged Unchanged

Organic Corn Production Unchanged Unchanged

Environment

Land Use Unchanged Unchanged

Water Resources Unchanged Unchanged

Soil Quality Unchanged Unchanged

Air Quality Unchanged Unchanged

Climate Change Unchanged Unchanged

Animal Communities

Unchanged Unchanged
61

Table 6. Summary of issues of potential impacts and consequences of alternatives 

(continued).

Attribute/Measure Alternative A: No Action

Alternative B: Extend a 

Determination of 

Nonregulated Status

Plant Communities Unchanged Unchanged

Gene Movement

Unchanged Unchanged

Soil Microorganisms

Unchanged Unchanged

Biological Diversity

Unchanged Unchanged

Human and Animal Health

Risk to Human Health Unchanged Unchanged

Risk to Animal Feed

Unchanged Unchanged

Socioeconomic 

Domestic Economic 

Environment

Unchanged Unchanged 

Trade Economic 

Environment

Unchanged Unchanged

Other Regulatory Approvals

U.S.

Unchanged for existing 

nonregulated GE organisms

FDA consultation pending

Other countries Unchanged Canada

Compliance with Other Laws

CWA, CAA, Eos 

Fully compliant Fully compliant
62

4 ENVIRONMENTAL CONSEQUENCES

4.1 Scope of Analysis 

Potential environmental impacts from the No Action Alternative and the Preferred Alternative 

for Maize Line HCEM485 corn are described in detail throughout this section. An impact would 

be any change, positive or negative, from the existing (baseline) conditions of the affected 

environment (described for each resource area in Section 2.0, Affected Environment). Impacts 

may be categorized as direct, indirect, or cumulative. A direct impact is an effect that results 

solely from a proposed action without intermediate steps or processes. Examples include soil 

disturbance, air emissions, and water use. An indirect impact may be an effect that is related to 

but removed from a proposed action by an intermediate step or process. Examples include 

surface water quality changes resulting from soil erosion due to increased tillage, and worker 

safety impacts resulting from an increase in herbicide use. 

A cumulative effects analysis is also included for each environmental issue. A cumulative 

impact may be an effect on the environment which results from the incremental impact of the 

proposed action when added to other past, present, and reasonably foreseeable future actions. 

An example includes breeding Maize Line HCEM485 with other nonregulated events. If there 

are no direct or indirect impacts identified for a resource area, then there can be no cumulative 

impacts. Cumulative impacts are discussed in Section 5.

Where it is not possible to quantify impacts, APHIS provides a qualitative assessment of 

potential impacts. Certain aspects of this product and its cultivation may be no different between 

the alternatives; those are described below. 

APHIS considered the potential for Maize Line HCEM485 to extend the range of corn 

production and affect the conversion of land to agricultural purposes. Stine’s studies 

demonstrate Maize Line HCEM485 is similar in its growth habit, agronomic properties, 

disease susceptibility, and composition to its antecedent GA21, its control group cultivars, 

other nonregulated varieties of glyphosate-resistant corn, and other GE and non-GE corn 

(Stine, 2011; USDA-APHIS, 2011b). As such, its cultural requirements would be no 

different than those of other corn or provided by the areas in which corn is currently 

cultivated. As presented in Subsection 2.1.1, Acreage and Area of Corn Production, the 

majority of corn cultivated in the U.S. is herbicide-resistant, most of which is glyphosateresistant (Duke and Powles, 2009; USDA-ERS, 2011a). Nonregulated Maize Line 

HCEM485 could replace other commercially available glyphosate-resistant corn varieties 

without requiring cultivation of new, natural lands. As such, land use changes associated 

with extending a determination of nonregulated status to Maize Line HCEM485 are not 

expected to be any different than those associated with the cultivation of other corn 

cultivars. Accordingly, although the preferred alternative would allow for new plantings of 

Maize Line HCEM485 to occur anywhere in the U.S., APHIS will focus the environmental 

analysis to those areas that currently support corn production. To determine areas of corn

production, APHIS consulted the NASS Census of Agriculture crop statistics to identify corn

producing states in the U.S.; all states except Alaska produce corn (USDA-NASS, 2009a). 

Additionally, winter nurseries for maize seed are found in the territory of Puerto Rico.
63

The environmental consequences of the different alternatives described above will be analyzed

under the assumption that farmers, who produce conventional corn, Maize Line HCEM485, or 

produce corn using organic methods, are using reasonable, commonly accepted BMPs for their 

chosen system and varieties during agricultural corn production. However, APHIS recognizes 

that not all farmers follow these BMPs for corn. Thus, the analyses of potential environmental 

affects will also include the assumption that some farmers do not follow these BMPs. Stine has 

indicated there is no need to change the use pattern of glyphosate for the glyphosate-resistant

Maize Line HCEM485 variety; hence, APHIS will use current glyphosate labels as the basis for 

its potential effects analysis.

4.2 Agricultural Production of Corn

4.2.1 Acreage and Area of Corn Production

No Action Alternative: Acreage and Area of Corn Production

Under the No Action Alternative, the total acres used for the production of corn in the U.S. is 

predicted to remain between 90 and 92 million acres through 2020 (USDA-OCE, 2011) (see 

Subsection 2.1.1, Acreage and Area of Corn Production). 

Both GE and non-GE varieties of corn would be produced under this alternative. The adoption 

of GE hybrids are likely to dominate U.S. corn production because GE hybrids comprised 88% 

of the planted corn acres in 2011 (USDA-ERS, 2011a), the bulk of which contain multiple 

(stacked) traits such as insect resistance (Bt) and herbicide resistance (see Subsection 2.1.1, 

Acreage and Area of Corn Production, Figure 3,) (Fernandez-Cornejo and Caswell, 2006; 

USDA-ERS, 2011a). From 2007 to 2011, the production of herbicide-resistant-only varieties 

leveled off at about 23%, insect-resistant-only varieties declined to 16% of all planted corn, 

while those varieties with stacked traits (with both insect and herbicide resistance) have

continued to increase to 49% of all planted corn acreage in 2011 (USDA-ERS, 2011a) (see 

Subsection 2.1.1, Acreage and Area of Corn Production, Figure 3). 

Preferred Alternative: Acreage and Area of Corn Production

An extension of a determination of nonregulated status to Maize Line HCEM485 under the 

Preferred Alternative would allow the planting and movement of Maize Line HCEM485 without 

APHIS-acknowledged notification. Maize Line HCEM485 is the same with regard to its growth 

habit and agronomic properties, disease susceptibility, and composition as its control cultivars, 

its antecedent GA21, other nonregulated varieties of glyphosate-resistant corn, and other GE and 

non-GE corn (Stine, 2011; USDA-APHIS, 2011b). Because it is similar to varieties that are 

currently available, Maize Line HCEM485 is expected to replace some of the currently available 

glyphosate-resistant varieties. Therefore the Preferred Alternative would not change corn 

production area and acreage when compared to the No Action Alternative. 

4.2.2 Agronomic Practices

No Acton Alternative: Agronomic Practices

As discussed in Subsection 2.1.2, Agronomic Practices, the cultivation of corn requires certain 

agronomic considerations such as soil and moisture regimes, planting schedules and rates, 

harvesting schedules, rotation strategy, tillage, and agricultural inputs. Planting schedules and 
64

rates are determined by factors such as regional climate, soil conditions, seed germination, 

anticipated pest problems, and weather (Farnham, 2001a). Similarly, the determination of the 

best harvest time is influenced by factors such as the price of corn, potential yield, weather, 

length of harvest period, and equipment and labor availability and cost (Bitzer et al., No Date). 

Crop rotations and tillage strategy would be accomplished in order to optimize soil nutrition, 

fertility and moisture, and control weeds, insects, and pests. 

The cultivation of corn requires several agricultural inputs such as irrigation, fertilizer (e.g., 

synthetic fertilizers, manures, and composts containing nitrogen, phosphorus, and potassium), 

pesticides (e.g., insecticides, herbicides), and fungicides (Olson and Sander, 1988; Hoeft et al., 

2000; McLeod and Studebaker, 2006). As discussed in Subsection 2.1.2, Agronomic Practices, 

these inputs are dependent on such factors as the region, climate, soil conditions, and pests 

present. Grower decisions regarding the type and extent of agricultural inputs needed to produce 

conventional or organic corn would continue to be based on the ease and flexibility of production 

systems and individual needs that may vary from year to year, responding to variation in 

weather, weed, insect pest, disease pressures, and targeted production returns (USDA-ERS, 

1997c). 

Weeds are the most important pests that interfere with yield and profitability (Gibson et al., 

2005; Baucom and Holt, 2009). Practices to reduce the incidence of weeds include tillage, crop 

rotation, intercropping, the use of ground covers and mulches, flame weeding, and the 

application of herbicides (Gunsolus, 2006; Hedtke et al., 2006; Smith and Scott, 2006; 

CropsReview, 2011; USDA-NASS, 2011c). In addition, no-till practices also reduce weed 

occurrence by minimizing soil disturbance that promotes weed seed germination (University of 

California, 2009). 

Due to the potential damage caused to crops from mechanical weed control and the availability 

of better herbicide technology, producers have turned more to chemical control in corn 

production (Smith and Scott, 2006). The proportion of herbicide-resistant corn cultivars in the 

U.S. has steadily grown since the approval of the request for nonregulated status of the first 

variety of herbicide-resistant corn in 1995 (USDA-APHIS, 2012). Recent estimates indicate the 

majority of corn planted in the U.S. is herbicide resistant, comprising 72% of corn planted in 

2011 (USDA-ERS, 2011a), and most herbicide-resistant corn is glyphosate-resistant (Duke and 

Powles, 2009). The increased use of glyphosate as a consequence of expanded adoption of the 

glyphosate-resistant trait in corn production is primarily attributed to the herbicide’s effective 

and efficient weed control as a non-selective herbicide (Owen et al., 2011), its lower cost and 

simplicity of use, its minimal toxicity to animals and the environment, and its support of 

conservation tillage practices (Duke and Powles, 2009; NRC, 2010; Green and Owen, 2011).

Another observed herbicide trend since the adoption of GE corn has been a substantial reduction 

in the diversity of herbicides used in corn production (Young, 2006). The use of other herbicides 

has declined significantly, and it is estimated that 34% of corn acres receive only glyphosate for 

weed management (NRC, 2010; Owen, 2011). 

In 2010, over 98% of corn acres in 19 survey states were treated with herbicides, and of that 

acreage, 66% were treated with glyphosate (USDA-NASS, 2011c). Farmers have recently begun 

to broaden weed management strategies in response to the development of herbicide-resistant 

weeds, addressed in Subsection 2.3.2, Plants Communities. 
65

Preferred Alternative: Agronomic Practices

The continued use of herbicides, including glyphosate, would be unaffected by the extension of a 

determination of nonregulated status to Maize Line HCEM485. Like under the No Action 

Alternative, the amount of herbicides other than glyphosate applied to corn would likely continue 

to decline as it has for the last decade (NRC, 2010). The use rate of glyphosate and other 

herbicides is not expected to change as a result of extending a determination of nonregulated 

status to Maize Line HCEM485, because Maize Line HCEM485 is anticipated to replace other 

glyphosate-resistant corn cultivars, and no change in the registered use of glyphosate is 

proposed. In the longer term, like under the No Action Alternative, the use of non-glyphosate

herbicides may increase and more emphasis may be placed on best management agronomic 

practices to address the issue of glyphosate-resistant weeds (Green, 2011; Owen, 2011; Owen et 

al., 2011); (see Subsection 4.4.2, Plants Communities). Glyphosate would likely continue to be a 

major component of weed management in corn production because of its flexibility in 

application, its efficacy against a broad spectrum of weeds, and its relatively low cost (Powles, 

2008; Duke and Powles, 2009; Green and Owen, 2011; Owen et al., 2011). No changes in 

agronomic practices would occur as a consequence of extending a determination of nonregulated 

status to Maize Line HCEM485 when compared to the No Action Alternative.

4.2.3 Corn Seed Production

No Acton Alternative: Corn Seed Production

Commercially available corn seed is produced in those regions of the U.S. where the specific 

hybrid is best adapted for growth, as well as in winter nurseries in Hawaii, Puerto Rico, Chile, 

and Argentina (see Subsection 2.1.3, Corn Seed Production). Corn is a major U.S. crop, and 

planted acreage in USDA projections is expected to remain at current levels to 2020 (USDAOCE, 2011); therefore, seed production is likely to remain at current levels. Because 72% of the 

corn acreage is planted in herbicide-resistant varieties, a comparable amount of the corn seed 

acreage planted is likely to be of herbicide-resistant varieties. 

Corn seed production adheres to seed certification standards such as land history, field isolation, 

and varietal purity, as discussed in Subsection 2.1.3, Corn Seed Production, to ensure the quality 

of corn seed remains high. Corn producers implement measures to preserve the identity of their 

seed varieties in accordance with seed certifying standards. 

Preferred Alternative: Corn Seed Production

Stine’s field trials have not demonstrated any agronomic or phenotypic differences between 

Maize Line HCEM485 and its control corn cultivars (Stine, 2011; USDA-APHIS, 2011b). As 

described in Subsection 4.2.1, Acreage and Area of Corn Production, an extension of a 

determination of nonregulated status to Maize Line HCEM485 would likely replace some of the 

acreage planted in other commercially available glyphosate-resistant corn cultivars on current 

production acres because of its similarity to these other cultivars. The extent to which Maize 

Line HCEM485 is planted for seed is dependent upon how much it is adopted in the market, but 

it would likely replace acres planted to other glyphosate-resistant varieties. 
66

4.2.4 Organic Corn Production

No Action Alternative: Organic Corn Production

Acreage devoted to organic corn production is small relative to that of GE varieties. Measurable 

acreages of organic corn is produced in 39 states, with the largest amount produced in Iowa, 

Michigan, Minnesota, New York, and Wisconsin, which also produced a combined amount of 

about 29 million acres of non-organic conventional and GE corn in 2010 (USDA-NASS, 2010a; 

USDA-ERS, 2011a; USDA-NASS, 2011b). While the amount of organic corn production has 

steadily increased between 1995 and 2008, the latest year with available statistics, organic corn 

production remained at around 0.2% of the total U.S. corn acreage from 2005 through 2008 

(USDA-ERS, 2010a). 

It is important to note that the current NOP regulations do not specify an acceptable threshold 

level for the adventitious presence of GE materials in an organic-labeled product. The 

unintentional presence of the products of excluded methods will not affect the status of an 

organic product or operation when the operation has not used excluded methods and has taken 

reasonable steps to avoid contact with the products of excluded methods as detailed in their 

approved organic system plan (Ronald and Fouche, 2006; USDA-AMS, 2008). However, 

certain markets or contracts may have defined thresholds (Non-GMO-Project, 2010). Under the 

No Action Alternative, 88% of the corn grown in the U.S. is GE. Growers with contracts that 

specify defined thresholds for GE materials incorporate production practices to meet their 

thresholds. 

Preferred Alternative: Organic Corn Production

As described in Subsection 4.2.1, Acreage and Area of Corn Production, extending a 

determination of nonregulated status to Maize Line HCEM485 is not expected to change the 

acreage or area of corn production that could potentially impact organic corn production. 

Because of its similarity to other corn growth and reproductive habits, the current availability 

and extent of other nonregulated glyphosate-resistant corn, and the relative stability of acreage 

devoted to herbicide-resistant-only corn production in the U.S., Maize Line HCEM485 is 

expected to replace other glyphosate-resistant corn in the areas that corn is currently produced. 

Maize Line HCEM485 would not influence the overall adoption rate of herbicide-resistant corn. 

Extension of a determination of nonregulated status to Maize Line HCEM485 under the 

Preferred Alternative would not change agronomic production practices used by organic or other 

corn producers. There are no discernible differences in pollen size and morphology between 

Maize Line HCEM485 and control corn comparators, and, while Maize Line HCEM485 pollen 

viability was significantly greater than the control, it was within the ranges reported for other 

corn reference samples (Stine, 2011; USDA-APHIS, 2011b). As such, an organic corn producer 

may utilize existing separation practices as used for all other commercially available glyphosateresistant corn varieties to meet National Organic Standards and NOP eligibility. 

The production of organic corn would not be expected to change under the Preferred Alternative; 

hence, the potential impacts of extending a determination of nonregulated status to Maize Line 

HCEM485 would be similar to the No Action Alternative. 
67

4.3 Physical Environment

4.3.1 Soil Quality 

No Action Alternative: Soil Quality

Agronomic practices associated with GE and non-GE corn crop production that benefit soil 

quality include contouring, use of cover crops to limit the time soil is exposed to wind and rain 

and introduce certain soil nutrients, crop rotation, and windbreaks. Other agronomic practices 

utilized in non-GE and GE corn production that potentially impact soil quality include tillage for 

crop establishment, fertilizer, weed control, and pesticide application.

The production of nonregulated herbicide-resistant corn utilizes EPA-registered pesticides for 

insect and plant pest management, including glyphosate. In 2010, herbicides were applied to 

98% of cropland planted to corn (USDA-NASS, 2011c). Pesticides (including herbicide, 

insecticide, and fungicide) consist of active ingredients that control pests and inert ingredients to 

facilitate their application. In 2010, 66% of all active ingredients applied to corn treated with

pesticides were herbicidal (USDA-NASS, 2011c), indicating their widespread use and potential 

to affect the environment The amount of herbicides other than glyphosate applied to corn has

declined over the last decade (NRC, 2010) (see Subsection 4.2.2, Agronomic Practices). The 

environmental risks of pesticide use are assessed by the EPA in the pesticide registration process 

and are regularly re-evaluated by the EPA to maintain their registered status under FIFRA. In 

this process, steps to reduce pesticide residuals and persistence in soil are included on a 

pesticide’s label and approved by the EPA. 

As discussed in Subsection 2.2.1, Soil Quality, there have been several reports of the long-term 

use of glyphosate immobilizing manganese and potentially reducing plant uptake or ability to 

utilize this nutrient (Eker et al., 2006; Neumann et al., 2006; Ozturk et al., 2008; Cakmak et al., 

2009; Huber, 2010). Additional investigations are required to determine the scope and 

characterization of glyphosate interactions with nutrients. The current understanding is 

manganese-glyphosate interaction resulting in manganese problems appears to occur in areas 

where manganese deficiency already exists (Hartzler, 2010), and producers should be prepared to 

address it with agronomic practices designed to augment manganese (Camberato et al., 2010).

The development of glyphosate-resistant weeds or weed management tillage practices potentially 

impact soil quality. A variety of strategies should be utilized in addressing glyphosate-resistant

weeds, including applying the right strength of herbicide, rotating herbicide modes of action, 

crop rotation, spot treatments, vigilant scouting, and hand weeding (Gunsolus, 2002; Sellers et 

al., 2011). In the long term, more diverse weed management tactics potentially including more 

aggressive tillage practices that can affect soil quality may be needed to address the increasing 

emergence of glyphosate-resistant weeds (Beckie, 2006; Owen, 2011; Owen et al., 2011). The 

particular mix of weed management tactics selected by an individual producer is dependent upon 

many factors, including the agroecological setting, the problem weed type, and agronomic and 

socioeconomic factors important to farmers (Beckie, 2006).

Preferred Alternative: Soil Quality

Extending a determination of nonregulated status to Maize Line HCEM485 would not affect soil 

quality. With nonregulated status, Maize Line HCEM485 would likely replace other 
68

commercially available glyphosate-resistant corn cultivars because most corn acreage is 

currently planted to either glyphosate-resistant-only corn or herbicide-resistant corn varieties 

stacked with other GE traits (Duke and Powles, 2009; USDA-ERS, 2011a). The area and 

acreage of corn production potentially impacting soil quality would not change as a result of the 

Preferred Alternative. 

Maize Line HCEM485 is agronomically and compositionally equivalent to its antecedent GA21, 

its control cultivars, and other GE and non-GE corn varieties currently in commercial production 

(Stine, 2011; USDA-APHIS, 2011b). Agronomic practices such as tillage and the application of 

agricultural chemicals that could impact soil quality or its community structure and function 

would not change from those currently used for production of other nonregulated glyphosateresistant corn varieties. 

Since it is expected to replace other glyphosate-resistant cultivars, the nonregulated status of 

Maize Line HCEM485 would not affect weed management practices or their effects on soil 

quality. As discussed above, more diverse weed management tactics potentially including more 

aggressive tillage practices that can affect soil quality may be needed to address the increasing 

emergence of glyphosate-resistant weeds (Beckie, 2006; Owen, 2011; Owen et al., 2011). As 

described under the No Action Alternative discussion, the weed management tactics selected by 

an individual producer would be dependent upon many factors (Beckie, 2006). Weed 

management practices needed for the production of Maize Line HCEM485 would be no different 

than those used in other commercially available glyphosate-resistant corn cultivars. 

Under the Preferred Alternative, the amount of herbicides other than glyphosate applied to corn 

would likely continue to decline as they have for the last decade (NRC, 2010) (see Subsection 

4.2.2, Agronomic Practices). The application of glyphosate is not expected to change as a result 

of extending a determination of nonregulated status to Maize Line HCEM485, as no change in 

the registered use or label of this herbicide is proposed and, as discussed in Subsection 4.2.1, 

Acreage and Area of Corn Production, the cultivar is anticipated to replace other glyphosateresistant corn varieties. As discussed above, the impact of glyphosate on manganese availability 

for uptake by crops after its application is an issue that may be addressed with common practices 

utilized to augment deficient soil nutrients. Since Maize Line HCEM485 is agronomically 

similar to other GE and non-GE corn varieties and would most likely replace other glyphosateresistant varieties, the same methods used to address manganese deficiency in current corn 

production would also be used with Maize Line HCEM485; therefore, impacts to soil quality 

under the Preferred Alternative would be the same as the No Action Alternative. 

4.3.2 Water Resources

No Action Alternative: Water Resources

As discussed in Subsection 4.2.1, Acreage and Area of Corn Production, corn is expected to 

continue to be a major crop in the U.S., with a predicted increase in production from 

approximately 88 million acres of land in 2010 to between 90 and 92 million acres through 2020 

(USDA-OCE, 2011). Current agronomic practices associated with corn production that have 

potential to impact water quality or quantity include tillage, agricultural inputs such as fertilizer 

and pesticide use, and irrigation. The majority of herbicide-resistant corn grown in the U.S. is 

glyphosate-resistant (Duke and Powles, 2009). 
69

As discussed above in Subsection 4.3.1, Soil Quality, more diverse weed management tactics 

potentially including more aggressive tillage practices that can affect soil erosion may be needed 

to address the increasing emergence of glyphosate-resistant weeds (Beckie, 2006; Owen, 2011; 

Owen et al., 2011). Increased tillage could result in more soil erosion that could consequently 

increase sedimentation and residual pollutant loading of nearby waters. The particular mix of 

weed management tactics selected by an individual producer, however, are dependent upon 

many factors such as the agroecological setting, the problem weed type, and agronomic and 

socioeconomic factors important to farmers (Beckie, 2006). As discussed in Subsection 2.2.2, 

Water Resources, fertilizer and pesticide use has the potential to impact water quality. In 2010, 

fertilizer (primarily nitrogen) was applied to the majority of corn acres, and herbicides applied to 

98% of planted corn (USDA-NASS, 2011c). Of the treated acres, glyphosate was the most 

commonly applied herbicide active ingredient that year (USDA-NASS, 2011c). When used 

consistent with registered uses and EPA-approved labels, glyphosate presents minimal risk to 

surface and groundwater. Irrigation from surface and subsurface sources can reduce water 

quantity and impact water quality by the used water acquiring increased sediment, nutrients, and 

chemicals adsorbed to soil that is subsequently leached to groundwater, or returned to surface 

water. Recent estimates indicate only 11.0 to 11.5% of corn acreage is irrigated in the U.S.

(NCGA, 2011). 

Preferred Alternative: Water Resources 

An extension of a determination of nonregulated status to Maize Line HCEM485 under the 

Preferred Alternative would present another glyphosate-resistant corn and weed management 

option to farmers. It is expected Maize Line HCEM485 would replace other glyphosate-resistant 

corn varieties and, therefore, not change the overall acreage or area of corn production in the 

U.S. that potentially impacts water resources through sedimentation and residual pollutant 

loading from runoff. As discussed in Subsection 4.2.1, Acreage and Area of Corn Production, 

herbicide-resistant corn comprised 72% of all planted corn acreage in 2011 and the majority of 

herbicide-resistant corn is glyphosate resistant (Duke and Powles, 2009; USDA-ERS, 2011a). 

As Maize Line HCEM485 is similar in its growth and agronomic characteristics to its control 

cultivars and antecedent GA21, and other nonregulated glyphosate-resistant maize lines (USDAAPHIS, 2011b), no changes to irrigation and other agronomic practices such as fertilizer and 

pesticide applications, including herbicides, that have the potential to affect water quality or 

quantity, would occur as a result of this alternative. 

Since Maize Line HCEM485 is expected to replace other glyphosate-resistant corn acreage, its 

nonregulated status would not affect the recent trend to broaden weed management practices, 

including more tillage that may increase erosion, and thereby sediment loading to surface waters. 

The impacts of the Preferred Alternative to water resources, therefore, would be the same as the 

No Action Alternative. 

4.3.3 Air Quality

No Action: Air Quality 

Corn is the most widely produced feed grain in the U.S., so its production practices can 

substantially impact air quality. Tillage is utilized to prepare the ground for planting, to control 

weeds, incorporate nutrients and herbicides into soil, and is useful for other functions such as 
70

controlling water flow through a field (see Subsection 2.1.2, Agronomic Practices). Tillage 

exposes soil to wind erosion and utilizes motorized equipment that produces emissions. The use 

of herbicide-resistant crops has facilitated the adoption of conservation tillage (Towery and 

Werblow, 2010). The USDA reports that in 2010, up to 74.5% of planted corn acres were 

produced under conservation tillage practices ranging from no-till to reduced till (USDA-ERS, 

2011f). Reduced tillage generates fewer particulates (dust) and potentially contributes to lower 

rates of wind erosion releasing soil particulates into the air, benefitting air quality (Fawcett and 

Towery, 2002). Conservation tillage also reduces equipment emissions due to decreased usage. 

More recently, these benefits may be eroding by employing more aggressive tillage to control the 

increasing resistance of weeds to herbicides, including glyphosate-resistant weeds (Beckie, 2006; 

Owen, 2011; Owen et al., 2011). Weed management methods, however, vary from farm to farm, 

dependent upon the agroecological setting, the problem weed type, and agronomic and 

socioeconomic factors important to farmers (Beckie, 2006).

Pesticide application in corn production has the potential to impact air quality while actively 

applied through spray drift, afterward by volatilization off of plant and soil surfaces, and by 

windborne soil containing residuals in areas where a pesticide has been dispensed (see 

Subsection 2.2.3, Air Quality, for detailed discussion). Glyphosate is the most common 

herbicide active ingredient applied to herbicide-treated corn in the U.S. (USDA-NASS, 2011c). 

The EPA is currently evaluating new regulations for pesticide drift labeling and the identification 

of BMPs to control such drift (US-EPA, 2009d), as well as identifying scientific issues 

surrounding field volatility of conventional pesticides (US-EPA, 2010). Agricultural production 

of existing nonregulated GE and conventional corn utilize EPA-registered pesticides for insect 

and plant pest management, including glyphosate. Glyphosate has a low vapor pressure and 

volatility from soils (US-EPA, 1993b). Glyphosate’s EPA-approved label provides measures for 

minimizing the potential air quality impacts from its use. When used in accordance with 

registered uses and EPA-approved labels, glyphosate poses minimal risks to air quality. 

Increasing or decreasing the amount of corn production acreage and its associated agronomic 

practices with emissions potentially impact air quality. As discussed in Subsection 4.2.1, 

Acreage and Area of Corn Production, corn is a major crop in the U.S., expected to maintain 

current production levels through 2020 (USDA-OCE, 2011). Global market forces determine the 

price of corn, which in turn affects grower decisions on how much to plant (USDA-OCE, 2011). 

Preferred Alternative: Air Quality

Maize Line HCEM485 is agronomically and compositionally equivalent to its antecedent GA21, 

its control cultivars, and other GE and conventional corn varieties currently in commercial 

production (Stine, 2011; USDA-APHIS, 2011b). No changes to agronomic practices that are 

sources of emissions or positively contribute to air quality such as the amount, type and timing of 

tillage, equipment use, irrigation, and the application of fertilizers or pesticides would result from

extending a determination of nonregulated status to Maize Line HCEM485 under the preferred 

alternative. The commercial use of glyphosate is expected to remain the same if Maize Line 

HCEM485 were determined nonregulated, since the cultivar would replace other glyphosateresistant corn varieties, and no changes to glyphosate’s registered use or label are proposed. 

Approximately 72% of planted corn in the U.S. is herbicide resistant, and of that, most is 

glyphosate resistant (Duke and Powles, 2009; USDA-ERS, 2011a) (see Subsection 4.2.1, 

Acreage and Area of Corn Production, for detailed discussion). 
71

Maize Line HCEM485 would not likely change the development of glyphosate-resistant weeds 

or the methods used for their control that may impact air quality, since it is expected to replace 

other glyphosate-resistant corn cultivars. In summary, there are no new impacts to air quality 

posed by an extension of determination of nonregulated status to Maize Line HCEM485. The 

potential impacts to air quality under the Preferred Alternative are, therefore, similar to the No 

Action Alternative.

4.3.4 Climate Change

No Action Alternative: Climate Change

The major sources of GHG emissions associated with crop production are soil N2O emissions, 

soil CO2 and CH4 fluxes, and CO2 emissions associated with agricultural inputs and farm 

equipment operation (US-EPA, 2011c). Agricultural practices that produce CO2 emissions 

include liming and the application of urea (i.e., nitrogen) fertilization to agricultural soils, and 

CH4 produced by enteric fermentation and animal manure management. Agricultural soil 

management activities including fertilizer application and cropping practices are the largest 

source of N2O emissions in the U.S. (US-EPA, 2011c). Corn crop production primarily affects 

climate-changing emissions through: (1) fossil fuel burning equipment used for production and 

nitrogen fertilization producing CO2; and, (2) cropping production practices including residue 

management and tillage (see Subsection 2.2.4, Climate Change, for detailed discussion). 

Conservation tillage practices increase crop residue on the surface, promoting the production of 

SOC and protecting the soil from erosive forces that would release SOC back to the air. These 

practices also reduce the use of emissions-producing equipment normally used in tilling. The 

USDA has estimated approximately 74.5% of planted corn acres in 2010 were produced under 

conservation tillage practices ranging from no-till to reduced till (USDA-ERS, 2011f). Recent 

increases in the incidence of herbicide-resistant weeds, including glyphosate, may require 

increased tillage to affect control (Beckie, 2006; Owen, 2011; Owen et al., 2011). This could 

potentially release more SOC sequestered in upper soil layers; however, the particular weed 

management methods employed by individual farmers would be dependent on many factors 

unique to characteristics of the individual farm, including its agroecological setting, the 

particular problem weed type, and on-farm economics (Beckie, 2006).

Nitrogen is also the most-used fertilizer in U.S. corn production (USDA-NASS, 2011c). 

Nitrogen in the form of urea is commonly applied to cornfields and contributes CO2 emissions 

from the volatilization of ammonia. Recommended BMPs to reduce volatilization include 

incorporating urea with equipment, accompanied with irrigation or rainfall; topdressing urea 

when temperatures and soil moisture levels are low; and avoiding topdressing urea in higher risk 

conditions, except if there is an opportunity to incorporate the urea within a few days of 

application (Jones et al., 2007).

Preferred Alternative: Climate Change

Because Maize Line HCEM485 is similar to other GE and non-GE corn cultivars in terms of its 

growth habit, agronomic properties, disease susceptibility, and composition (USDA-APHIS, 

2011b), the agronomic practices required to cultivate Maize Line HCEM485 would be no 

different than those utilized in the production of other herbicide-resistant corn cultivars. 
72

Therefore, no changes to agricultural practices that could affect GHG emissions would be 

expected from extending a determination of nonregulated status to Maize Line HCEM485. 

Because Maize Line HCEM485 is another glyphosate-resistant cultivar similar to other

commercially available glyphosate-resistant corn varieties, and the majority of planted corn in 

the U.S. is herbicide resistant (72% in 2011) primarily consisting of glyphosate-resistant 

cultivars (Duke and Powles, 2009; USDA-ERS, 2011a), Maize Line HCEM485 would likely 

replace other glyphosate-resistant cultivars rather than expand the production of glyphosateresistant cultivars. An extension of a determination of nonregulated status to Maize Line 

HCEM485 would not likely change the development of glyphosate-resistant weeds, since it is 

expected to replace other glyphosate-resistant maize acreage; thus, no change to GHG emissions 

would occur from use of fossil fuels, release of SOC, or carbon sequestration in plant residue and 

soils under the Preferred Alternative. As discussed under the No Action Alternative above, more 

diverse weed management tactics, potentially those including more aggressive tillage practices 

that can affect GHG emissions, may be needed in the long term to address the increasing 

emergence of glyphosate-resistant weeds (Beckie, 2006; Owen, 2011; Owen et al., 2011). Since 

Maize Line HCEM485 is expected to replace other glyphosate-resistant cultivars, its 

nonregulated status would not alter weed management practices and their effects on GHG 

contributing to climate change; therefore, the potential impacts to climate change under the 

Preferred Alternative would be similar to the No Action Alternative.

4.4 Biological Resources

4.4.1 Animal Communities

No Action Alternative: Animal Communities

Corn production potentially impacts animal communities through the conversion of wildlife 

habitat to agricultural purposes. As discussed in Subsection 2.2., Acreage and Area of Corn 

Production, corn was produced on approximately 92.3 million acres in 2011, an increase of 

approximately 4.1 million acres over 2010 (USDA-NASS, 2011b). Corn is expected to continue 

to be a major crop in the U.S. through 2020 (USDA-OCE, 2011). A wide array of wildlife 

occupy and/or utilize habitats that are within or adjacent to cornfields (see Subsection 2.3.1, 

Animal Communities). While cornfields are less suitable for wildlife than adjacent pasture, 

fallow fields, windbreaks, or shelterbelts, those in conservation tillage management provide 

greater benefit for wildlife than those in more intensive tillage. This is because greater diversity 

in plants would occur that provides more habitat and potential food sources, soil would be less 

disturbed, and potentially sediment and agricultural pollutant loading of nearby surface waters 

would be reduced, improving water quality (Brady, 2007; Sharpe, 2010).

Glyphosate-resistant corn varieties have been nonregulated since 1997 (USDA-APHIS, 2012), 

and the majority of corn cultivated today is herbicide resistant (USDA-ERS, 2011a), primarily 

glyphosate-resistant (Duke and Powles, 2009). All glyphosate-resistant corn varieties currently 

available on the market have been evaluated for their food and feed safety impacts by the FDA. 

The EPSPS protein that confers glyphosate resistance in GA21 (the antecedent of Maize Line 

HCEM485) is corn-derived, and 99.3% identical to its non-herbicide-resistant corn comparators 

(Monsanto, 1997). It has been previously evaluated by the FDA;according to the consultation 

note, 
73

“Monsanto has concluded that corn containing transformation event 

GA21 is not materially different in composition, nutrition, and 

safety from corn currently grown, processed, marketed, and 

consumed for animal feed or human food. At this time, based on 

Monsanto's description of its data and analyses, the Agency 

considers Monsanto's consultation on corn from varieties containing 

transformation event GA21 to be complete.”

(US-FDA, 1998a). Consumption of nonregulated glyphosate-resistant corn presents minimal 

risk to animal communities.

Current corn agronomic practices potentially impacting animal communities include application 

of agricultural inputs, such as fertilizer, herbicides, and pesticides. Both fertilizer and pesticides 

are applied to the majority of corn acres in the U.S. (USDA-NASS, 2011c) and potentially 

impact non-target wildlife from ingestion or spray drift. Glyphosate is the primary herbicide 

applied to herbicide-treated corn acreage in the U.S. (USDA-NASS, 2011c). As discussed in 

Subsection 2.1.2, Agronomic Practices, there are several glyphosate formulations (US-EPA, 

2009b) that differ in the timing and amount of application to field corn. The environmental risks 

of glyphosate herbicides are assessed by the EPA in the pesticide registration process. The 

glyphosate RED was last accomplished in 1993, and the herbicide is currently undergoing 

registration review scheduled for the final decision in 2015 (US-EPA, 2009a). As discussed in 

Subsection 2.3.1, Animal Communities, the registered uses for glyphosate pose minimal risk to 

animals, but spray drift may adversely impact non-target plants that provide habitat. The EPA is 

evaluating new regulations for labeling and BMPs to control drift (US-EPA, 2009d). When used 

consistent with the EPA-registered uses and labels, glyphosate application in corn presents 

minimal risk to animal communities. In 2010, 66% of all active ingredients applied to corn 

treated with pesticides were herbicidal (USDA-NASS, 2011c).

More diverse weed management tactics potentially including more aggressive tillage practices 

that can affect animal communities may be needed to address the increasing emergence of 

glyphosate-resistant and other herbicide-resistant weeds (Beckie, 2006; Owen, 2011; Owen et 

al., 2011). As discussed above, more intensive tillage can reduce wildlife habitat and contribute 

to increased sedimentation and pollutants in runoff to nearby surface waters, affecting water 

quality that could impact wildlife. The particular mix of weed management tactics selected by 

an individual producer would be dependent upon many factors, including the agroecological 

setting, the problem weed type, and agronomic and socioeconomic factors important to farmers 

(Beckie, 2006). 

Preferred Alternative: Animal Communities

As part of the assessment for the proposed action, APHIS has evaluated the potential effects of 

each alternative on a wide array of wildlife species and their habitats occurring in the U.S. 

Under the Preferred Alternative, a determination of nonregulated status would be extended to

Maize Line HCEM485, and it would be available as another glyphosate-resistant corn and weed 

management option for farmers. As stated above, the majority of corn planted in the U.S. today 

is herbicide and glyphosate resistant (Duke and Powles, 2009; USDA-ERS, 2011a). As such, it 

is expected Maize Line HCEM485 as another option to other currently available glyphosateresistant corn varieties would replace these varieties and not change the acreage or area of corn 
74

production in the U.S. (see Subsection 4.2.1, Acreage and Areas of Corn Production). Maize 

Line HCEM485 is similar in its growth and agronomic characteristics to its control comparators, 

its antecedent GA21, and other nonregulated glyphosate-resistant corn lines (Stine, 2011; 

USDA-APHIS, 2011b); hence, no changes to agronomic practices such as cultivation, crop 

rotation, irrigation, tillage, or agricultural inputs with potential impacts to wildlife and their 

habitat would likely occur under this alternative. 

As discussed in Subsection 2.5, Animal Feed, a final food consultation with the FDA for Maize 

Line HCEM485 was submitted by Stine in December 2010 and is still pending. As discussed in 

the No Action Alternative, the food safety of the EPSPS protein conveying glyphosate resistance 

was previously established by an FDA evaluation. Because the composition of Maize Line 

HCEM485 is similar to its antecedent GA21 and other nonregulated glyphosate-resistant corn

lines (Stine, 2011), with no expected hazards associated with its consumption, the risk of Maize 

Line HCEM485 affecting wildlife species is also unlikely, regardless of exposure. 

Commercial use of glyphosate is not expected to change as a result of an extension of a 

determination of nonregulated status to Maize Line HCEM485. Based upon information 

provided by Stine (2011), Maize Line HCEM485 is similar in its growth characteristics to its 

antecedent GA21 and other nonregulated glyphosate-resistant corn. No changes to the registered 

uses or labels of glyphosate products would be required to apply it to Maize Line HCEM485. 

Consequently, there would be no difference in the potential of Maize Line HCEM485 cultivation 

to impact wildlife or habitat from that of other nonregulated glyphosate-resistant corn varieties. 

As discussed above, the EPA is currently evaluating new regulations for labeling and BMPs to 

control drift. When used consistent with the EPA-registered uses and labels, glyphosate 

application in Maize Line HCEM485 fields presents minimal risk to animal communities. 

An extension of a determination of nonregulated status to Maize Line HCEM485 would not 

change the development of glyphosate-resistant weeds or the methods used for their control that 

may impact animal communities, such as increased tillage. As discussed above, Maize Line 

HCEM485 would likely replace other glyphosate-resistant corn cultivars that currently comprise 

the majority of the 72% of corn acres planted with herbicide-resistant cultivars.

Based on the above, the impacts of extending a determination of nonregulated status to Maize 

Line HCEM485 to animal communities would be similar to those of the No Action Alternative.

4.4.2 Plants Communities

No Action Alternative: Plants Communities

The majority of U.S. corn acres are planted with GE herbicide-resistant corn cultivars. Plants 

communities are varied and adapted to local climate and soil, as well as the frequency of natural 

or human-induced disturbance (Smith and Smith, 2003). Non-crop vegetation in cornfields is 

limited by farmers’ cultivation and weed control practices. Plants communities adjacent to 

cornfields commonly include other crops, borders, hedgerows, windbreaks, pastures, and other 

natural vegetation. 

Agricultural practices affect plants communities by exerting selection pressures that influence 

the type and composition of plants present in a community. Preparation of fields for planting of 
75

crops removes other plants that compete for light and nutrients. Natural selection in frequently 

disturbed environments enables colonization by plants exhibiting early germination and rapid 

growth from seedling to sexual maturity, and the ability to reproduce sexually and asexually 

(Baucom and Holt, 2009). These weedy characteristics enable such plants to spread rapidly into 

areas undesired by humans.

Weeds are the most important pest in agriculture, competing for light, nutrients, and water and 

can significantly affect yields (Gibson et al., 2005; Baucom and Holt, 2009). Weeds commonly 

encountered in corn production include water hemp, giant ragweed, common lambsquarters, and 

others as described in Subsection 2.3.2, Plants Communities. Agronomic practices common in 

corn production, such as tillage and herbicide use, impart selection pressures on the weed 

community that can result in shifts in the relative importance of specific weeds (Owen, 2008). In 

aggressive tillage systems, weed diversity tends to decline and annual grasses and broadleaf 

plants are the dominant weeds; whereas, in no-till fields, greater diversity of annual and 

perennial weed species may occur (Baucom and Holt, 2009). The most common weed 

management tactic in U.S. corn production is to use herbicides. Recent estimates indicate 

herbicides are applied to 98% of planted corn acreage, and on that acreage, the most applied 

herbicide is glyphosate (USDA-NASS, 2011c). 

Herbicide resistance occurs when a plant survives the application of an herbicide and reproduces, 

passing on its resistance to new generations. Herbicide-resistant weeds can become 

agronomically important as they out-compete crops and require additional resources to affect 

control. As discussed in Subsection 2.3.2, Plants Communities, weed species resistant to 

glyphosate are becoming more agronomically important in crop production. For example, 

glyphosate-resistant Palmer pigweed (amaranth) is a major economic problem in the Southeast 

U.S. while glyphosate-resistant waterhemp is an economically important weed in Midwestern 

states (Culpepper et al., 2006; Owen, 2008). In response, producers are diversifying weed 

management tactics in corn production to include alternating crops resistant to different herbicide 

modes of action grown in a field, alternating the herbicide modes of action used, practicing more 

crop rotation, and increasing tillage to affect control of herbicide-resistant weeds (Owen et al., 

2011). Weeds are also developing resistance to multiple herbicides as well, but are also 

controlled with adjustments to practices such as crop rotation and tillage (Owen et al., 2011).

As discussed in Subsection 2.3.3, Gene Flow and Weediness, there are no extant populations of 

sexually compatible species related to Z. mays within the continental U.S., its territories, or 

possessions; therefore, APHIS (2011b) has concluded there is no significant risk of gene flow 

between cultivated corn and its weedy relatives that may impact plants communities.

Volunteer herbicide-resistant corn pose an additional management challenge when they appear in 

subsequent crops with the same resistance and can be extensive and problematic (see Subsection 

2.3.2, Plants Communities). Typical agronomic practices, however, are effective in the 

management of volunteer corn. Glyphosate-resistant volunteer corn is being controlled by the 

application of effective herbicides (e.g., ACCase and ALS inhibitors), mechanical means, and 

rotation of crops with resistance to different herbicide modes of action (Beckie and Owen, 2007; 

Zollinger et al., 2011). The incidence of glyphosate-resistant volunteer corn in cornfields where 

it was not planted the year before as a result of pollen-mediated gene flow can be controlled by 
76

maintaining adequate spatial or temporal isolation distances between corn crops. See Subsection 

2.3.3, Gene Flow and Weediness, for a description of pollen-mediated gene flow in corn.

The application of an herbicide in corn production has the potential to impact non-target plants 

communities through spray drift, volatilization (evaporation), its adsorption to soils incorporated 

in runoff, leaching, and cleaning and disposal of the equipment used to dispense it. The EPA is 

currently evaluating new regulations for pesticide drift labeling and the identification of BMPs to 

control such drift (US-EPA, 2009d), as well as identifying scientific issues surrounding field 

volatility of conventional pesticides (US-EPA, 2010). Glyphosate is currently under review by 

EPA for continued registration of the herbicide, with a reregistration decision expected in 2015 

(US-EPA, 2009a). Glyphosate is toxic to most terrestrial and aquatic plants, inducing plant 

death. The herbicide has low leaching potential, low vapor pressure, and low volatility from 

soils (US-EPA, 1993b; Senseman, 2007). In its 1993 glyphosate reregistration decision, the EPA 

required additional studies concerning vegetative vigor, droplet size spectrum, and a drift field 

evaluation that did not affect the reregistration eligibility of the herbicide (US-EPA, 1993a). The 

potential effects of glyphosate spray drift are minimized by EPA-approved labels that provide 

detailed measures to manage spray drift, including optimal wind conditions, temperature 

inversions, humidity, spray droplet size, sprayer boom heights, aerial spraying by aircraft 

measures, and inclusion of drift reduction additives (Monsanto, 2010). 

In summary, under the No Action Alternative, natural selection, and the selection pressure 

exerted through the use of herbicides and other agronomic practices, impact plants communities 

by either inducing plant death, selecting for weedy characteristics, inducing shifts in the 

composition of the plant community, through gene flow to other related plants, and in some 

cases, contributing to the development of herbicide-resistant weeds. 

Preferred Alternative: Plants Communities

Impacts of Maize Line HCEM485 to plants communities adjacent to or within agroecosystems 

would not be different from currently available glyphosate-resistant corn cultivars. As discussed 

in Subsection 4.2.2, Agronomic Practices, the agronomic and phenotypic characteristics of 

Maize Line HCEM485 have been evaluated in field trials (Stine, 2011) and determined by 

APHIS to be similar to its comparator corn cultivars, and its antecedent GA21 (USDA-APHIS, 

2011b). Maize Line HCEM485 would, therefore, be cultivated similar to other glyphosateresistant corn, and have impacts to plants communities similar to those described under the No 

Action Alternative.

An extension of a determination of nonregulated status to Maize Line HCEM485 would not be 

expected to increase or decrease the development of glyphosate-resistant weeds. As another 

glyphosate-resistant corn cultivar option, Maize Line HCEM485 would likely replace other 

glyphosate-resistant corn cultivars without changing the application of glyphosate to corn. No 

changes to glyphosate’s registered uses or labels for use on Maize Line HCEM485 are proposed 

by Stine, and no increase in glyphosate-resistant corn production acres is anticipated.

As discussed above, corn has few sexually compatible relatives in the U.S., and there is little risk 

of its cultivation contributing to weediness that may impact plants communities; further, APHIS 

has determined that there are no phenotypic differences between Maize Line HCEM485 and 

control lines that would contribute to enhanced weediness (USDA-APHIS, 2011b). Herbicide-
77

resistant corn such as Maize Line HCEM485 has the potential to impact other crops in the same 

fields or adjacent fields in later seasons as volunteers. As Maize Line HCEM485 is similar to 

other nonregulated corn cultivars, its volunteers would be controlled by common agronomic 

practices as discussed under the No Action Alternative. 

Based on these findings, the potential impact to other vegetation in corn and the landscapes 

surrounding cornfields from extending a determination of nonregulated status to Maize Line 

HCEM485 is not expected to differ from the No Action Alternative.

4.4.3 Gene Flow and Weediness

No Action Alternative: Gene Flow and Weediness

As described in Subsection 2.1.2, Agronomic Practices, corn is the largest crop grown in the U.S. 

in terms of value (USGC, 2010), acreage planted, and geographic area of production, and is 

predicted to remain an important crop in USDA projections to 2020 (USDA-OCE, 2011). Gene 

flow may occur through dispersal of vegetative tissues, pollen, or seed. Asexual reproduction 

and gene flow as a result of dispersal of vegetative tissues does not occur with corn. Corn is selfcompatible and primarily pollinated by wind or gravity, with minimal contribution from insect 

pollination (McGregor, 1976; Thomison, 2009), and is propagated by seed. 

As discussed in Subsection 2.3.3, Gene Flow and Weediness, although some teosinte species are 

culturally and biologically similar to corn, no successful weedy species have been documented 

(US-EPA, 2011b). There are no extant populations of sexually compatible species related to 

domesticated Z. mays within the continental U.S., its territories, or possessions; therefore, APHIS

(2011b) has concluded that there is not a significant risk of gene movement between corn and its 

wild or weedy maize relatives. 

The reproductive morphology of corn encourages cross-pollination between corn plants and 

there is no evidence (genetic or biological barriers) to indicate that gene flow is restricted 

between genetically modified, conventional, and organic corn. Spatial and temporal isolation 

can be the most effective barriers to gene exchange between corn crop cultivars. Requirements 

and methods to ensure seed and crop purity are discussed in more detail in Subsections 2.1.3, 

Corn Seed Production, and 2.1.4, Organic Corn Production.

Corn does not possess the characteristics for efficient seed-mediated gene flow. Through 

thousands of years of selective breeding by humans, corn has been extensively modified to 

depend on human cultivation for survival (Doebley, 2004). As a result of its domestication, corn 

is not able to survive in the wild and also has several traits that greatly reduce its ability to 

disperse via seeds (OECD, 2003). Corn seed lost after harvest may survive in fields and develop 

into volunteer plants, but such volunteers are controlled with common agronomic practices (see 

Subsection 2.3.2, Plants Communities). 

Horizontal gene flow or gene flow to unrelated species in any currently cultivated corn is 

unlikely, and its potential occurrence in any crop is discussed more theoretically than practically. 

It has never been documented under realistic conditions (Stewart, 2008) (see Subsection 2.3.3, 

Gene Flow and Weediness). The horizontal transfer of entire transgenes, including portions of 
78

the DNA that code for the production of specific proteins, has never been shown to occur in 

nature (Stewart, 2008), and the risk of its occurrence in corn cultivation is considered low. 

Preferred Alternative: Gene Flow and Weediness

Under the Preferred Alternative, Maize Line HCEM485 would be commercially available as an 

additional glyphosate-resistant corn option for use by producers. APHIS evaluated the potential 

for gene flow between Maize Line HCEM485 and its wild relatives, other corn cultivars, and 

other unrelated species. Phenotypic testing of Maize Line HCEM485 and agronomic trials have 

demonstrated the cultivar is similar to other glyphosate-resistant corn varieties and its antecedent 

GA21 corn (USDA-APHIS, 2011b). Therefore, its potential for gene flow and weediness would 

be no different than other corn varieties currently on the market as described under the No 

Action Alternative.

4.4.4 Microorganisms

No Action Alternative: Microorganisms

Soil microorganisms are important in soil structure formation, decomposition of organic matter, 

toxin removal, nutrient cycling, and most biochemical soil processes (Garbeva et al., 2004). 

They may also suppress soil-borne plant diseases and promote plant growth (Doran et al., 1996). 

As described in Subsection 2.3.4, Microorganisms, the main factors affecting microbial 

population size and diversity include soil and plant type, and agricultural management practices 

(crop rotation, tillage, herbicide and fertilizer application, and irrigation) (Garbeva et al., 2004). 

Plant roots, including those of corn, release a variety of compounds into the soil creating a 

unique environment for microorganisms in the rhizosphere. 

GE plants potentially impact soil microbes directly from the transfer of introduced genetic

material, exposure to expressed proteins through root exudation and crop residue incorporated 

into soil, or changes in agronomic practices used to produce crops. Indirect impacts may arise 

from changes in the amount and composition of residue from crops. 

Gene transfer between microorganisms is common (Keese, 2008; McDaniel et al., 2010). Yet, 

biodegradation of plant materials tilled into soils generally results in fragmentation of DNA strands 

into small pieces (Lerat et al., 2007; Levy-Booth et al., 2008; Hart et al., 2009), which would be 

unlikely to represent an intact entire cp4 epsps gene. Cleaves et al. (2011) have evaluated the ability 

of shorter DNA strands to adsorb to soil aggregates, potentially affecting their persistence in soil; 

however, these were likely unable to convey functional genes. However unlikely, if a 

microorganism incorporated an intact cp4 epsps gene, it might transfer the gene to other 

microorganisms, resulting in a greater presence of the gene in the environment. As described in 

Subsection 2.3.3, Gene Flow and Weediness, gene transfers between plants and microorganisms 

are thought to occur on an evolutionary timescale. The cp4 epsps gene in the form of herbicideresistant crops has been approved for release under 7 CFR part 340 and the plant pest provisions 

of the Plant Protection Act since 1994 (USDA-APHIS, 2012). An incremental increase in gene 

transfer among microorganisms under the No Action Alternative is unlikely.

The potential for intact CP4 EPSPS protein conveying glyphosate resistance to remain functional

in soils is remote, because the protein degrades once it is released from cells, decaying in soils 

(Australian Government, 2006). If some molecules did persist in soils, there is no reason to 
79

anticipate toxicity of the CP4 EPSPS protein to soil microbes. Studies of the impact of GE crops 

on soil microbial communities have indicated there have been minor to no non-target effects, but 

induced targeted alterations to the composition of the microbial community have usually resulted 

in the inhibition of plant pathogenic organisms (Kowalchuk et al., 2003). 

Root exudates have been found to promote certain microbial populations, such as soybeans 

symbiotic relationship with nitrogen-fixing bacteria, and other free-living microbes that have coevolved with plants that supply nutrients to and obtain food from their plant hosts (USDANRCS, 2004; Bais et al., 2006). Management practices used in corn production can affect soil 

microorganisms by altering microbial populations and activity through modification of the soil 

environment. As presented in Subsection 2.3.4, Microorganisms, crop rotation, irrigation, 

tillage, and agricultural chemicals such as fertilizers and pesticides affect microbial community 

structure and functions such as nutrient cycling, disease promotion or suppression, and presence 

in soil. As discussed in Subsection 2.1.2, Agronomic Practices, the adoption of glyphosateresistant corn (and other herbicide-resistant crops) has enabled the use of conservation tillage, 

creating less soil disturbance and retaining more crop residue which has been found to increase 

soil microbe population diversity (Locke et al., 2008). An agronomic practice may be beneficial 

for one microorganism but detrimental to another. For example, the primary agents degrading 

glyphosate in soil and water are microorganisms feeding on the herbicide (Senseman, 2007). As 

discussed in Subsection 2.3.4, Microorganisms, results from investigations into the toxicity of 

glyphosate to microorganisms are varied. Reviews of studies investigating the impact of 

glyphosate on soil microorganisms found that numerous studies did not detect adverse effects 

under field use conditions, others found minor effects that could not be separated from changes 

in habitat, and still others reported effects at or near normal glyphosate use rates, but in most 

cases, the effects were minor and temporary (Giesy et al., 2000). Other studies have implicated 

glyphosate in an increase in the population and virulence of certain plant diseases, as well as the 

increased susceptibility to some diseases in glyphosate-resistant crop varieties (as reviewed in 

Johal and Huber, 2009). The authors suggest measures to minimize this potential include using 

the minimum amount of glyphosate necessary for weed management, amending soils with 

micronutrients, detoxifying meristematic (i.e., growth) tissues by adding chelating agents to the 

soil, and detoxifying root exudates through the regular inoculation of nitrogen-fixing organisms

(Johal and Huber, 2009). 

APHIS has previously examined in detail the potential impacts of glyphosate to microorganisms 

in the cultivation of glyphosate-resistant alfalfa and sugar beets (USDA-APHIS, 2010; USDAAPHIS, 2011a). Based on extensive review of the literature, they conclude glyphosate 

application might favor development of detrimental microbial species (or harm some beneficial 

microbes); however, to date, there is no conclusive evidence linking applications of glyphosate 

to changes in soil microbial communities that have adverse effects on plants grown in those soils.

Corn cultivation, including the production of glyphosate-resistant corn and its potential impacts 

to soil microorganisms, is expected to continue under the No Action Alternative. The majority 

of corn grown in the U.S. is herbicide resistant, and glyphosate is the most applied herbicide to 

corn (USDA-ERS, 2011a; USDA-NASS, 2011c). Farmers have access to non-glyphosateresistant corn varieties, and manage their crops by implementing practices to control pests and 

weeds, including the use of glyphosate.
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Preferred Alternative: Microorganisms

Extension of a determination of nonregulated status to Maize Line HCEM485 is not expected to 

result in any new impacts to microbial communities. Maize Line HCEM485 is genetically 

equivalent to its GA21 antecedent for expression of the EPSPS protein (Stine, 2011; USDAAPHIS, 2011b). All the sequences inserted into Maize Lane HCEM485 are the same as those 

associated with the native EPSPS-encoding gene in corn (USDA-APHIS, 2011b). As such, 

nothing new or unique would be introduced into the environment that may impact the microbial 

community under the Preferred Alternative.

Maize Line HCEM485 has been determined to be agronomically and compositionally similar to

its antecedent GA21, as well as other nonregulated glyphosate-resistant corn varieties (USDAAPHIS, 2011b). It is not expected to change the acreage or area of glyphosate-resistant corn 

production that potentially would expand the use of glyphosate herbicide with potential impacts 

to soil microorganisms. Maize Line HCEM485 is another glyphosate-resistant corn cultivar 

likely to replace other nonregulated glyphosate-resistant corn varieties. Approximately 72% of 

corn cultivated in the U.S. today is herbicide-resistant and the majority of herbicide-resistant 

corn is glyphosate-resistant (Duke and Powles, 2009; USDA-ERS, 2011a). Because Maize Line 

HCEM485 is agronomically similar to its antecedent GA21 and other glyphosate-resistant and 

conventional corn, its cultivation would not change the agronomic practices needed for its 

cultivation, such as amount and rate of glyphosate application. Since the use of glyphosate for 

corn production is not expected to change under the Preferred Alternative, there would be no 

change to potential impacts to microorganisms from those of the No Action Alternative.

4.4.5 Biodiversity

No Action Alternative: Biodiversity 

All the plants, animals, and microorganisms interacting in an ecosystem contribute to 

biodiversity (Wilson, 1988) that provides valuable life functions. In agriculture, biodiversity 

contributes to critical functions such as pollination, genetic introgression, biological control, 

nutrient recycling, and other processes the loss of which requires costly management (Altieri, 

1999). Concerns regarding the potential impacts to biodiversity associated with the introduction 

of GE crops (and crops in general) include the loss of diversity, which can occur at the crop, 

farm, and/or landscape scale (Visser, 1998; Ammann, 2005; Carpenter, 2011) (see Subsection 

2.3.5, Biodiversity). 

At the crop scale, research suggests that developing GE crops has introduced novel genes that

has not decreased crop diversity because of widespread use of the traits in multiple breeding 

programs, and the technology enables the introduction of novel genes in crops (Ammann, 2005; 

Carpenter, 2011). Additionally, the concern for the loss of genetic variability has led to the 

establishment of an extensive network of genebanks (van de Wouw et al., 2010), including an 

active collection of more than 14,000 accessions of corn at the ARS North Central Regional 

Plant Introduction Station at Iowa State University, Ames, Iowa (USDA-ARS, 2005). These 

collections are shared with researchers worldwide, which helps ensure a continuous reservoir of 

genetic diversity for future crop development. Under this alternative, growers have access to 

existing nonregulated herbicide-resistant and other GE corn varieties, as well as other non-GE 

corn varieties, while Maize Line HCEM485 would remain a regulated article.
81

At the farm scale, agronomic practices that can impact biodiversity include cropping practices 

(e.g., strip or contour cropping, crop rotation), soil conservation practices that maintain grass 

strips, windbreaks and shelterbelts and the like, tillage, and the application of agrochemicals. 

The rotation of crops and strip contour cropping provide varied habitat that can benefit 

biodiversity. Recently, there has been an increase in corn-to-corn rotation given the profitability 

of corn production (USDA-ERS, 2011d). As discussed in Subsection 2.1.2., Agronomic 

Practices, continuous corn production must be highly managed to maintain productivity, which 

can be less beneficial to biodiversity; however, the practice does accumulate more crop residue 

that benefits some species. The establishment of soil conserving grass and other vegetative 

borders stabilize soil that maintains additional wildlife habitat, and improves the quality of 

existing habitat (such as surface water quality) that contributes to biodiversity. Allowing 

unproductive field edges to become managed wildlife habitat promotes diversity in both plants 

and animal species (Sharpe, 2010). 

Herbicides are used to control plants in areas where humans do not want them. As described in 

Subsection 2.1.2, Agronomic Practices, weeds compete with crops for light and nutrients, 

reducing yields. Glyphosate effectively kills grass and broadleaf plants when applied at the 

recommended rates. At the farm scale, herbicide use in agricultural fields may impact 

biodiversity by decreasing weed quantities or causing a shift in weed species present in the field, 

which may affect those insects, birds, and mammals that utilize these weeds. The quantity and 

type of herbicide use associated with herbicide-resistant corn crops, however, is dependent on 

many variables, including cropping systems, type and abundance of weeds, production practices, 

and individual grower decisions. See Subsection 2.1.2, Agronomic Practices, for a detailed 

discussion of pesticide use in corn production. The effects of glyphosate on plants and animals 

are presented in the following discussion of landscape-scale biodiversity. 

Use of herbicide-resistant crops such as corn has been linked to increased rates of conservation 

tillage in U.S. crop production (Givens et al., 2009). This promotes biodiversity by allowing the 

establishment of other plants between crop rows and the accumulation of more plant residue that 

creates more soil organic matter, food, and cover for wildlife. In a review of literature that 

assessed the impacts of GE crops on biodiversity, Carpenter (2011) found that, for the most part, 

impacts to biodiversity have been positive due to increased yields, decreased usage of 

insecticides, use of more environmentally friendly herbicides, and facilitation of conservation 

tillage. In 2010, 62% of planted corn acreage in 19 surveyed states was dedicated to no-till or 

minimum till systems (USDA-NASS, 2011c). As described in Subsection 2.3.2, Plants 

Communities, the increasing incidence of herbicide-resistant weeds is also causing farmers to 

turn to more diversified weed management strategies, including increased tillage that potentially 

reduces biodiversity. 

Crop production in general impacts biodiversity at the landscape scale by potentially converting 

natural lands that have greater animal and plant species diversity to more monocultural 

landscapes. Corn is the largest crop grown in the U.S. in terms of acreage planted and 

geographic area of production with over 92 million planted acres in 2011 (USDA-NASS, 

2011b). USDA projections to 2020 indicate the acreage devoted to corn production in the U.S. 

will remain relatively stable at this level (USDA-OCE, 2011). 
82

Area-wide herbicide application may negatively impact species that are dependent on the 

targeted weeds, reducing diversity. As stated above, the majority of corn cultivated in the U.S. is 

treated with herbicides and glyphosate is the most-applied herbicide to corn (USDA-NASS, 

2011c). Potential impacts to landscape-scale diversity can be related to the effects of herbicides 

on non-target animal and plant species. Assessments of the toxicity of glyphosate to animal 

species indicate a minimal risk to animals, but it is toxic to targeted plants and may affect nontargeted plants and animals through spray drift, volatilization (i.e., evaporation) and runoff. 

Inadvertent exposure may cause adverse effects to plants composing animals’ habitat that could 

lead to a decrease in biodiversity. As discussed in Subsection 2.3.1, Animal Communities, 

glyphosate was found by the EPA to be no more than slightly toxic to birds, moderately toxic to 

practically nontoxic to fish, and practically nontoxic to aquatic invertebrates and honeybees (USEPA, 1993b). The EPA is currently evaluating additional labeling requirements concerning

BMPs for controlling pesticide spray drift (see Subsection 2.3.2, Plants Communities). While 

herbicide use potentially affects biodiversity, the application of pesticides in accordance with 

registered uses and label instructions, and careful management of chemical spray drift, 

minimizes the potential impacts from their use. 

In 2009, the EPA initiated reregistration of glyphosate and has identified additional data needs. 

Part of the risk assessment will include an acute avian oral toxicity study for passerine species. 

Additionally, some inert ingredients used as surfactants are more toxic than glyphosate to aquatic 

organisms, and will be evaluated for acute toxicity to estuarine and marine mollusk, 

invertebrates, and fish (US-EPA, 2009b). 

Preferred Alternative: Biodiversity

Under the Preferred Alternative, an extension of a determination of nonregulated status to Maize 

Line HCEM485 would provide growers an additional glyphosate-resistant corn variety. Maize 

Line HCEM485 is functionally the same as its antecedent GA21 and other GE and non-GE corn 

with regard to agronomic characteristics, growth, reproductive habit, utilization of resources, and 

production practices (Stine, 2011; USDA-APHIS, 2011b). Extending a determination of 

nonregulated status to Maize Line HCEM485 is unlikely to have any direct effects on non-target 

organisms associated with exposure to its gene products and the modified EPSPS protein 

expressed by the cultivar. The genetic material in and proteins produced by Maize Line 

HCEM485 are similar to those of the nonregulated antecedent GA21 and other corn varieties in 

commercial production (USDA-APHIS, 2011b). An extension of a determination of 

nonregulated status to Maize Line HCEM485 would, therefore, have no impact on biodiversity at 

the crop-, farm- or landscape scales.

Because Maize Line HCEM485 is another glyphosate-resistant cultivar option, it would likely

replace other glyphosate-resistant corn varieties without expanding the acreage or area of corn 

production that could impact farm- and landscape-scale biodiversity. Approximately 72% of 

corn planted in the U.S. in 2011 was herbicide resistant, and the majority of herbicide-resistant 

corn is glyphosate-resistant (Duke and Powles, 2009; USDA-ERS, 2011a). Also, based on its 

similarity to other corn as described above, Maize Line HCEM485 would not result in changes to 

agronomic practices such as crop rotation, soil conservation, tillage, weed management, or 

pesticide use that potentially impact farm- or landscape-scale biodiversity. 
83

Based on the above information, APHIS has concluded the extension of a determination of 

nonregulated status to Maize Line HCEM485 under the Preferred Alternative would not have 

impacts to crop-, farm-, or landscape-scale biodiversity any different than other currently 

available glyphosate-resistant corn cultivars. As such, the impacts to biodiversity under this 

alternative would be similar to the No Action Alternative.

4.5 Human Health 

4.5.1 No Action Alternative: Human Health

As discussed in Subsection 2.1.1, Acreage and Area of Corn Production, 88% of corn grown in 

the U.S. in 2011 was GE (USDA-ERS, 2011a). The majority of GE herbicide-resistant corn 

grown in the U.S. is glyphosate resistant (Duke and Powles, 2009). Human health concerns 

associated with GE crops include the potential toxicity of the introduced genes and their 

products, the expression of new antigenic proteins, and/or altered levels of existing allergens 

(Malarkey, 2003; Dona and Arvanitoyannis, 2009). Previous studies of the EPSPS protein, 

which confers glyphosate resistance, found that the EPSPS protein expressed through genetic 

engineering poses no potential for toxicity or allergenicity (Harrison et al., 1996; Ridley et al., 

2002; Batista et al., 2005; Hoff et al., 2007; Herouet-Guicheney et al., 2009). Some people are 

allergic to corn, but corn is not included in the FALCPA as one of the most common food 

allergens (see Subsection 2.4, Human Health). An additional concern with GE food crops is the 

potential for increased levels of anti-nutrients (Dona and Arvanitoyannis, 2009). As discussed in 

Subsection 2.4, Human Health, there are several naturally occurring anti-nutrients found in corn, 

including phytic acid, DIMBOA, raffinose, and low levels of trypsin and chymotrypsin inhibitors

(OECD, 2002). In a study of the CP4 EPSPS protein conferring glyphosate resistance, Ridley et 

al. (2002) found the genetic modification to confer glyphosate resistance did not significantly 

change any of the 51 biologically and nutritionally important components evaluated. 

Under the FFDCA, it is the responsibility of food and feed manufacturers to ensure that the 

products they market are safe and properly labeled. The food safety evaluation of the EPSPS 

protein imparting glyphosate resistance was completed by the FDA on the GA21 corn variety 

(BNF No. 000051) on February 10, 1998 (US-FDA, 1998a). According to the consultation note, 

“Monsanto has concluded that corn containing transformation event 

GA21 is not materially different in composition, nutrition, and 

safety from corn currently grown, processed, marketed, and 

consumed for animal feed or human food. At this time, based on 

Monsanto's description of its data and analyses, the Agency 

considers Monsanto's consultation on corn from varieties containing 

transformation event GA21 to be complete.”

No food safety issues were found by the FDA in previous consultations regarding the EPSPS 

protein in corn or any other GE corn cultivars (See the FDA website Final Biotechnology 

Consultations http://www.fda.gov/Food /Biotechnology/Submissions/ucm225108.htm). 

Agricultural production of nonregulated GE and non-GE corn utilize EPA-registered pesticides 

for insect and plant pest management under the No Action Alternative, including glyphosate. 

Glyphosate may also be applied to regulated Maize Line HCEM485 cultivated under confined 
84

conditions. The environmental risks of pesticide use are assessed by the EPA in the pesticide 

registration process and a pesticide is regularly reevaluated by the EPA to maintain its registered 

status under FIFRA. The human health effects from exposure to glyphosate have been evaluated 

by the EPA. The 1993 glyphosate RED presents the data used by the EPA for chemical 

reregistration (see US-EPA, 1993b). As previously discussed in Subsection 2.4, Human Health, 

the review for reregistration began in July 2009; the EPA is currently conducting a 

comprehensive human health assessment for all uses of glyphosate and its salts (US-EPA, 

2009b). The glyphosate RED presents the EPA’s analysis of the toxicity, carcinogenicity, and 

developmental toxicity of this herbicide. Glyphosate is classified as having low toxicity via the 

oral, dermal, and inhalation routes and is not classified as a carcinogen or teratogen (US-EPA, 

2009b; US-EPA, 2009c). Moreover, neurotoxicity has not been reported in any acute, 

subchronic, chronic, developmental, or reproductive studies, although additional studies will 

occur as part of the current review process (US-EPA, 2009c). Based on additional toxicity tests, 

the EPA determined the main glyphosate metabolite AMPA does not require regulation (USEPA, 2009c).

As presented in Subsection 2.4, Human Health, pesticide tolerance levels for glyphosate on field 

corn such as Maize Line HCEM485 have been established (US-EPA, 2011e). Tolerances are the 

limits on the amount of pesticide that may remain on or in foods marketed in the U.S., that are 

established for every pesticide based on its potential risks to human health. The maximum 

tolerance level for glyphosate in field corn is 5.0 ppm for grain (40 CFR §180.364). 

It has been suggested that the importance producers place on worker safety, perceived increased 

simplicity and flexibility of farm management, and decreased risk in production can be partially 

attributed to the high rate of adoption of GE crops (NRC, 2004). Producers and farm workers 

experience reduced exposure to potentially harmful pesticides compared to before adoption of 

GE crops and are also able to spend less time applying pesticides with greater flexibility in 

determining when pesticides are applied. There are no data indicating that workers exposed to 

herbicide-resistant corn (raw or byproducts), such as that could occur during production, 

transportation, and milling, have experienced adverse reactions. While a small portion of the 

population does suffer from corn allergies, the EPSPS protein that confers glyphosate resistance 

in Maize Line HCEM485 has been determined not to be an allergen (see Subsection 2.4, Human 

Health). 

Agricultural workers that routinely handle glyphosate (mixers, loaders, and applicators) may be 

exposed during and after use. Due to glyphosate’s low acute toxicity and lack of carcinogenicity 

and other toxicological concerns, occupational exposure data is not required for reregistration 

(US-EPA, 1993b); however, the glyphosate RED does classify some end-use glyphosate 

products as eye and skin irritants and recommends PPE be worn by mixers, loaders, and 

applicators (US-EPA, 1993b). Additionally, due to the potential for skin and eye irritation, the 

EPA has set the restricted entry interval for glyphosate to 12 hours after products have been 

applied. Due to the expected short-term dermal and inhalation exposures of occupational 

handlers and growers, no endpoints were identified by the HED, and as such, no occupational 

handler or occupational post-application assessments are required for reregistration (US-EPA, 

2009c). Current EPA-approved labels for glyphosate include precautions and measures to 

protect human health. When used consistent with the label, pesticides present minimal risk to 

human health and safety. 
85

4.5.2 Preferred Alternative: Human Health

Maize Line HCEM485 is a GE variety of corn that has been modified to add resistance to the 

herbicide glyphosate (Stine, 2011). This resistance was conferred using an altered sequence of 

DNA derived from the corn genome accomplished by the removal and modification of the epsps

gene from an inbred corn line so that it encodes a double mutated 2mEPSPS enzyme, which was 

subsequently reintroduced back into the corn DNA. The 2mEPSPS enzyme product is identical 

to that produced by the antecedent GA21 corn (USDA-APHIS, 2011b). In addition, all 

promoter, intron, and terminator sequences inserted into HCEM485 are the same as those already 

associated with the native EPSPS-encoding gene in corn. As discussed above, studies have 

found that the EPSPS protein expressed in glyphosate-resistant crops is compositionally similar 

to, and is as safe and nutritional as, the same non-GE crops (Ridley et al., 2002; Batista et al., 

2005; Herouet-Guicheney et al., 2009). APHIS considers the FDA regulatory assessment in 

making its determination of the potential impacts of removing a new agricultural product from 

regulated status. As discussed in Subsection 2.4, Human Health, a biotechnology consultation of 

the EPSPS protein that confers glyphosate resistance was completed by the FDA on the GA21 

corn variety (BNF No. 000051) on February 10, 1998 (US-FDA, 1998a). According to the 

consultation note, 

“Monsanto has concluded that corn containing transformation event 

GA21 is not materially different in composition, nutrition, and 

safety from corn currently grown, processed, marketed, and 

consumed for animal feed or human food. At this time, based on 

Monsanto's description of its data and analyses, the Agency 

considers Monsanto's consultation on corn from varieties containing 

transformation event GA21 to be complete.”

Stine submitted a safety and nutritional assessment of food and feed derived from Maize Line 

HCEM485 to the FDA in December 2010 in support of the consultation process with the FDA 

for the commercial distribution of Maize Line HCEM485. Based on the above information and 

its similarity to the antecedent GA21 corn, potential impacts to food safety from production of 

Maize Line HCEM485 would be similar to the No Action Alternative. 

Under the Preferred Alternative, pesticide tolerance levels for glyphosate on field corn would not 

change. Tolerances are the limits on the amount of pesticide that may remain on or in foods 

marketed in the U.S. established for every pesticide based on its potential risks to human health. 

As specified in 40 CFR §180.364, the glyphosate tolerance level for field corn grain is 5.0 ppm. 

As discussed in Subsection 4.2.2, Agronomic Practices, the use of glyphosate in corn production 

would be unaffected by an extension of a determination of nonregulated status to Maize Line 

HCEM485. The application rate of glyphosate in corn would not likely change as a result of the 

Preferred Alternative since Maize Line HCEM485 is expected to replace other glyphosateresistant corn cultivars (see Subsection 4.2.1, Acreage and Area of Corn Production), is similar 

to other nonregulated glyphosate-resistant cultivars in its cultural requirements, and no change to 

the registered use of glyphosate is proposed. 

Potential risks to occupational handlers and growers during glyphosate application to Maize Line 

HCEM485 would be the same as those presented under the No Action Alternative. There would 

be no increased risk to workers’ health or safety from exposure to Maize Line HCEM485 corn or 
86

byproducts during typical agricultural-related activities. Moreover, as discussed above, the 

application rate of glyphosate would not likely change and no change to the registered use of 

glyphosate is proposed under the Preferred Alternative. Potential risks to farm workers from the 

use of glyphosate would be the same as the No Action Alternative.

APHIS concludes impacts to human health or worker safety from an extension of nonregulated 

status to Maize Line HCEM485 under the Preferred Alternative would be similar to the No 

Action Alternative

4.6 Animal Feed

4.6.1 No Action Alternative: Animal Feed

As described in Subsection 2.5, Animal Feed, most of the corn produced in the U.S. is for animal 

feed that is consumed primarily by cattle, poultry, and swine (NCGA, 2011; USDA-ERS, 

2011d). Corn comprises approximately 96% of the total feed grain produced in the U.S. (USDAERS, 2011d). In 2011, corn was grown on 92.3 million acres (USDA-NASS, 2011b) and

measurably produced in all states but Alaska (USDA-NASS, 2009a). As discussed in Subsection 

2.5, Animal Feed, 44% of the corn consumed in the U.S. in 2010 was used for animal feed 

(USDA-ERS, 2011d). In 2011, 72% of the corn produced in the U.S. was genetically engineered 

to be resistant to herbicides, consisting primarily of glyphosate-resistant cultivars (Duke and 

Powles, 2009; USDA-ERS, 2011a). The amount of corn that is used for feed is dependent on a 

number of factors such as the number of animals that are fed corn, its supply and price, the 

amount of supplemental ingredients added, and the supply and price of competing ingredients 

(USDA-ERS, 2011d). Corn forage, silage, grain, and refined corn feed products from currently 

cultivated GE herbicide-resistant and conventional corn varieties are utilized by livestock 

producers. 

It is the responsibility of feed manufacturers to ensure that the products they market are safe and 

properly labeled and feed derived from GE corn must comply with all applicable legal and 

regulatory requirements, which in turn protect human health (see Subsection 2.5, Animal Feed). 

All applicants who wish to commercialize a GE variety that will be included in the food 

supply complete a consultation with the FDA to identify and discuss relevant safety, 

nutritional, or other regulatory issues regarding the bioengineered food and submits a 

summary of its scientific and regulatory assessment of the food to FDA (US-FDA, 2012b). 

The FDA evaluates the submission and responds to the developer by letter. Stine submitted

their final food consultation regarding Maize Line HCEM485 in December 2010 which is 

pending review by the FDA. It will be posted on the FDA website Final Biotechnology 

Consultations http://www.fda.gov/Food/ Biotechnology/Submissions/ucm225108.htm when 

completed. In addition, a biotechnology consultation of the EPSPS protein was completed by the 

FDA on the antecedent GA21 corn variety (BNF No. 000051) on February 10, 1998 (US-FDA, 

1998a). No food safety issues were found by the FDA in their review of Monsanto’s safety and 

nutritional assessment of GA21 corn and the modified EPSPS protein (see the FDA website 

Final Biotechnology Consultations http://www.fda.gov/Food/Biotechnology/Submissions 

/ucm225108.htm). 

Agricultural production of existing commercially available glyphosate-resistant corn varieties 

uses EPA-registered pesticides, including glyphosate. The interval between when corn is treated 
87

with glyphosate and the grain may be subsequently harvested is seven days (Bradley et al., 

2010). The interval between post-harvest application of glyphosate after corn grain has been 

harvested and when the corn vegetation may be harvested or used as feed varies with product 

labels, for example the Roundup Power Max® interval is seven days while the Glyphosate 41 

Plus ® interval is eight weeks (CropSmart, 2009; Monsanto, 2010). Tolerances are the limits on 

the amount of pesticide that may remain on or in foods marketed in the U.S. that are established 

for every pesticide based on its potential risks to human health. The maximum tolerance level 

for glyphosate in field corn is 5.0 ppm for grain and is 6.0 ppm for forage (40 CFR §180.364). 

4.6.2 Preferred Alternative: Animal Feed

As described in Subsection 4.2.1, Acreage and Area of Corn Production, no change to the area or 

acreage of corn production is expected to occur as the result of extending a determination of 

nonregulated status to Maize Line HCEM485. Also, as described in Subsection 4.2.2, 

Agronomic Practices, the cultural requirements and agronomic practices for corn production that

could impact the supply of corn-based animal feed would not change under this alternative 

because agronomic and growth characteristics of Maize Line HCEM485 are similar to other 

commercially available glyphosate-resistant corn. As described for the No Action Alternative, 

the amount of corn that is used for feed is dependent on several factors, including price, supply, 

and the number of animals that are fed corn (USDA-ERS, 2011d). Because herbicide-resistant 

corn is the majority of corn produced in the U.S. today, and most of that is glyphosate resistant 

(USDA-ERS, 2011a), Maize Line HCEM485 would likely replace other glyphosate-resistant 

cultivars without impacting the supply of corn for animal feed.

Stine has submitted compositional and nutritional characteristics of Maize Line HCEM485 grain 

and forage to APHIS (Stine, 2011). Samples of Maize Line HCEM485 and its comparators that 

were sprayed with glyphosate were collected from six different field trial locations (four for 

grain samples and two for forage samples) and analyzed for comparable nutritional components 

in accordance with Organisation for Economic Co-operation and Development (OECD)

guidelines (OECD, 2002). Tested parameters include proximates (protein, fat, carbohydrates, 

fiber, ash, and moisture), minerals, amino acids, fatty acids, vitamins, isoflavones, and 

antinutrients (i.e., ferulic acid, phytic acid, trypsin inhibitor, raffinose, furfural, inositol, and ρcoumaric acid) (Stine, 2011). Maize Line HCEM485 is similar in compositional and nutritional 

characteristics to other varieties of GE and non-GE corn (Stine, 2011; USDA-APHIS, 2011b).

A biotechnology consultation of the EPSPS protein that confers glyphosate resistance in the 

GA21 corn variety has previously been completed. (See Subsection 4.5, Human Health). Stine 

submitted a safety and nutritional assessment of food and feed derived from Maize Line 

HCEM485 to the FDA in December 2010 in support of the consultation process with the FDA 

for the commercial distribution of Maize Line HCEM485 (Stine, 2011). Based on the above 

information and its similiarity to the antecedent GA21 corn, potential impacts on the safety of 

Maize Line HCEM485 is expected to be similar to the No Action Alternative.

As discussed above, label restrictions for glyphosate’s application to corn prohibits harvesting 

the grain prior to seven days after application and the interval for harvesting or feeding the 

vegetation is dependent on the individual glyphosate product label. As discussed in Subsection 

4.2.2, Agronomic Practices, the registered uses of glyphosate on Maize Line HCEM485 or other 

corn would not change as a result of the Preferred Alternative, nor would herbicide label 
88

restrictions for feeding corn after treatment. Similarly, no change to the EPA-established 

tolerances of glyphosate in treated corn intended for forage or grain harvested for animal feed 

that could impact animal health would be required for the use of glyphosate on Maize Line 

HCEM485 . 

Based on a review of field and laboratory data and scientific literature provided by Stine (2011), 

as well as safety data available on other glyphosate-resistant corn in commercial production,

APHIS has concluded that a determination of nonregulated status to Maize Line HCEM485

would not adversely impact the safety of animal feed and animal health. Overall impacts of the 

Preferred Alternative would be similar to the No Action Alternative.

4.7 Socioeconomic Impacts

4.7.1 Domestic Economic Environment

No Action Alternative: Domestic Economic Environment

Under the No Action Alternative, Maize Line HCEM485 corn would continue to be a regulated 

article under 7 CFR part 340, cultivated only in limited test fields. Farmers and other parties 

who are involved in production, handling, processing, or consumption of corn would not have 

access to Maize Line HCEM485 corn, but would have access to existing nonregulated herbicideresistant, conventional, GE, and organic corn varieties. In terms of value, corn is the primary 

U.S. crop exceeding $66.7 billion in 2010 (USDA-NASS, 2011f), and it is expected corn would 

retain current planted acreage levels at least until 2020 (USDA-OCE, 2011). Almost all of the 

U.S. corn supply (99.8% in 2010/11) comes from new annual domestic production (USDA-ERS, 

2011g). In the 2010/11 marketing year, less than half (42.8%) of domestic corn usage was for 

feed, while approximately 44.7% of domestic use was for the production of ethanol (USDAERS, 2011g). Total operating costs for U.S. corn production were $275.58 per planted acre 

(USDA-ERS, 2011c). Corn is widely produced in the U.S. (see Subsection 2.1.1, Acreage and 

Area of Corn Production, Figure 1). The most productive regions are the Heartland and 

Northern Crescent, and the two most profitable are the Heartland and Northern Great Plains 

(USDA-ERS, 2011c). As discussed in Subsections 2.1.4, Organic Corn Production, and 2.6.1, 

Domestic Economic Environment, organic corn production is a small portion of the U.S. corn 

market. The value of corn produced for grain or seed from organic-certified farms in the U.S. in 

2008 was nearly $111.4 million (USDA-NASS, 2010a).

Most corn planted in the U.S. today are stacked GE varieties with both herbicide and insect 

resistance (USDA-ERS, 2011a). The widespread adoption of herbicide-resistant corn has been 

attributed to the cost savings for production, among other non-monetary benefits as described in 

Subsection 2.1.2, Agronomic Practices (Duke and Powles, 2009; NRC, 2010; Green and Owen, 

2011). Of the herbicide-resistant corn varieties on the market today, growers may choose from 

glyphosate, glufosinate, glyphosate stacked with immidazolinone resistance traits (USDAAPHIS, 2012), and glufosinate (Monsanto, 2011b).

GE technology is patented and GE seeds are proprietary in the U.S. (NRC, 2010). The costs for 

GE seed are higher than that for conventional seed, as GE seed includes technology fees (NRC, 

2010). The higher seed costs, however, may be offset by other premiums offered by companies, 

such as discounts for herbicides to use on the resistant crop, and reductions in crop insurance 
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(NRC, 2010). As discussed in Subsection 2.6.1, Domestic Economic Environment, estimates of 

the economic benefits of herbicide-resistant crops to farmers are limited (NRC, 2010), and 

studies that have been conducted have had mixed results. Overall, these studies indicate in the 

early years of the adoption, GE cultivars exerted downward pressure on crop prices while the 

earnings of adopting farmers increased, and barriers to market access for GE crops reduced 

grower income (NRC, 2010). 

Farmers have recently broadened weed management to treat herbicide-resistant weeds which 

may be impacting yields, leading to more variety in herbicide application and increased tillage, 

potentially incurring higher production costs. Weirich et al. (2011), however, investigated the 

economic effects of alternative glyphosate weed resistance management programs, finding that 

although they increased cost substantially, higher yields offset these costs such that no 

statistically significant decrease in net returns occurred. Their study suggests growers may be 

able to effectively respond to glyphosate resistance using weed BMPs without substantially 

affecting their returns.

As indicated in Subsection 2.1.1, Acreage and Area of Corn Production, the trend over the last 

several years in the U.S. has been to stack herbicide resistance with primarily insect-resistant 

traits. Developers have recently sought approvals for corn varieties that have multiple herbicide 

and insect resistance, as well as other value added traits (USDA-APHIS, 2012). Herbicideresistant-only corn has consistently comprised approximately 22 to 23% of planted corn in the 

U.S. since 2007 (USDA-ERS, 2011a). Two companies hold the licenses for the majority of 

herbicide-resistant corn in the U.S.: Monsanto patented glyphosate-resistant corn technology 

and offers varieties in their Roundup Ready® corn lines, and Bayer CropScience licenses 

glufosinate-resistant corn in their LibertyLink® corn lines. Growers have perceived a lack of 

competition in the U.S. herbicide- and insect-resistant seed corn market based on substantial 

increases in the price of GE seed in the last several years (Neuman, 2010); although, 

concentration of the U.S. seed market has been ongoing since passage of the Plant Variety 

Protection Act in the 1970s established proprietary rights for certain plant varieties (FernandezCornejo, 2004). In 2010, corn seed comprised 30% of total per acre operating costs for farmers 

(USDA-ERS, 2011c). Industry has responded that the quality of seed offered has improved, and 

new GE traits have been added that lower costs associated with improved insect and weed 

control, among other production costs (Neuman, 2010). 

Preferred Alternative: Domestic Economic Environment

Under the Preferred Alternative, farmers and other parties who are involved in the production, 

handling, processing, or consumption of corn would have access to Maize Line HCEM485. 

Maize Line HCEM485 is similar in its composition, growth habits, and cultural requirements to 

the antecedent GA21, its comparators and other nonregulated glyphosate-resistant corn (Stine, 

2011; USDA-APHIS, 2011b). Since this new cultivar is glyphosate-resistant, Maize Line 

HCEM485 would directly compete with the market share of other glyphosate-resistant corn 

varieties. As discussed above, herbicide-resistant corn dominates U.S. corn production, either as 

herbicide-resistant-only varieties or stacked with other traits; therefore, Maize Line HCEM485 

would likely replace other glyphosate-resistant corn cultivars without impacting corn acreage or 

production area that may affect domestic markets. As another glyphosate-resistant corn cultivar 

in the market, nonregulated Maize Line HCEM485 may increase competition, the extent of 
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which is dependent upon growers finding value in it. As discussed above, growers may currently 

choose from glyphosate, glufosinate, and glyphosate stacked with immidazolinone resistance 

traits. It is reasonable to assume Maize Line HCEM485 may be stacked with other traits, similar 

to other glyphosate-resistant corn cultivars. APHIS assumes that the technology fees for Maize 

Line HCEM485 seed would be similar to those charged by developers for other GE crop 

varieties already in the marketplace. 

Since Maize Line HCEM485 is similar in growth habits and cultural requirements to other 

nonregulated herbicide-resistant, GE and non-GE corn varieties (Stine, 2011), no changes to 

agronomic inputs or practices would be anticipated that may impact on-farm costs for corn 

producers or the U.S. domestic corn market. As discussed above, farmers are broadening their 

weed control tactics in response to developing herbicide-resistant weeds, including glyphosateresistant weeds (see Subsection 2.3.2, Plants Communities, Table 2). These BMPs increase costs 

of production; however, the costs appear to be offset by increases in yields, having little negative 

impact to net returns (Weirich et al., 2011). As discussed above, Maize Line HCEM485 is 

similar to and expected to replace other glyphosate-resistant cultivars, and would, therefore, have 

similar impacts on the development of herbicide-resistant weeds and weed management practices 

as the No Action Alternative.

 As discussed under the No Action Alternative, the organic corn market serves a smaller 

consumer niche for corn in the U.S. corn market. Because of Maize Line HCEM485’s similarity 

to other currently available GE corn varities in its reproductive characteristics, it is expected that 

impacts on organic corn production would be similar to the No Action Alternative. U.S. organic 

producers would continue to to be able to meet organic certification requirements as outlined in 

Subsection 2.1.4, Organic Corn Production, by implementing standard practices to preserve the 

identity of their organic corn crop. 

Based upon the above, an extension of a determination of nonregulated status to Maize Line 

HCEM485 would have potential domestic economic impacts no different than those currently 

observed under the No Action Alternative . 

4.7.2 Trade Economic Environment

No Action Alternative: Trade Economic Environment

Under the No Action Alternative, Maize Line HCEM485 would continue to be a regulated 

article. Farmers, processors, and consumers in the U.S. would not have access to Maize Line 

HCEM485, but do have access to existing nonregulated herbicide-resistant and non-GE corn 

varieties, as do the major U.S. corn export competitors. 

The U.S. is the leading exporter of corn in the world market (see Subsection 2.6.2, Trade 

Economic Environment, Figure 9), while other important exporters are Argentina, Brazil, and 

Ukraine. In the 2010/2011 marketing year (August to September), the U.S. exported more than 

half of the world’s corn with Japan, Mexico, and South Korea the major importers (USDA-FAS, 

2011a). In 2010, corn exports were worth approximately $9.1 billion (USDA-ERS, 2010c). 

U.S. corn supply, the value of the U.S. dollar and other currencies, oil prices, U.S. and 

international agricultural policy, the U.S. and international biofuels sector, livestock and meat 

trade, prices, and population growth are all factors affecting where and how much of U.S. corn is 
91

exported (USDA-ERS, 2009; USDA-OCE, 2011). In addition, consumer perception of GE crop 

production and products derived from GE crops may present barriers to trade. Over the past 

decade, U.S. corn export share has eroded as exports have remained relatively stable while 

global exports have increased by almost 20% (See Subsection 2.6.2, Trade Economic 

Environment, Figure 9). U.S. share of world corn production has declined as well, even as total 

world production increased (Figure 10). This is attributed to greater domestic use of U.S. corn, 

smaller corn crops, and increased competition from other major corn exporters such as 

Argentina, Brazil, and Ukraine (USDA-FAS, 2011a), countries with increasing GE herbicideand insect-resistant corn production acreage (Brookes and Barfoot, 2011). 

Farmers in the U.S. and abroad have begun to utilize BMPs to control glyphosate or other 

herbicide-resistant weeds, but these BMPs have not necessarily increased costs (Weirich et al., 

2011) such that the competitiveness of U.S. corn and trade economic environment would be 

affected. Increasing herbicide weed resistance is also occuring in other countries producing 

herbicide-resistant crops, including U.S. corn export competitors (for example, Argentina and 

Brazil (Heap, 2011)) that would likely incur increases in production cost to mitigate the 

incidence of glyphosate-resistant weeds, similar to the U.S. experience.

Stine has submited applications for regulatory approval of Maize Line HCEM485 to Canada for 

cultivation and use as food and feed. In the 2010/2011 market year, Canada imported 

approximately 58.7% of the amount of corn they exported, and imported more corn than they 

exported in the prior three years (USDA-FAS, 2012). Canada is not a major corn export 

competitor of the U.S.; in the 2010/2011 market year, Canadian corn exports equated to only 

about 3.7% of the U.S. corn exports that year (USDA-FAS, 2012).

Preferred Alternative: Trade Economic Environment

Maize Line HCEM485 is compositionally and agronomically similar to the antecedent GA21, its 

comparators and other nonregulated glyphosate-resistant corn (Stine, 2011; USDA-APHIS, 

2011b). As such, it is not expected to affect the seed, feed, or food trade any differently than 

other nonregulated glyphosate-resistant corn varieties (see Subsections 4.7.1, Domestic 

Economic Environment). As another glyphosate-resistant corn cultivar, Maize Line HCEM485 

is expected to replace other glyphosate-resistant cultivars to the extent growers find value. 

Approval of the extension request for a determination of nonregulated status of Maize Line 

HCEM485 would, therefore, not likely increase the U.S. supply of corn that may affect trade. As 

discussed above, other countries are increasing their production of herbicide-resistant corn, 

including glyphosate-resistant cultivars, and are becoming significant export competitors to U.S. 

corn trade. Because the U.S. and other countries already have access to other glyphosateresistant corn cultivars, and Maize Line HCEM485 presents another option of glyphosateresistant corn, its availability only to U.S. producers would not likely significantly impact the 

economic trade environment. As noted above, Stine has submitted applications to Canada for 

import clearance and production approval of Maize Line HCEM485 (Potter, 2011a, personal 

communication); however, Canada is not a major U.S. corn export competitor. 

As discussed in Subsection 4.4.2, Plants Communities, the cultivation of Maize Line HCEM485 

would not change the development of glyphosate-resistant weeds nor affect the BMPs to control 

glyphosate-resistant weeds any differently than other nonregulated glyphosate-resistant corn. 

These BMPs would not necessarily increase costs such that the competitiveness of U.S. corn and 
92

trade economic environment would be affected, as the increased costs may be offset by increased 

yields (Weirich et al., 2011). 

As discussed under the No Action Alternative, global corn export markets respond to many 

factors, including consumer perception of GE crops and derived products. As another 

glyphosate-resistant corn cultivar, the availability of Maize Line HCEM485 for production in the 

U.S. would not likely affect foreign consumer perception of GE corn products or those global 

forces shaping the U.S. corn trade economic environment. 

Impacts to the trade economic environment from an extension of a determination of nonregulated 

status to Maize Line HCEM485 would be similar to the No Action Alternative.
93

5 CUMULATIVE IMPACTS

5.1 Assumptions Used for Cumulative Impacts Analysis

Cumulative effects have been analyzed for each environmental issue assessed in Section 4, 

Environmental Consequences. The cumulative effects analysis is focused on the incremental 

impacts of the Preferred Alternative taken in consideration with related activities including past, 

present, and reasonably foreseeable future actions. Certain aspects of this product and its 

cultivation would be no different between the alternatives; those instances are described below. 

In this analysis, if there are no direct or indirect impacts identified for a resource area, then 

APHIS assumes there can be no cumulative impacts. Where it is not possible to quantify 

impacts, APHIS provides a qualitative assessment of potential cumulative impacts. APHIS 

considered the potential for Maize Line HCEM485 to extend the range of corn production 

and affect the conversion of land to agricultural purposes. Stine’s studies demonstrate 

Maize Line HCEM485 is similar in its growth habit, agronomic properties, disease 

susceptibility, and composition to its antecedent GA21, its control group cultivars, other 

nonregulated varieties of glyphosate-resistant corn, and other GE and non-GE corn (Stine, 

2011; USDA-APHIS, 2011b). As such, its cultural requirements would be no different than 

those of other corn or provided by the areas in which corn is currently cultivated. As 

presented in Subsection 2.1.1, Acreage and Area of Corn Production, the majority of corn 

cultivated in the U.S. is herbicide-resistant, most of which is glyphosate-resistant (Duke and 

Powles, 2009; USDA-ERS, 2011a). Nonregulated Maize Line HCEM485 could replace 

other commercially available glyphosate-resistant corn varieties without requiring 

cultivation of new, natural lands. As such, land use changes associated with extending a 

determination of nonregulated status to Maize Line HCEM485 are not expected to be any 

different than those associated with the cultivation of other corn cultivars. Accordingly, 

although the preferred alternative would allow for new plantings of Maize Line HCEM485 to 

occur anywhere in the U.S., APHIS will focus the analysis of cumulative impacts to the areas in 

the U.S. that currently support corn production. 

Potential reasonably foreseeable cumulative effects are analyzed under the assumption that 

farmers have used in the past and would continue to use reasonable, commonly accepted BMPs

for their chosen system and varieties during agricultural corn production. APHIS recognizes, 

however, that not all farmers will use such BMPs; thus, the cumulative impact analysis will also 

make the assumption that not all farmers would do so. Stine has indicated it is not necessary to

change the use pattern of glyphosate on the glyphosate-resistant Maize Line HCEM485 variety; 

hence, APHIS will use current glyphosate labels as the basis for its potential past, present, and 

reasonably foreseeable impacts from the use of and exposure to glyphosate assessment. APHIS 

assumes growers of Maize Line HCEM485 will adhere to the EPA-registered uses and EPAapproved labels for all pesticides applied to this crop. 

As part of the cumulative impacts analysis, APHIS will assume that Maize Line HCEM485

would likely be combined with commercially available herbicide- and insect-resistant varieties 

of corn as a reasonably foreseeable future action. Crop varieties that contain more than one GE 

trait, known as a “stacked” hybrid, are currently found in agricultural production and in the 

marketplace. Maize Line HCEM485 would likely be combined with non-GE and GE corn 

varieties through traditional breeding techniques (Potter, 2011b). Stacking of nonregulated GE 
94

crop varieties using traditional breeding techniques is common practice and is not regulated by 

APHIS. Stacking could involve combining Maize Line HCEM485 with other corn varieties 

having GE traits such as herbicide, insect, and/or drought resistance, which are no longer subject 

to the regulatory requirements of 7 CFR part 340 or the plant pest provisions of the Plant 

Protection Act. Such stacked varieties could provide growers with several options such as

combining several herbicides with different modes of action for control of weeds.

5.2 Cumulative Effects

5.2.1 Past and Present Actions 

In the preceding analysis, the potential impacts from an extension of a determination of 

nonregulated status to Maize Line HCEM485 were assessed. The agronomic characteristics 

evaluated for Maize Line HCEM485 encompassed the entire life cycle of the corn plant and 

included germination, seedling emergence, growth habit, vegetative vigor, days to pollen shed, 

days to maturity, and yield parameters. The compositional analysis included the major 

constituents (carbohydrates, protein, fat, and ash), minerals, vitamins, amino acids, fatty acids, 

secondary metabolites, antinutrients, phytosterols, and nutritional impact. Maize Line 

HCEM485 is agronomically and compositionally similar to its previously nonregulated 

antecedent GA21, as well as other GE and non-GE corn varieties (Stine, 2011; USDA-APHIS, 

2011b). As a result, the potential impacts under the Preferred Alternative for all the resource 

areas analyzed would be the same as those described for the No Action Alternative. 

The Preferred Alternative is not expected to directly cause a measurable change in agricultural 

acreage or area devoted to conventional or GE corn cultivation or corn grown for seed in the 

U.S. (see Subsections 4.2.1, Acreage and Area of Corn Production, and 4.2.3, Corn Seed 

Production). The majority of corn grown in the U.S. is GE and herbicide resistant (USDA-ERS,

2011a). Long-term projections show planted corn maintaining between approximately 90 and 92 

million acres a year through 2020, about the same as the 92.3 million acres planted to corn in 

2011 (USDA-NASS, 2011b; USDA-OCE, 2011). Because Maize Line HCEM485 is another 

glyphosate-resistant corn cultivar agronomically and compositionally similar to other 

commercially available glyphosate-resistant corn cultivars, and herbicide-resistant corn is 

currently approximately 72% of all planted corn and most U.S. corn is glyphosate-resistant, it is 

expected Maize Line HCEM485 would replace other similar cultivars without expanding the 

acreage or area of corn production. Additionally, no anticipated changes to the availability of 

GE and non-GE corn varieties on the market are anticipated.

Based upon recent trends, adding GE varieties to the market is not related to the ability of 

organic production systems to maintain their market share (see Subsection 4.2.4, Organic Corn 

Production). As described above, the majority of corn in 2011 was GE and herbicide resistant 

(USDA-ERS, 2011a). Since 1994, 27 GE corn events or lines have been determined by APHIS 

to be no longer subject to the regulatory requirements of 7 CFR part 340 or the plant pest 

provisions of the Plant Protection Act (USDA-APHIS, 2012). U.S. organic corn production 

acreage grew 83% from 32,650 acres in 1995 to 194,637 acres in 2008, and remained at about 

0.2% of total U.S. corn acreage from 2005 to 2008 (USDA-ERS, 2010a). Availability of another 

GE glyphosate-resistant corn variety, such as Maize Line HCEM485 under the Preferred 

Alternative, is not expected to impact the organic production of corn any differently than other 

GE varieties currently being grown. 
95

Extending a determination of nonregulated status to Maize Line HCEM485 is not expected to 

result in changes to current corn cropping practices. Studies conducted by Stine demonstrate 

that, in terms of agronomic characteristics and cultivation practices, Maize Line HCEM485 is 

similar to other corn varieties currently grown (Stine, 2011; USDA-APHIS, 2011b). 

Consequently, no changes to current corn cropping practices such as tillage, crop rotation, or 

agricultural inputs associated with the adoption of Maize Line HCEM485 are expected (see 

Subsection 4.2.2, Agronomic Practices). 

Extending a determination of nonregulated status to Maize Line HCEM485 would have the same 

impacts to water, soil, air quality, and climate change as that of nonregulated glyphosate-resistant 

corn varieties presently available. Agronomic practices that have the potential to impact soil, 

water and air quality, and climate change such as tillage, agricultural inputs (fertilizers and 

pesticides), and irrigation would not change because Maize Line HCEM485 is agronomically 

similar to other glyphosate-resistant corn and other GE and non-GE corn. Other practices that 

benefit these resources, such as contouring, use of cover crops to limit the time soil is exposed to 

wind and rain, crop rotation, and windbreaks would also be the same. Because of its similarity to 

other nonregulated glyphosate-resistant corn and the fact that most cultivated corn in the U.S. is 

glyphosate resistant, adoption of Maize Line HCEM485 is expected to replace other similar 

cultivars without changing the acreage or area of corn production that could impact water, soil, 

air quality, and climate change. 

The impacts of the Preferred Alternative to animal and plants communities, microorganisms, and 

biodiversity would be no different than that experienced under the No Action Alternative. Maize 

Line HCEM485 is both agronomically and compositionally similar to its antecedent GA21 and 

other nonregulated glyphosate-resistant corn; thus, it would not require any different agronomic 

practices to cultivate, and does not represent a safety or increased weediness risk any differently 

than other currently available glyphosate-resistant corn. Availability of Maize Line HCEM485 

would not impact the development of glyphosate-resistant weeds or the trend to broaden weed 

management tactics to affect control over herbicide-resistant weeds, as it is expected to replace 

other glyphosate-resistant cultivars without expanding the acreage or area of corn production or 

changing the application rates of glyphosate. 

The potential impacts from the use of herbicides under the Preferred Alternative would be the 

same as those of the No Action Alternative. The methods of application and use rate for 

herbicides to be applied to Maize Line HCEM485 would not change from those already 

approved for use on other nonregulated glyphosate-resistant corn cultivars. The total amount of 

the mix of herbicides that could be applied to Maize Line HCEM485 would be limited by the 

authorized EPA-registered uses and the total application amount allowed by law. Glyphosate 

and other pesticides are registered by the EPA under FIFRA and are reviewed and reregistered 

every 15 years to assess potential toxicity and environmental impact. In order to be registered 

for use, a pesticide must be able to be used without unreasonable risks to people or the 

environment. Pesticide residue tolerances for glyphosate and other herbicides and pesticides are 

listed in 40 CFR §180.364 and include acceptable concentrations for corn grain and forage. In 

addition, the safety precautions and EPA-labeled instructions for the application of pesticides 

would not change under the Preferred Alternative, ensuring continued human health and worker 

safety. 
96

There are no differences in the potential for gene flow and weediness under the Preferred Action 

Alternative. Only limited populations of sexually compatible relatives of domesticated corn are 

found within the U.S.; hence, there is not a significant risk of gene movement between corn and 

its wild or weedy maize relatives (US-EPA, 2011b). Additionally, corn seed does not possess 

the characteristics for efficient seed-mediated gene flow, does not establish wild or feral 

populations, and is dependent on human cultivation for survival (OECD, 2003; Doebley, 2004). 

Maize Line HCEM485 is similar to other glyphosate-resistant corn varieties. The risk of gene 

flow and weediness of Maize Line HCEM485 is no greater than that of other nonregulated 

glyphosate-resistant corn varieties.

Food and feed derived from GE corn must be in compliance with all applicable legal and 

regulatory requirements and may undergo a voluntary consultation process with the FDA prior to 

release onto the market to identify and discuss relevant safety, nutritional, or other regulatory 

issues regarding the bioengineered food. Maize Line HCEM485 is expected to have no toxic 

effect to human health or livestock. Stine submitted a safety and nutritional assessment of food 

and feed derived from Maize Line HCEM485 to the FDA in December 2010 and their decision is 

pending. It will be posted on the FDA website Final Biotechnology Consultations 

http://www.fda.gov/Food /Biotechnology/Submissions/ucm225108.htm when completed. A 

food safety evaluation of the EPSPS protein for the GA21 corn variety was completed by the 

FDA (BNF No. 000051) on February 10, 1998, which found no safety concerns (US-FDA, 

1998a). In addition, the potential environmental impacts from the cultivation of glyphosateresistant corn varieties have been thoroughly evaluated by APHIS (see 

http://www.aphis.usda.gov/biotechnology /not_reg.html). APHIS has determined there would be 

no significant risk to biological resources from the presence of the EPSPS protein that confers 

glyphosate resistance in Maize Line HCEM485, which is the same protein found in nonregulated 

glyphosate-resistant corn cultivars in commerce today. No change in food and feed safety is 

expected to occur under the Preferred Alternative.

SinceMaize Line HCEM485 is glyphosate-resistant, it would directly compete with the market 

share of other glyphosate-resistant corn varieties. Based on its similarity to other nonregulated 

corn cultivars, Maize Line HCEM485 would likely replace other glyphosate-resistant corn 

cultivars without impacting corn acreage or production area that may affect domestic markets.

Additionally, since Maize Line HCEM485 is agronomically and compositionally similar to other 

commercially available corn, there would be no changes to agronomic inputs or practices that 

may impact on-farm costs for corn producers or the domestic economic environment, including 

the organic corn market. As mentioned above, Maize Line HCEM485 would not likely impact 

the development or treatment of herbicide-resistant weeds or their associated costs in crop losses 

or methods to affect control. No changes to the domestic economic environment are expected to 

occur under the Preferred Alternative.

Similarly, Maize Line HCEM485 is not expected to affect the seed, feed, or food trade any 

differently than other nonregulated glyphosate-resistant corn varieties. Other countries already 

have access to and are increasing their production of glyphosate-resistant corn varieties and are 

becoming significant export competitors to U.S. corn trade. Maize Line HCEM485 is 

compositionally and agronomically similar to other glyphosate-resistant cultivars in the 

marketplace. In summary, the potential cumulative effects regarding past and present actions 
97

combined with the Preferred Alternative have been analyzed, and no changes from the current 

baseline under the No Action Alternative would occur. 

5.2.2 Reasonably Foreseeable Actions

If a determination of nonregulated status is extended to Maize Line HCEM485, the cultivar 

would likely be combined (stacked) with non-GE and GE corn varieties using traditional 

breeding techniques. Stacking of nonregulated GE crop varieties using traditional breeding 

techniques is common practice. As of 2011, corn with only herbicide-resistant traits comprised

23% of the U.S. corn grown, but a greater proportion was stacked with both herbicide- and 

insect-resistant traits (49%) (USDA-ERS, 2011a). 

Potential future stacking of Maize Line HCEM485 might include development of hybrids using 

other currently available nonregulated corn varieties expressing resistance to other herbicides, or 

resistance to select insect pests by stacking with one of the biopesticidal Bt genes. For example,

a new cultivar combining glyphosate and glufosinate resistance with insect resistance is available 

for the 2012 planting season (Monsanto, 2011b; Monsanto, 2011a). APHIS regulations under 7 

CFR part 340 do not provide for Agency oversight of stacked varieties combining GE varieties 

that are no longer regulated under 7 CFR 340 or the plant pest provisions of the Plant Protection 

Act, unless it can be positively shown that such stacked varieties are likely to pose a plant pest 

risk. Whether Maize Line HCEM485 would be stacked with any particular nonregulated GE or 

non-GE variety is unknown, as company plans and market demands play a significant role in

those business decisions. In addition, the adoption level of Maize Line HCEM485 would depend 

on the extent producers value the traits offered by stacked versions of Maize Line HCEM485 

over other available stacked corn varieties. 

The potential future development and cultivation of Maize Line HCEM485 glyphosate-resistant 

corn stacked with other herbicide-resistant, insect-resistant, and/or other GE traits is not likely to 

change the area or acreage of corn production. Despite the availability of these cultivars, corn 

production acreage is expected to remain relatively stable until 2020 (USDA-OCE, 2011). 

If Maize Line HCEM485 is stacked with other transgenic herbicide-resistant traits, depending on 

the extent of its adoption, it may contribute to sustaining conservation tillage in U.S. corn 

production that both directly and indirectly impacts water, soil, and air quality. Stacking Maize 

Line HCEM485 with other herbicide-resistant traits would enable use of a combination of 

different herbicide modes of action to be applied to corn, an approach recommended by Dill et 

al. (2008) to preserve the utility of glyphosate resistance technology. This approach has been 

proposed to mitigate the future development of herbicide-resistant weeds (Duke and Powles, 

2009), which may reduce the need for tillage for weed management (Owen, 2011), thus,

benefiting soil, water, and air quality. This could also reduce GHG emissions from soil and 

emissions from associated fuel-burning equipment that can contribute to climate change. 

Reduced tillage improves habitat value through increased water quality, availability of waste 

grain, retention of cover in fields, and increased populations of invertebrates (Brady, 2007; 

Sharpe, 2010). Similarly, stacking multiple herbicide resistance into a single cultivar may 

sustain conservation tillage rates that promote greater plant diversity in fields while retaining 

crop yields which subsequently would improve soil quality and reduce soil erosion, sustaining 

both crop and non-crop plants. 
98

Similar to other stacked varities of herbicide resistant corn, Maize Line HCEM485 stacked with 

other herbicide-resistant traits would, however, narrow the options for herbicidal management of 

volunteer corn. In crop rotations where soybean or some other broadleaf cultivar is rotated with 

corn, an approved grass herbicide could be used to control volunteer corn (Sandell et al., 2011). 

In continuous corn cropping systems with the same herbicide resistances, control becomes more 

complicated and must be accomplished through other means such as tillage (Sandell et al., 2011). 

Loux et al. (2011) recommend careful rotation planning to eliminate this potential problem. 

Maize Line HCEM485 stacked with insect-resistant traits would be no more likely to exhibit 

increased weediness characteristics than other currently available glyphosate- and insect-resistant

stacked transgenic corn cultivars. Similarly, stacked Maize Line HCEM485 is not expected to 

exhibit any gene flow characteristics different from the parent transformation events (i.e., crop

lines) that would pose a plant pest risk.

 The total amount of the mix of pesticides that may be applied to stacked varieties of Maize Line 

HCEM485 would be limited by the total application amount authorized by law, and would be no 

different than the application rate already approved for use on other stacked glyphosate-resistant 

corn cultivars. When used consistently with the label, the potential risks from the application of 

pesticides to stacked Maize Line HCEM485 varieties to physical and biological resources, as 

well as human health and safety, would not increase. In addition, there would be no changes to 

currently authorized pesticide tolerance levels for stacked varieties of Maize Line HCEM485. 

Maize Line HCEM485 would likely be stacked with insect-resistant corn varieties that express 

the Bt endotoxin. In accordance with 40 CFR part 174, all the currently nonregulated insectresistant corn varieties that contain the Bt endotoxin are exempt from the requirement of 

tolerance in feed commodities. Based on studies undertaken to assess the potential impacts of 

the Bt endotoxin to the monarch and other non-target butterflies, as well as factors such as the 

location of corn production and the characteristics of corn pollen, the EPA determined that the 

potential risk to non-target butterflies is low (US-EPA, 2002). Maize Line HCEM485 stacked 

with insect-resistant (Bt) traits would likely replace other currently nonregulated stacked 

transgenic corn varieties with herbicide and insect resistance. The adoption of stacked Maize 

Line HCEM485 would be contingent on the extent growers see value in the traits expressed in 

comparison to other commercially available corn cultivars with similar herbicide- and insectresistant traits.

No cumulative impacts on biological resources, human health, or animal feed are anticipated 

from the stacking of Maize Line HCEM485 with additional GE traits. Food and feed derived 

from GE corn must be in compliance with all applicable legal and regulatory requirements and

may undergo a voluntary consultation process with the FDA prior to release onto the market. All 

varieties of GE corn with which Maize Line HCEM485 may be stacked with would have 

undergone, or are expected to undergo, this process to ensure their safety as food and feed 

products.

Corn varieties with single and multiple herbicide resistance or insect resistance are already 

widely available, representing almost 72% of U.S. corn acreage in 2011. While the adoption of 

herbicide-resistant-only corn has remained relatively level and the production of insect-resistantonly corn has decreased since 2007, the adoption of stacked varieties that confer resistance to 

herbicides and insects has steadily increased from 1% of planted corn acres in 2000 to 49% in 
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2011 (USDA-ERS, 2011a). As such, it is expected that Maize Line HCEM485 corn would likely 

be stacked with insect-resistant traits and would have impacts similar to other such stacked corn 

cultivars already on the market. Agronomic practices, including inputs for production of Maize 

Line HCEM485 stacked with insect resistance, would be no different than those needed to 

cultivate other commercially available corn with the same resistances; thus, changes to on-farm 

costs for corn producers or to the U.S. domestic corn market would be unlikely. Maize Line 

HCEM485 may also be stacked with other nonregulated GE traits; however, predicting these 

potential combinations would be speculative. Overall, it is unlikely that any cumulative impact 

to the domestic economic environment would result from a stacked product consisting of Maize 

Line HCEM485 and other readily-available GE traits.

U.S. corn exports have remained relatively stable over the last decade, a period in which other 

corn varieties with stacked glyphosate and other traits have been brought to market. Global 

export markets respond to many factors and are unlikely to change with the commercial 

availability of another glyphosate-resistant corn cultivar such as Maize Line HCEM485 alone, or 

stacked with other currently available traits.

In summary, the potential for impacts as a result of Maize Line HCEM485 alone or stacked with 

other nonregulated GE or non-GE corn varieties would not result in any changes to the resources 

areas when compared to the No Action Alternative. No cumulative effects are expected from an 

extension of a determination of nonregulated status to Maize Line HCEM485, when taken in 

consideration with related activities, including past, present, and reasonably foreseeable future 

actions. 
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6 THREATENED AND ENDANGERED SPECIES 

Congress passed the ESA to prevent extinctions facing many species of fish, wildlife and plants. 

The purpose of the ESA is to conserve endangered and threatened species and the ecosystems on 

which they depend as key components of America’s heritage. To implement the ESA, the U.S. 

Fish and Wildlife Service (USFWS) works in cooperation with the National Marine Fisheries 

Service (NMFS), other Federal, State, and local agencies, Tribes, non-governmental 

organizations, and private citizens. Before a plant or animal species can receive the protection 

provided by the ESA, it must first be added to the Federal list of threatened and endangered 

wildlife and plants.

A species is added to the list when the USFWS and/or NMFS determined it to be endangered or 

threatened because of any of the following factors:

• The present or threatened destruction, modification, or curtailment of its habitat or range;

• Overutilization for commercial, recreational, scientific, or educational purposes;

• Disease or predation;

• The inadequacy of existing regulatory mechanisms; and

• The natural or manmade factors affecting its survival.

In accordance with the ESA, once an animal or plant is added to the list, protective measures 

apply to the species and its habitat. These measures include protection from adverse effects of 

Federal activities. 

Section 7 (a)(2) of the ESA requires that a Federal agency, in consultation with the USFWS or 

NMFS, ensures that any action the agency authorizes, funds, or carries out is not likely to 

jeopardize the continued existence of a listed species or result in the destruction or adverse 

modification of designated critical habitat. It is the responsibility of the Federal agency taking 

the action to assess the effects of the agency’s action and to consult with the USFWS or NMFS if 

it is determined that the action “may affect” listed species or critical habitat. To facilitate 

APHIS’ ESA consultation process, the agency met with the USFWS from 1999 to 2003 to 

discuss factors relevant to APHIS’ regulatory authority and effects analysis for petitions for 

nonregulated status, and developed a process for conducting an effects determination consistent 

with the Plant Protection Act of 2000 (title IV of Public Law 106-224). APHIS uses this process 

to help fulfill its obligations and responsibilities under Section 7 of the ESA for biotechnology 

regulatory actions.

APHIS’ regulatory authority over GE organisms under the Plant Protection Act is limited to 

those GE organisms for which it has reason to believe might be a plant pest or those for which 

APHIS does not have sufficient information to determine that the GE organism is unlikely to 

pose a plant pest risk (Title 7, part 340.1 of the CFR). APHIS does not have authority to regulate 

the use of any herbicide, including glyphosate. After completing a plant pest risk analysis, if 

APHIS determines that Maize Line HCEM485 does not pose a plant pest risk, then Maize Line 

HCEM485 would no longer be subject to the plant pest provisions of the Plant Protection Act or 

to the regulatory requirements of 7 CFR part 340 and, therefore, APHIS must approve the 

extension request for a determination of nonregulated status. As part of its EA analysis, APHIS 

is analyzing the potential effects of Maize Line HCEM485 on the environment, including any 
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potential effects to threatened and endangered species (TES) and critical habitat. As part of this 

process, APHIS thoroughly reviews GE product information and data related to the organism 

(generally a plant species, but may also be other GE organisms). For each 

transgene(s)/transgenic plant, APHIS considers the following information, data, and questions:

• A review of the biology, taxonomy, and weediness potential of the crop plant and its 

sexually compatible relatives;

• Characterization of each transgene with respect to its structure and function and the 

nature of the organism from which it was obtained;

• A determination of where the new transgene and its products (if any) are produced in the 

plant and their quantity;

• A review of the agronomic performance of the plant including disease and pest 

susceptibilities, weediness potential, and agronomic and environmental impact;

• Determination of the concentrations of known plant toxicants (if any are known in the 

plant); and

• Analysis to determine if the transgenic plant is sexually compatible with any TES or a 

host of any TES.

• Any other information that may inform the potential for an organism to pose a plant pest 

risk.

In following this review process, APHIS has evaluated the potential effects that approving an 

extension request for a determination of nonregulated status to Maize Line HCEM485 would 

have on federally-listed TES, proposed species, critical habitat, and proposed critical habitat 

occurring within the 49 corn-producing U.S. states and Puerto Rico. APHIS has reviewed 

USFWS-listed and proposed TES species for each state in which corn is commercially produced 

using the Environmental Conservation Online System (ECOS) (Accessed May 17, 2012 from 

http://ecos.fws.gov/tess_public). Appendix A lists TES found in 49 corn-producing U.S. states 

and Puerto Rico. Prior to this review, APHIS considered the potential for Maize Line HCEM485 

to extend the range of corn production and affect the conversion of land to agricultural purposes. 

Stine’s studies demonstrate Maize Line HCEM485 is similar in its growth habit, agronomic 

properties, disease susceptibility, and composition to its antecedent GA21, its control group 

cultivars, other nonregulated varieties of glyphosate-resistant corn, and other GE and non-GE 

corn (Stine, 2011; USDA-APHIS, 2011b). As such, its cultural requirements would be no 

different than those of other corn or provided by the areas in which corn is currently cultivated. 

As presented in Subsection 2.1.1, Acreage and Area of Corn Production, the majority of corn 

cultivated in the U.S. is herbicide-resistant, most of which is glyphosate-resistant (Duke and 

Powles, 2009; USDA-ERS, 2011a). Nonregulated Maize Line HCEM485 could replace other 

commercially available glyphosate-resistant corn varieties without requiring cultivation of new, 

natural lands. As such, land use changes that could decrease TES habitat from an extension of a 

determination of nonregulated status to Maize Line HCEM485 are not expected to be any 

different than those associated with the cultivation of other corn cultivars. Accordingly, this 

analysis focuses on potential TES impacts where corn is currently grown. 
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6.1 Potential Effects of Maize Line HCEM485 on TES

This section considers the potential effects of the interaction of TES and Maize Line HCEM485, 

including: (1) its potential as a host for TES species; (2) potential gene flow to TES; (3) 

consumption effects of Maize Line HCEM485 seeds and vegetation; and, (4) potential non-target 

impacts to TES, their habitat, and critical habitat from glyphosate use associated with the 

production of Maize Line HCEM485.

A review of the listed and proposed TES indicates no members of the corn genus Zea serve as a 

host plant for any Federally-protected species. There are also no listed or proposed TES plant 

species that are sexually compatible or could cross-pollinate with the Zea genus in the U.S. As 

discussed above in the analysis of gene flow and weediness, commercially grown corn varieties 

in the U.S. are not considered weeds because corn does not possess characteristics to easily 

disperse and survive without human intervention (OECD, 2003). As presented in Subsections 

4.4.2, Plants Communities, and 4.4.3, Gene Flow and Weediness, the potential for gene flow 

between Maize Line HCEM485 and sexually compatible wild teosinte relatives is low. While 

corn and various teosinte species are culturally and biologically similar, and gene exchange 

between these groups has been documented at low frequencies in Mexico, there has been no 

evidence of successful weedy species developing (US-EPA, 2011b). Based on the agronomic 

studies conducted by Stine and verified by APHIS, extending determination of nonregulated 

status to Maize Line HCEM485 does not present a plant pest risk, a risk of increased potential 

for weediness, nor an increased risk of gene flow, when compared to other currently cultivated 

corn varieties (USDA-APHIS, 2011b). 

Stine has presented information on the animal feed safety characteristics of Maize Line 

HCEM485 that could impact wildlife that may use cornfields as a food source, consuming the 

plant or insects that live on the plants. Few TES are likely to use cornfields because they do not 

provide suitable habitat; however, some species may visit agricultural fields for incidental 

feeding. Midwestern TES species that occasionally feed in farmed sites include: whooping crane 

(Grus americana), sandhill crane (Grus canadensis pulla), piping plover (Charadrius melodus), 

and interior least tern (Sterna antillarum) (USFWS, 2011a). These and other bird species may 

visit cornfields during migratory periods, but would not be present during normal farming 

operations (Krapu et al., 2004; USFWS, 2011a). The Delmarva fox squirrel (Sciurus niger 

cinereus), which inhabits mature forests of mixed hardwoods and pines, may be found adjacent 

to agricultural areas of the Delmarva Peninsula (USFWS, 2011b). The Delmarva fox squirrel 

feeds primarily on acorns, nuts, and pine seeds, but also utilizes corn in adjacent agricultural 

fields (USFWS, 2011b). The Louisiana black bear (Ursus americanus luteolus), occurring in 

Louisiana, Mississippi, and Texas (USFWS, 2011c), may occasionally forage on corn 

(Mississippi State University, No Date).

Maize Line HCEM485 presents minimal risk to TES consuming this crop. As discussed in 

Subsection 4.6, Animal Feed, there is no difference in the composition and nutritional quality of 

Maize Line HCEM485 compared with conventional corn (Stine, 2011); no expected hazards are 

associated with its consumption. The FDA has previously evaluated the safety of GE corn 

cultivars containing the EPSPS protein, which included toxicity and allergenicity assessments, 

finding no safety concern (US-FDA, 1998a). Pending results of the final biotechnology 
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consultation with the FDA, effects on TES consuming Maize Line HCEM485 would be unlikely, 

regardless of exposure.

After reviewing the possible effects of allowing the unregulated environmental release of Maize 

Line HCEM485, APHIS has not identified any stressor that could affect the reproduction, 

numbers, or distribution of a listed TES or species proposed for listing. As a result, a detailed 

exposure analysis for individual species is not necessary. APHIS also considered the potential 

effect of extending a determination of nonregulated status to Maize Line HCEM485 on 

designated critical habitat or habitat proposed for designation, and could identify no differences 

from effects that would occur from the production of other corn varieties. Corn is not considered 

a particularly competitive plant species and has been selected for domestication and cultivation 

under conditions not normally found in natural settings (US-EPA, 2011b). Corn is not sexually 

compatible with, or serves as a host species for, any listed species or species proposed for listing. 

Consumption of Maize Line HCEM485 by any listed species or species proposed for listing 

would not result in a toxic or allergic reaction. Based on these factors, APHIS has concluded 

that extending a determination of nonregulated status to Maize Line HCEM485 and the 

corresponding environmental release of this corn variety would have no effect on listed species 

or species proposed for listing, and would not affect designated habitat or habitat proposed for 

designation. Because of this “no effect” determination, consultation under Section 7(a)(2) of the 

Act, or the concurrence of the USFWS or NMFS is not required.

6.2 Potential Effects of the Use of Glyphosate

APHIS met with USFWS officials on June 15, 2011 to discuss whether APHIS has any 

obligations under the ESA regarding analyzing the impacts of herbicide use associated with all 

GE crops on TES. As a result of these joint discussions, the USFWS and APHIS have agreed 

that it is not necessary for APHIS to perform an ESA effects analysis on herbicide use associated 

either with Maize Line HCEM485 or with all GE crops currently planted because the EPA has 

both complete regulatory authority over the labeling of pesticides and the necessary technical 

expertise to assess pesticide effects on the environment under FIFRA. APHIS has no statutory 

authority to authorize or regulate the use of glyphosate, or any other herbicide, by corn growers. 

Under Part 340 regulations, APHIS only has authority to regulate Maize Line HCEM485 or any 

GE organism as long as the agency believes it may pose a plant pest risk. APHIS has no 

regulatory jurisdiction over any other risks associated with GE organisms including risks 

resulting from the use of herbicides or other pesticides on those organisms. Nevertheless, 

APHIS is aware that there may be potential environmental impacts resulting from the use of 

glyphosate on Maize Line HCEM485, including potential impacts on TES and critical habitat, 

based on assessments provided by the EPA, and in peer reviewed scientific literature. APHIS is 

providing the available information of potential environmental impacts resulting from glyphosate 

use on Maize Line HCEM485 below.

6.2.1 EPA Endangered Species Protection Program (ESPP)

On October 7, 1988, Congress enacted Public Law 100-478 to in part address the relationship 

between the ESA and EPA’s pesticide labeling program (Section 1010) by requiring EPA to 

conduct a study, and report to Congress, on ways to implement EPA’s endangered species 

pesticide labeling program in a manner that both complies with the ESA and allows people to 

continue production of agricultural food and fiber. This law provided a clear sense that Congress 
104

wanted EPA to fulfill its obligation to conserve listed species, while at the same time consider 

the needs of agriculture and other pesticide users (70 FR 66392). 

In 1988, EPA established the ESPP to meet its obligations under the ESA. The EPA’s 

Endangered Species Protection Program website (http://www.epa.gov/espp/) describes the EPA 

assessment process for endangered species. Some of the elements of that process are 

summarized below. The goal of EPA's ESPP is to carry out its responsibilities under FIFRA in 

compliance with the ESA without placing unnecessary burden on agriculture and other pesticide 

users consistent with Congress’s intent. EPA is responsible for reviewing pesticide information 

and data to determine whether a pesticide product may be registered for a particular use, 

including those uses associated with the approval of biotechnology products. As part of that 

determination, the Agency assesses whether listed endangered or threatened species or their 

designated critical habitat may be affected by use of the pesticide product. All pesticide products 

that EPA determines “may affect” a listed species or its designated critical habitat may be subject 

to the ESPP. If limitations on pesticide use are necessary to protect listed species in areas where 

a pesticide may be used, the information is related through Endangered Species Protection 

Bulletins. Bulletins identify the species of concern and the pesticide active ingredient that may 

affect the listed species. They also provide a description of the protection measures necessary to 

protect the species, and contain a county-level map showing the geographic area(s) associated 

with the protection measures, depending on the susceptibility of the species. Bulletins are 

enforceable as part of the product label (http://www.epa.gov/oppfead1/endanger/basic-info.htm).

6.2.2 EPA TES Evaluation Process

The EPA evaluates listed species and their critical habitat concerns within the context of 

pesticide registration and registration review so that when a decision is made, it fully addresses 

issues relative to listed species protection. If a risk assessment determines that use limitations 

are necessary to ensure that legal use of a pesticide will not harm listed species or their critical 

habitat, EPA may either change the terms of the pesticide registration or establish geographically 

specific pesticide use limitations (http://www.epa.gov/oppfead1/endanger/basic-info.htm).

The EPA’s review of the pesticide and its registration decision is independent of APHIS’ review 

and regulatory decisions under 7 CFR part 340. EPA does not require data or analyses 

conducted by APHIS to complete its reviews. The EPA evaluates extensive toxicity, ecological 

effects data, environmental fate, and transport and behavior data, most of which is required under 

FIFRA data requirements, to assess and determine how a pesticide will move through and break 

down in the environment. Risks to various taxa, e.g., birds, fish, invertebrates, plants and 

mammals are routinely assessed and used in EPA’s determinations of whether a pesticide may be

licensed for use in the U.S.

The EPA’s core pesticide risk assessment and regulatory processes ensure that protections are in 

place for all populations of non-target species, not just TES. The EPA has developed a 

comprehensive risk assessment process modeled after, and consistent with, EPA’s numerous 

guidelines for environmental assessments (http://www.epa.gov/oppfead1 

/endanger/consultation/ecorisk-overview.pdf). The result of an assessment, which may go 

through several refinements, is to determine whether the potential effects of a pesticide’s 

registration to a listed species will result in either a “no effect” or “may affect” determination. 

The EPA consults on determinations that “may affect” a listed species or adversely modify its 
105

critical habitat (http://www.epa.gov/oppfead1/endanger). As a result of either an assessment or 

consultation, EPA may require changes to the use conditions specified on the label of the 

product. When such changes are necessary only in specific geographic areas rather than 

nationwide to ensure protection of the listed species, EPA implements these changes through 

geographically-specific Endangered Species Protection Bulletins; otherwise, these changes are 

applied to the label for all uses of the pesticide.

6.2.3 Ecological Risks of Glyphosate

The ecological risks associated with use of glyphosate as an herbicide have been assessed several 

times since 1974 when it was first registered for use in the U.S. In addition, EPA has consulted 

with the USFWS on the effects of glyphosate on listed species and critical habitat. Findings 

from relevant ecological risk assessments and the results and status of consultations are 

summarized below.

In the June 1986 Registration Standard for glyphosate, the EPA discussed consultations with the 

USFWS on hazards to crops, rangeland, silvicultural sites, and the Houston toad which may 

result from the use of glyphosate. Because a jeopardy opinion resulted from these consultations, 

the agency imposed endangered species labeling requirements in the Registration Standard to 

mitigate the risk to endangered species.

In 1993, glyphosate was assessed by the EPA for the RED (US-EPA, 1993b). The RED 

concluded that direct risks to birds, mammals, invertebrates, and fish would be minimal. Under 

certain conditions, aquatic plants were expected to be at risk from glyphosate use. Additional 

data were needed for non-target terrestrial plants, including incident data and vegetative vigor 

testing on non-target terrestrial plants. The assessment stated that many endangered plants may 

be at risk from use of glyphosate with the registered use patterns. In addition, it was determined 

that the Houston toad may be at risk from use of glyphosate on alfalfa. The RED resulted in 

label changes to provide protection of aquatic organisms.

In 2003, the USDA’s Forest Service had a risk assessment conducted for glyphosate uses in 

Forest Service vegetation management programs (USDA-FS, 2003). For forestry uses, all 

commercial formulations of glyphosate contained the isopropylamine salt of glyphosate. 

Application rates ranged from 0.5 pounds acid equivalent per acre (lb ae/Ac) to 7 lb ae/Ac with 

the most typical at 2 lb ae/Ac. Based on the available data, the USDA concluded that the risks 

were minimal to mammals, birds, fish, amphibians, invertebrates, and aquatic plants. Risks to 

fish following application of the more toxic formulations were not considered to be high; 

however, the assessment did state that at an application rate of 7 lb ae/Ac, the acute exposures 

slightly exceeded the acute LC50

12 for a more tolerant freshwater fish and exceeded it by a factor 

of 2 for the less tolerant fish. These values were estimated from a worst-case scenario where 

there was a severe rainfall of about 7 inches over a 24-hour period in an area where runoff is 

favored. USDA did not conduct a separate assessment for amphibians. The document 

concluded the amphibian data indicated glyphosate is no more toxic to amphibians than it is to 

fish. For terrestrial plants, the assessment concluded that for relatively tolerant plants, when a 

low-boom spray is utilized as the method of application, there is no indication glyphosate would 

 12 The concentration of a toxicant in the air or water that is lethal to 50% of the test organisms within a designated 

period. The lower the LC50 value, the more lethal the compound.
106

result in damage from spray drift at distances from the application site of 25 feet or greater. For 

more sensitive plants, the distance increased to approximately 100 feet. For applications 

requiring the use of backpack-directed spray, the distances would be less. No risks to terrestrial 

plants from runoff were expected.

In 2004, the EPA issued a report, “Glyphosate Analysis of Risks to Endangered and Threatened 

Salmon and Steelhead”. The analysis included 11 Evolutionary Significant Units (ESU) - a 

population that is considered distinct for purposes of conservation - in California with one unit 

extending into southern Oregon. Much of the quantitative information presented and used was 

derived from the 1993 RED Ecological Risk Assessment. Testing was performed with 

formulated products, in addition to glyphosate alone, and included acute and chronic toxicity. 

Testing of the pure product indicate that pure glyphosate is practically non-toxic to the species 

examined. Glyphosate was moderately toxic to practically non-toxic in formulated products. 

Since this is somewhat increased over results with the pure chemical, the report concluded that it 

appears likely due to the added agents, generally surfactants. The EPA uses a variety of 

chemical fate and transport data to develop “estimated environmental concentrations” (EECs) 

from a suite of established models. The EECs were used with toxicity for the most sensitive 

species from technical grade testing of the active ingredient to develop acute risk quotients 

(RQs). The RQ analysis indicates that glyphosate applied at 5.062 pounds active ingredient per 

acre (lb ai/Ac) does not present an acute risk to endangered and threatened salmonids from direct 

effects because the calculated RQ is less than the level of concern (LOC). The primary indirect 

effect of concern would be for the food source for listed fish. The report concluded that this rate 

of application does not present indirect effects from loss of food or loss of cover, as the RQs for 

invertebrates and plants is less than the LOC. However, the assessment determined that use of 

glyphosate “may affect, but is not likely to adversely affect” the species based on acute toxicity 

to fish for uses with application rates above 5 lb ai/Ac. For uses with application rates below 5 

lb ai/Ac, the Agency determined glyphosate would have no effect on the 11 ESUs.

In 2006, the EPA assessed glyphosate for a new use on bentgrass (US-EPA, 2006a) (0.74 lb 

ai/Ac) and for new uses on Indian mulberry (noni), dry peas, lentils, garbanzo (US-EPA, 2006b),

safflower, and sunflower (US-EPA, 2006c), with the highest proposed ground application rate of 

3.73 lb ae/Ac. For all proposed new uses, the EPA concluded that there was minimal risk of 

direct acute effects to terrestrial animals (birds and mammals) and aquatic animals (fish, 

amphibians, and invertebrates) and minimal risk to terrestrial plants (both non-target and 

endangered plant species), aquatic non-vascular (algae and diatoms) and vascular (duckweed) 

plants from off-target spray drift and runoff from ground-based applications. In addition, there 

were no chronic risks to animals.

In 2008, as a part of EPA’s TES effects assessment for the California red-legged frog (CRLF),

EPA evaluated the effect of glyphosate use at rates up to 7.95 lb ae/Ac on fish, amphibians, 

aquatic invertebrates, aquatic plants, birds, mammals, and terrestrial invertebrates (US-EPA, 

2008b). This assessment determined that at the maximum application rate for in-crop 

applications of glyphosate to glyphosate-resistant corn (8 aerial applications of 0.75 lb ae/Ac and 

2 ground applications of 3.75 and 2.25 lb ae/Ac), there would be no effects of glyphosate use on 

the following taxa of TES: fish, amphibians, birds, and mammals. The EPA assessment was 

uncertain of the effects on terrestrial invertebrates, citing the potential to affect small insects at 
107

all application rates and large insects at the 7.95 lb ae/Ac acre rate which is above the maximum 

rate for glyphosate-resistant corn.

In 2010, EPA issued the memorandum Assessment of Ecological Risk for Glyphosate, potassium 

salt (Pesticide Chemical Code 103613; Chemical Abstract Service Number (CAS#) 70901-12-1) 

for Label Supplement to Add Uses on Roundup Ready Sweet Corn. Because of the potential risk 

from surfactants, a conservative estimation of risk to aquatic organisms was conducted on a 

formulation basis as well as on a glyphosate acid equivalent basis. The names and CAS numbers 

of the surfactant are proprietary and are not provided in the assessment. Instead the surfactant 

POEA mixture (CAS # 61791-26-2) was used because it has been used in glyphosate products 

and is known to be considerably more toxic to aquatic organisms than technical glyphosate. The 

assessment was completed with the assumption that the proposed surfactants are similar to 

POEA. Based on the proposed labels, the maximum application rate on a glyphosate acid 

equivalent basis is 3.71 lb ae/Ac glyphosate and on a formulation basis is 9.35 lb formulation/Ac.

The risk to fish, aquatic phase amphibians, aquatic invertebrates, aquatic plants, birds, reptiles, 

terrestrial phase amphibians, mammals, terrestrial invertebrates, and terrestrial plants was 

analyzed. The assessment concluded that there was no risk to fish, aquatic phase amphibians, 

aquatic invertebrates, aquatic plants, and mammals because the RQs did not exceed the LOCs for 

any of these groups. Because of the lack of toxicity studies for reptiles and terrestrial phase 

amphibians, birds are used as a surrogate. None of the available acute and subacute avian studies 

showed mortality so RQs were not calculated for birds. All of the terrestrial EEC values are 

lower than the highest dose/concentration tested (3.71 lb ae/Ac glyphosate), but many of the 

EECs for 20-gram birds were greater than 1/10th of that dose. For 100-gram birds, several EECs 

were greater than 1/10th of the highest dose and with the 1.15 lb ae/Ac dose applied 4 times per 

season; therefore, there is uncertainty associated with the effect to listed birds, reptiles, and 

terrestrial phase amphibians. The chronic LOC for birds (LOC = 1) was exceeded for

application to short grasses at the highest dose (3.71 lb ae/Ac glyphosate) (RQ = 1.07). 

However, because there were no effects at the highest concentrations in the bird studies and the 

RQ was only slightly greater than the LOC, the risk following chronic exposure is expected to be 

minimal. The assessment concluded that the risk to terrestrial invertebrates is negligible based 

on glyphosate’s classification as practically non-toxic to honeybees. Lastly, for listed terrestrial 

plants, the RQ is lower than the LOC at the highest application rate when applied via ground 

applications, but are exceeded for listed and non-listed monocots and dicots when aerially 

applied at this 3.71 lb ae/Ac glyphosate rate.

The EPA is currently conducting a registration review for glyphosate (US-EPA, 2009b). EPA 

plans to conduct comprehensive human health and ecological risk assessments, including an 

endangered species assessment for uses and formulations of glyphosate, including risks due to 

surfactants included in formulations designated only for terrestrial applications. The EPA 

estimates completing the registration review in 2015. The ecological risk assessment planned 

during the registration review will allow EPA to determine whether glyphosate’s use has “no 

effect” on or “may affect” federally listed TES or their designated critical habitat. When an 

assessment concludes that a pesticide’s use “may affect” a listed species or its designated critical 

habitat, EPA will consult with the USFWS and/or NMFS, as appropriate, and may develop labels 

that restrict the pesticide’s use or specify certain conditions, e.g., minimum separation distances 

between areas sprayed with glyphosate-based herbicides and habitats of TES.
108

6.2.4 Potential Impacts of Glyphosate Use in the Production of Corn

Under the Preferred Alternative, Stine does not propose any change in the currently permitted 

uses of glyphosate (Stine, 2011). As discussed in Subsection 4.2.1, Acreage and Area, Maize 

Line HCEM485 would not require new natural lands to be converted to agricultural use. Corn is 

widely produced throughout 49 states; in 2011, 72% of planted corn was herbicide-resistant. As 

described in Subsection 4.2.2, Agronomic Practices, Maize Line HCEM485 also does not have 

cultural requirements different from other glyphosate-resistant corn varieties that would change 

glyphosate application rates to corn. Of the 98% of planted corn that received herbicide 

applications in 19 survey states in 2010, 66% were treated with glyphosate (USDA-NASS, 

2011c) (see Subsection 2.1.2, Agronomic Practices). As discussed in Subsection 4.2.2, 

Agronomic Practices, Maize Line HCEM485 is anticipated to replace other glyphosate-resistant 

corn cultivars and no change to the registered use of glyphosate is proposed; as such, no change 

to the use rate of glyphosate is expected as a result of extending Maize Line HCEM485 

nonregulated status. 

As discussed above, the goal of EPA's ESPP is to carry out its responsibilities under FIFRA in 

compliance with the ESA. As part of the registration and reregistration process, EPA reviews 

pesticide products to ensure they meet the requirements of FIFRA and ESA, and to assess 

whether listed endangered or threatened species or their designated critical habitat may be 

affected by use of the pesticide product. An assessment and subsequent consultation in which a 

“may affect” determination is made may require changes to the use conditions specified on the 

label of the product. States have primary authority for compliance monitoring and enforcing use 

of pesticides by the label requirements. Violators of the regulations are liable for all negative 

consequences of their actions (FIFRA 7 U.S.C. 136j (a)(2)(G) Unlawful Acts); therefore, 

growers that use glyphosate are very likely to follow its label restrictions. 

In summary, glyphosate would likely continue to be a major component of weed management in 

corn production and no changes in agronomic practices are expected as a consequence of 

extending a nonregulated determination to Maize Line HCEM485. In addition, pesticide labels 

require precautions be taken to protect TES. For these reasons, glyphosate use resulting from a 

nonregulated determination for Maize Line HCEM485 does not present an increase in potential 

impacts to TES.
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7 CONSIDERATION OF EXECUTIVE ORDERS, STANDARDS, AND 

TREATIES RELATING TO ENVIRONMENTAL IMPACTS

7.1.1 Executive Orders with Domestic Implications

The following EOs require consideration of the potential impacts of the Federal action to various 

segments of the population.

• EO 12898 (US-NARA, 2010), "Federal Actions to Address Environmental Justice in 

Minority Populations and Low-Income Populations," requires Federal agencies to 

conduct their programs, policies, and activities that substantially affect human health or 

the environment in a manner so as not to exclude persons and populations from 

participation in or benefiting from such programs. It also enforces existing statutes to 

prevent minority and low-income communities from being subjected to 

disproportionately high and adverse human health or environmental effects. 

• EO 13045, “Protection of Children from Environmental Health Risks and Safety 

Risks,” acknowledges that children may suffer disproportionately from environmental 

health and safety risks because of their developmental stage, greater metabolic activity 

levels, and behavior patterns, as compared to adults. The EO (to the extent permitted by 

law and consistent with the agency’s mission) requires each Federal agency to identify, 

assess, and address environmental health risks and safety risks that may 

disproportionately affect children.

The No Action and Preferred Alternatives were analyzed with respect to EO 12898 and EO 

13045. Neither alternative is expected to have a disproportionate adverse effect on minorities, 

low-income populations, or children. 

Available mammalian toxicity data associated with the EPSPS protein establish the safety of 

Maize Line HCEM485 and its products to humans, including minorities, low-income 

populations, and children who might be exposed to them through agricultural production and/or 

processing. No additional safety precautions would need to be taken with nonregulated Maize 

Line HCEM485. 

Human toxicity has also been thoroughly evaluated by the EPA in its development of pesticide 

labels for glyphosate (US-EPA, 1993b; US-EPA, 2009b; US-EPA, 2009c). Pesticide labels 

include use precautions and restrictions intended to protect workers and their families from 

exposures. APHIS assumes that growers will adhere to herbicide use precautions and 

restrictions. As discussed in Subsection 4.5, Human Health, the potential use of glyphosate on 

Maize Line HCEM485 at the proposed application rates would be no more than that currently 

approved for other nonregulated glyphosate-resistant corn and found by the EPA not to have 

adverse impacts to human health when used in accordance with label instructions. It is expected 

that the EPA and ERS would monitor the use of Maize Line HCEM485 to determine impacts on 

agricultural practices, such as chemical use, as they have done previously for herbicide-resistant 

products.
110

Based on these factors, an extension of a determination of nonregulated status to Maize Line 

HCEM485 is not expected to have a disproportionate adverse effect on minorities, low-income 

populations, or children.

The following EO addresses Federal responsibilities regarding the introduction and effects of 

invasive species:

• EO 1311 (US-NARA, 2010), “Invasive Species,” states that Federal agencies take action 

to prevent the introduction of invasive species, to provide for their control, and to 

minimize the economic, ecological, and human health impacts that invasive species 

cause. 

Field corn is not listed in the U.S. as a noxious weed species by the Federal government (USDANRCS, 2010b), nor is it listed as an invasive species by major invasive plant data bases 

(University of Georgia and USDOI-NPS, 2009; GRN, 2012). As discussed in Subsection 2.3.3, 

Gene Flow and Weediness, cultivated corn seed does not have the ability to survive in the wild 

and requires human involvement for seed dispersion (OECD, 2003). In addition, corn seed lacks 

dormancy, will not produce a persistent seed bank, and is large and heavy and not easily 

dispersed by wind or water (Mallory-Smith and Zapiola, 2008); therefore, the chance of corn 

becoming invasive as a result of seed dispersion is not likely. As discussed in Subsection 2.3.3, 

Gene Flow and Weediness, corn and various teosinte species are culturally and biologically 

similar, and gene exchange between these groups has been documented, no successful weedy 

species has evolved and the potential for gene flow between Z. mays and sexually compatible 

wild relatives is not considered a significant agricultural or environmental risk (US-EPA, 2011b). 

As such, the potential for a weedy species of corn to develop as a result of outcrossing with 

Maize Line HCEM485 is considered to be highly unlikely. 

Volunteer corn can become extensive in crop fields, competing with desired crops for light,

moisture, and nutrients (Wilson et al., No Date). There have been reports of some volunteer 

glyphosate-resistant corn occurring in fields, even if glyphosate-resistant corn was not planted 

the previous year, thought to be a result of transgene pollen movement (Beckie and Owen, 2007). 

While pollen mediated gene transfer can occur, as discussed in Subsection 2.3.3, Gene Flow and 

Weediness, gene flow decreases rapidly with separation distance. Recommended methods to 

control volunteer corn include using a combination of techniques such as alternating the 

glyphosate-resistant corn with non-GE crops, or with GE crop cultivars having resistance to 

herbicides with different modes of action, and then application of that herbicide post-emergence. 

For example, growers could plant LibertyLink® soybean and treat it with glufosinate (Beckie 

and Owen, 2007). Others successfully utilize graminicides to control glyphosate-resistant corn 

in crops not susceptible to the herbicide. See Subsection 2.3.2, Plants Communities, for a more 

extensive discussion on controlling volunteer corn. Non-GE corn, as well as other GE herbicideresistant corn varieties, is widely grown in the U.S. Based on historical experience with these 

varieties, and the data submitted by the developer and reviewed by APHIS, Maize Line 

HCEM485 plants are similar in fitness characteristics to other corn varieties currently grown; 

hence, they are not expected to become weedy or invasive (USDA-APHIS, 2011b).
111

The following executive order requires the protection of migratory bird populations:

• EO 13186 (US-NARA, 2010), “Responsibilities of Federal Agencies to Protect 

Migratory Birds,” states that federal agencies taking actions that have, or are likely to 

have, a measurable negative effect on migratory bird populations are directed to develop 

and implement, within two years, a Memorandum of Understanding with the Fish and 

Wildlife Service that shall promote the conservation of migratory bird populations. 

Migratory birds may be found in cornfields as corn is a nutrient-rich food source for fat synthesis 

prior to migration (Krapu et al., 2004). Several species of birds are also known to forage for 

insects and seeds found in and adjacent to cornfields (Best et al., 1990; Tremblay et al., 2001; 

Puckett et al., 2009). As discussed in Subsection 4.4.1, Animal Communities, data submitted by 

the developer indicates that levels of key nutrients, minerals, antinutrients, and secondary 

metabolites in Maize Line HCEM485 were similar to the comparators, by extension the 

antecedent GA21 variety, and other commercial corn varieties (Stine, 2011). The EPSPS protein 

that confers glyphosate resistance in GA21 (the antecedent of Maize Line HCEM485) is cornderived, and 99.3% identical to its non-herbicide-resistant corn comparators (Monsanto, 1997). 

It has been previously evaluated by the FDA, (US-FDA, 1998a). According to the consultation 

note, 

“Monsanto has concluded that corn containing transformation event 

GA21 is not materially different in composition, nutrition, and 

safety from corn currently grown, processed, marketed, and 

consumed for animal feed or human food. At this time, based on 

Monsanto's description of its data and analyses, the Agency 

considers Monsanto's consultation on corn from varieties containing 

transformation event GA21 to be complete.”

 The environmental effects associated with glyphosate are summarized in the EPA RED for the 

herbicide (US-EPA, 1993b). Testing indicates that ecological toxicity of glyphosate is no more 

than slightly toxic to birds and does not exceed the agency’s LOC (US-EPA, 1993b); however, 

in accordance with new requirements under 40 CFR part 158, acute avian oral toxicity data for a 

passerine species (perching birds) is required for the current glyphosate registration review. 

Based on these factors, it is unlikely that extending a determination of nonregulated status to 

Maize Line HCEM485 would have a negative effect on migratory bird populations.

7.1.2 International Implications

• EO 12114 (US-NARA, 2010), “Environmental Effects Abroad of Major Federal 

Actions” requires federal officials to take into consideration any potential environmental 

effects outside the U.S., its territories, and possessions that result from actions being 

taken. 

APHIS has given this EO careful consideration and does not expect a significant environmental 

impact outside the U.S. if APHIS extends a determination of nonregulated status to Maize Line 

HCEM485. All existing national and international regulatory authorities and phytosanitary 

regimes that currently apply to introductions of new corn cultivars internationally apply equally 

to those covered by an APHIS determination of nonregulated status under 7 CFR part 340. 
112

Any international trade of Maize Line HCEM485 subsequent to an extension of a determination 

of nonregulated status of the product would be fully subject to national phytosanitary 

requirements and be in accordance with phytosanitary standards developed under the 

International Plant Protection Convention (IPPC, 2010). The purpose of the IPPC “is to secure a 

common and effective action to prevent the spread and introduction of pests of plants and plant 

products and to promote appropriate measures for their control” (IPPC, 2010). The protection it 

affords extends to natural flora and plant products and includes both direct and indirect damage 

by pests, including weeds. 

The IPPC establishes a standard for the reciprocal acceptance of phytosanitary certification 

among the nations that have signed or acceded to the Convention (172 countries as of March 

2010). In April 2004, a standard for Plant Risk Analysis (PRA) of LMOs was adopted at a 

meeting of the governing body of the IPPC as a supplement to an existing standard, International 

Standard for Phytosanitary Measure No. 11 (ISPM-11, Pest Risk Analysis for Quarantine Pests). 

The standard acknowledges that all LMOs will not present a pest risk and that a determination 

needs to be made early in the PRA for importation as to whether the LMO poses a potential pest 

risk resulting from the genetic modification. APHIS pest risk assessment procedures for 

genetically engineered organisms are consistent with the guidance developed under the IPPC. In 

addition, issues that may relate to commercialization and transboundary movement of particular 

agricultural commodities produced through biotechnology are being addressed in other 

international forums and through national regulations.

The Cartagena Protocol on Biosafety is a treaty under the United Nations CBD that established a 

framework for the safe transboundary movement, with respect to the environment and 

biodiversity, of LMOs, which include those modified through biotechnology. The Protocol came 

into force on September 11, 2003, and 160 countries are Parties to it as of December 2010 (CBD, 

2010). Although the U.S. is not a party to the CBD, and thus not a party to the Cartagena 

Protocol on Biosafety, U.S. exporters will still need to comply with those regulations that 

importing countries which are Parties to the Protocol have promulgated to comply with their 

obligations. The first intentional transboundary movement of LMOs intended for environmental 

release (field trials or commercial planting) will require consent from the importing country 

under an advanced informed agreement (AIA) provision, which includes a requirement for a risk 

assessment consistent with Annex III of the Protocol and the required documentation.

LMOs imported for food, feed, or processing (FFP) are exempt from the AIA procedure, and are 

covered under Article 11 and Annex II of the Protocol. Under Article 11, Parties must post 

decisions to the Biosafety Clearinghouse database on domestic use of LMOs for FFP that may be 

subject to transboundary movement. To facilitate compliance with obligations to this protocol, 

the U.S. Government has developed a website that provides the status of all regulatory reviews 

completed for different uses of bioengineered products (NBII, 2010). These data will be 

available to the Biosafety Clearinghouse. 

APHIS continues to work toward harmonization of biosafety and biotechnology consensus 

documents, guidelines, and regulations, including within the North American Plant Protection 

Organization (NAPPO), which includes Mexico, Canada, and the U.S., and within the OECD. 

NAPPO has completed three modules of the Regional Standards for Phytosanitary Measures No. 
113

14, Importation and Release into the Environment of Transgenic Plants in NAPPO Member 

Countries (NAPPO, 2003).

APHIS also participates in the North American Biotechnology Initiative, a forum for information 

exchange and cooperation on agricultural biotechnology issues for the U.S., Mexico, and 

Canada. In addition, bilateral discussions on biotechnology regulatory issues are held regularly 

with other countries including Argentina, Brazil, Japan, China, and Korea.

7.1.3 Compliance with Clean Water Act and Clean Air Act

This EA evaluated the potential changes in corn production associated with an extension of a 

determination of nonregulated status to Maize Line HCEM485 (see Subsections 4.2.1, Acreage 

and Area, and 4.2.2, Agricultural Production of Corn) and determined that the cultivation of 

Maize Line HCEM485 would not lead to the increase in, or expand the area of, corn production 

that could impact water resources or air quality any differently than currently cultivated corn 

varieties. The herbicide resistance conferred by the genetic modification to Maize Line 

HCEM485 is not expected to result in any changes in water usage for cultivation compared to 

current corn production. As discussed in Subsections 4.3.2, Water Resources, and 4.3.3, Air 

Quality, there are no expected significant negative impacts to water resources or air quality from 

potential use of glyphosate or other pesticides associated with Maize Line HCEM485

production. Based on these analyses, APHIS concludes that an extension of a determination of 

nonregulated status to Maize Line HCEM485 would comply with the CWA and the CAA.

7.1.4 Impacts on Unique Characteristics of Geographic Areas

Extension of a determination of nonregulated status to Maize Line HCEM485 is not expected to 

impact unique characteristics of geographic areas such as parklands, prime farmlands, wetlands, 

wild and scenic areas, or ecologically critical areas.

Stine has presented results of agronomic field trials for Maize Line HCEM485 that demonstrate 

there are no differences in agronomic practices, between Maize Line HCEM485 and currently 

available glyphosate-resistant corn varieties like GA21 (Stine, 2011; USDA-APHIS, 2011b). 

The common agricultural practices that would be carried out in the cultivation of Maize Line 

HCEM485 are not expected to deviate from current practices, including the use of EPAregistered pesticides. The product is expected to be cultivated by growers on agricultural land 

currently suitable for production of corn, and is not anticipated to expand the cultivation of corn 

to new, natural areas. 

The Preferred Alternative does not propose major ground disturbances or new physical 

destruction or damage to property, or any alterations of property, wildlife habitat, or landscapes; 

moreover, no prescribed sale, lease, or transfer of ownership of any property is proposed. This 

action is limited to an extension of a determination of nonregulated status to Maize Line 

HCEM485. This action would not convert land use to nonagricultural use and, therefore, would 

have no adverse impact on prime farmland. Standard agricultural practices for land preparation, 

planting, irrigation, and harvesting of plants would be used on agricultural lands planted to 

Maize Line HCEM485, including the use of EPA-registered pesticides. The Applicant’s 

adherence to EPA label use restrictions for all pesticides is expected to mitigate potential impacts 

to the human environment. 
114

With regard to pesticide use, an extension of a determination of nonregulated status to Maize 

Line HCEM485 is not likely to result in changes to the use of glyphosate on corn, including 

application timing and rates and annual maximum allowable applications. APHIS assumes that 

the grower will closely adhere to EPA label use restrictions for glyphosate. 

Glyphosate was assessed by the EPA in 1993 and is currently under reregistration review 

scheduled for completion in 2015 (US-EPA, 2009a). Potential impacts to unique geographic 

areas have been considered by the EPA in its evaluation of glyphosate. In 1993, the EPA 

completed a reregistration analysis for glyphosate which considered human health risk and 

ecological risks associated with potential exposure to glyphosate in multiple pathways (US-EPA, 

1993b). 

As a result of court orders and settlements, an endangered species assessment evaluating the 

potential impacts of the use of glyphosate on the federally threatened CRLF is underway (USEPA, 2009b). The EPA has requested initiation of formal consultation with the USFWS under 

Section 7 of the ESA to address the potential effects of glyphosate on the CRLF (US-EPA, 

2009b). The EPA’s formal consultation request for the CRLF was based on the potential for 

direct and indirect effects due to decreases in prey items, as well as potential impacts to habitat

(See Section 6, Threatened and Endangered Species).

In 2004, the EPA made a “not likely to adversely affect” determination from the use of 

glyphosate on 11 ESUs of salmon and steelhead in California and an ESU of salmon in southern 

Oregon (US-EPA, 2004) (see Section 6, Threatened and Endangered Species). Formal 

consultation with the NMFS was initiated by EPA on October 12, 2004 to fulfill a Consent 

Decree entered into between EPA and the Californians’ for Alternatives to Toxics in regards to 

the potential effects of various pesticides usage on plants and certain threatened and endangered

salmon or steelhead species. 

While this consultation is ongoing, the EPA has allowed glyphosate to remain on the market, and 

it is approved for continued use in accordance with all label requirements. Submittals to this 

analysis can be found at the Regulations.gov website under docket designation EPA-HQ-OPP2009-0361. 

The Agency plans to conduct a comprehensive ecological risk assessment, including an 

endangered species assessment, for all uses of glyphosate and its salts (US-EPA, 2009b). 

Assessments to determine impacts on unique geographic areas include:

• An ecological risk assessment to determine whether the use of glyphosate has “no effect” 

or “may affect” federally listed TES or their designated critical habitat; and

• A spray drift buffer zone analysis to evaluate potential exposure reductions to non-target 

aquatic and terrestrial plants.

The information gathered during the ecological and endangered species risk assessment will be 

used by the EPA to make the registration review decision.

Based on these findings, including the assumption that label use restrictions are in place to 

protect unique geographic areas and that those label use restrictions are adhered to, an extension 
115

of a determination of nonregulated status to Maize Line HCEM485 is not expected to impact 

unique characteristics of geographic areas such as park lands, prime farm lands, wetlands, wild 

and scenic areas, or ecologically critical areas.

7.1.5 National Historic Preservation Act (NHPA) of 1966 as Amended 

The National Historic Preservation Act (NHPA) of 1966 and its implementing regulations (36 

CFR 800) require Federal agencies to: 1) determine whether activities they propose constitute 

"undertakings" that have the potential to cause effects on historic properties and 2) if so, to 

evaluate the effects of such undertakings on such historic resources and consult with the 

Advisory Council on Historic Preservation (i.e., State Historic Preservation Office, Tribal 

Historic Preservation Officers), as appropriate. 

APHIS’ proposed action, an extension of a determination of nonregulated status to Maize Line 

HCEM485 is not expected to adversely impact cultural resources on tribal properties. Any 

farming activity that may be taken by farmers on tribal lands would only be conducted at the 

tribe’s request; thus, the tribes would have control over any potential conflict with cultural 

resources on tribal properties.

APHIS’ Preferred Alternative would have no impact on districts, sites, highways, structures, or 

objects listed in or eligible for listing in the National Register of Historic Places, nor would it 

likely cause any loss or destruction of significant scientific, cultural, or historical resources. This 

action is limited to an extension of a determination of nonregulated status to Maize Line 

HCEM485. 

APHIS’ proposed action is not an undertaking that may directly or indirectly cause alteration in 

the character or use of historic properties protected under the NHPA. In general, common 

agricultural activities conducted under this action do not have the potential to introduce visual, 

atmospheric, or noise elements to areas in which they are used that could result in effects on the 

character or use of historic properties. For example, there is potential for increased noise on the 

use and enjoyment of a historic property during the operation of tractors and other mechanical 

equipment close to such sites. A built-in mitigating factor for this issue is that virtually all of the 

methods involved would only have temporary effects on the audible nature of a site and can be 

ended at any time to restore the audible qualities of such sites to their original condition with no 

further adverse effects. Additionally, these cultivation practices are already being conducted 

throughout the corn production regions. The cultivation of Maize Line HCEM485 is not 

expected to change any of these agronomic practices that would result in an adverse impact 

under the NHPA. 
116

8 LIST OF PREPARERS

Biotechnology Regulatory Services

David Reinhold, 

Assistant Director, Environmental 

Risks Analysis Programs

Rebecca L. Stankiewicz Gabel, Ph.D.,

Senior Environmental Protection 

Specialist, Environmental Risks 

Analysis Programs

Craig Roseland, Ph.D.,

Senior Environmental Protection 

Specialist, NEPA Unit

Geo-Marine, Inc.

Name Organization Project Role

Suzanne Bates, M.S., 

Deputy Division Manager, 

Environmental 

Geo-Marine, Inc. Quality Assurance

John Ouellette, M.S.,

Senior Program Manager

Geo-Marine, Inc. Quality Assurance

Susan Miller, M.A.,

Senior NEPA Project Manager

Geo-Marine, Inc. Project Management , Sections 1,3,5, 

Air Quality, Water Resources, Animal 

Feed 

Brian Bishop, M.S.,

NEPA Analyst

Geo-Marine, Inc. Sections 1,3,7, Soil Quality, 

Microorganisms, Weediness, Human 

Health, Endnote 

Meegan Wallace, M.S.,

Environmental Project Manager

Geo-Marine, Inc. Climate Change, Biological Diversity

Chris Lotts, B.S.,

Environmental Scientist

Geo-Marine, Inc. Animal Communities, Threatened and 

Endangered Species

Michael Owen, Ph.D.,

Agronomist/Weed Scientist

Iowa State 

University

Agricultural Production of Corn, Plants 

Communities, 

Terrance Hurley, Ph.D.,

Economist

University of 

Minnesota

Domestic Economic Environment, Trade 

Economic Environment

Stephen Moose, Ph.D.,

Corn Geneticist

Illinois State 

University

Corn Genetics Subject Matter Expert, 

Gene Flow

Phyllis Fletcher, A.D.,

Document Production Manager, 

Editor

Geo-Marine, Inc. References, EndNote, Document 

Production, Editor

Anna Banda, M.S., 

Senior Administrative Assistant, 

Environmental

Geo-Marine, Inc. Editor
117

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A-1

APPENDIX A

FEDERALLY THREATENED AND ENDANGERED SPECIES IN CORN 

PRODUCTION U.S. STATES AND PUERTO RICO
A-2

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States 

and Puerto Rico (USFWS, 2012)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

A`e Zanthoxylum dipetalum var. 

tomentosum

HI P Endangered

A`e Zanthoxylum hawaiiense HI P Endangered

A`e Zanthoxylum oahuense HI P Proposed 

Endangered

`Ahinahina Argyroxiphium sandwicense 

ssp. macrocephalum HI P Threatened

`Ahinahina Argyroxiphium sandwicense 

ssp. sandwicense HI P Endangered

`Aiakeakua, popolo Solanum sandwicense HI P Endangered

`Aiea Nothocestrum breviflorum HI P Endangered

`Aiea Nothocestrum peltatum HI P Endangered

Akekee Loxops caeruleirostris HI V Endangered

Akiapola`au 

(honeycreeper) Hemignathus munroi HI V Endangered

Akikiki Oreomystis bairdi HI V Endangered

`Akoko Chamaesyce celastroides var. 

kaenana HI P Endangered

`Akoko Chamaesyce deppeana HI P Endangered

`Akoko Chamaesyce eleanoriae HI P Endangered

`Akoko Chamaesyce herbstii HI P Endangered

`Akoko Chamaesyce kuwaleana HI P Endangered

`Akoko Chamaesyce remyi var. 

kauaiensis HI P Endangered

`Akoko Chamaesyce remyi var. remyi HI P Endangered

`Akoko Chamaesyce rockii HI P Endangered

`Akoko Euphorbia haeleeleana HI P Endangered

Alabama beach mouse Peromyscus polionotus 

ammobates AL V Endangered

Alabama canebrake 

pitcher-plant Sarracenia rubra alabamensis AL P Endangered

Alabama cavefish Speoplatyrhinus poulsoni AL V Endangered

Alabama cave shrimp Palaemonias alabamae AL I Endangered
A-3

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Alabama (=inflated) 

heelsplitter Potamilus inflatus AL, LA, MS I Threatened

Alabama lampmussel Lampsilis virescens AL, TN I Endangered

Alabama leather flower Clematis socialis AL, GA P Endangered

Alabama moccasinshell Medionidus acutissimus AL, GA, MS I Threatened

Alabama pearlshell Margaritifera marrianae AL I Proposed 

Endangered

Alabama red-belly 

turtle Pseudemys alabamensis AL, MS V Endangered

Alabama streak-sorus 

fern

Thelypteris pilosa var. 

alabamensis AL P Threatened

Alabama sturgeon Scaphirhynchus suttkusi AL V Endangered

Alameda whipsnake 

(=striped racer)

Masticophis lateralis 

euryxanthus CA V Threatened

Alamosa springsnail Tryonia alamosae NM I Endangered

Alani Melicope adscendens HI P Endangered

Alani Melicope balloui HI P Endangered

Alani Melicope christophersenii HI P Proposed 

Endangered

Alani Melicope degeneri HI P Endangered

Alani Melicope haupuensis HI P Endangered

Alani Melicope hiiakae HI P Proposed 

Endangered

Alani Melicope knudsenii HI P Endangered

Alani Melicope lydgatei HI P Endangered

Alani Melicope makahae HI P Proposed 

Endangered

Alani Melicope mucronulata HI P Endangered

Alani Melicope munroi HI P Endangered

Alani Melicope ovalis HI P Endangered

Alani Melicope pallida HI P Endangered

Alani Melicope paniculata HI P Endangered

Alani Melicope puberula HI P Endangered

Alani Melicope quadrangularis HI P Endangered
A-4

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Alani Melicope reflexa HI P Endangered

Alani Melicope saint-johnii HI P Endangered

Alani Melicope zahlbruckneri HI P Endangered

Altamaha spinymussel Elliptio spinosa GA I Endangered

Amargosa niterwort Nitrophila mohavensis CA, NV P Endangered

Amargosa vole Microtus californicus 

scirpensis CA V Endangered

Amber darter Percina antesella GA, TN V Endangered

American burying 

beetle Nicrophorus americanus

AR, KS, MA, 

MO, NE, OH, 

OK, RI, SD, TX

I Endangered

American chaffseed Schwalbea americana

AL, FL, GA, 

LA, MS, NC, 

NJ, SC, VA

P Endangered

American crocodile Crocodylus acutus FL V Threatened

American hart's-tongue 

fern

Asplenium scolopendrium var. 

americanum

AL, MI, NY, 

TN P Threatened

Anastasia Island beach 

mouse

Peromyscus polionotus 

phasma FL V Endangered

`Anaunau Lepidium arbuscula HI P Endangered

Anthony's riversnail Athearnia anthonyi AL, TN I Endangered

Antioch Dunes 

evening-primrose

Oenothera deltoides ssp. 

howellii CA P Endangered

`Anunu Sicyos alba HI P Endangered

Apache trout Oncorhynchus apache AZ V Threatened

Apalachicola rosemary Conradina glabra FL P Endangered

Appalachian elktoe Alasmidonta raveneliana NC, TN I Endangered

Appalachian 

monkeyface 

(pearlymussel)

Quadrula sparsa TN, VA I Endangered

Applegate's milk-vetch Astragalus applegatei OR P Endangered

Arizona Cliff-rose

Purshia (=Cowania) 

subintegra AZ P Endangered

Arizona hedgehog 

cactus

Echinocereus triglochidiatus 

var. arizonicus AZ P Endangered
A-5

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Arkansas fatmucket Lampsilis powellii AR I Threatened

Arkansas River shiner Notropis girardi AR, KS, NM, 

OK, TX V Threatened

Armored snail Pyrgulopsis (=Marstonia) 

pachyta AL I Endangered

Arroyo (=arroyo 

southwestern) toad

Bufo californicus 

(=microscaphus) CA V Endangered

Ash-breasted tit-tyrant Anairetes alpinus NA1 V Proposed 

Endangered

Ash-grey paintbrush Castilleja cinerea CA P Threatened

Ash Meadows 

Amargosa pupfish

Cyprinodon nevadensis 

mionectes NV V Endangered

Ash Meadows 

blazingstar Mentzelia leucophylla NV P Threatened

Ash Meadows 

gumplant Grindelia fraxino-pratensis CA, NV P Threatened

Ash Meadows ivesia Ivesia kingii var. eremica CA, NV P Threatened

Ash meadows milkvetch Astragalus phoenix CA, NV P Threatened

Ash Meadows naucorid Ambrysus amargosus NV I Threatened

Ash Meadows speckled 

dace

Rhinichthys osculus 

nevadensis NV V Endangered

Ash Meadows sunray Enceliopsis nudicaulis var. 

corrugata CA, NV P Threatened

Ashy dogweed Thymophylla tephroleuca TX P Endangered

Asplenium-leaved 

diellia Diellia erecta HI P Endangered

Atlantic salmon Salmo salar ME V Endangered

Atlantic salt marsh 

snake Nerodia clarkii taeniata FL V Threatened

Attwater's greater 

prairie-chicken Tympanuchus cupido attwateri TX V Endangered

Audubon's crested 

caracara Polyborus plancus audubonii FL V Threatened

Aupaka Isodendrion hosakae HI P Endangered
A-6

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Aupaka Isodendrion laurifolium HI P Endangered

Aupaka Isodendrion longifolium HI P Threatened

Autumn Buttercup Ranunculus aestivalis 

(=acriformis) UT P Endangered

Avon Park harebells Crotalaria avonensis FL P Endangered

`Awikiwiki Canavalia molokaiensis HI P Endangered

`Awikiwiki Canavalia napaliensis HI P Endangered

Awiwi Centaurium sebaeoides HI P Endangered

Awiwi Hedyotis cookiana HI P Endangered

Bachman's warbler 

(=wood) Vermivora bachmanii FL, SC V Endangered

Bakersfield cactus Opuntia treleasei CA P Endangered

Baker's larkspur Delphinium bakeri CA P Endangered

Banbury Springs limpet Lanx sp. ID I Endangered

Bariaco Trichilia triacantha PR P Endangered

Barneby reed-mustard Schoenocrambe barnebyi UT P Endangered

Barneby ridge-cress Lepidium barnebyanum UT P Endangered

Barton Springs 

salamander Eurycea sosorum TX V Endangered

Bay checkerspot 

butterfly Euphydryas editha bayensis CA I Threatened

Bayou darter Etheostoma rubrum MS V Threatened

Beach jacquemontia Jacquemontia reclinata FL P Endangered

Beach layia Layia carnosa CA P Endangered

Bear Valley sandwort Arenaria ursina CA P Threatened

Beautiful goetzea Goetzea elegans PR P Endangered

Beautiful pawpaw Deeringothamnus pulchellus FL P Endangered

Beautiful shiner Cyprinella formosa AZ, NM V Threatened

Bee Creek Cave 

harvestman Texella reddelli TX I Endangered

Behren's silverspot 

butterfly Speyeria zerene behrensii CA I Endangered

Beluga whale Delphinapterus leucas NA1 V Endangered
A-7

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Ben Lomond 

spineflower

Chorizanthe pungens var. 

hartwegiana CA P Endangered

Ben Lomond 

wallflower Erysimum teretifolium CA P Endangered

Big Bend gambusia Gambusia gaigei TX V Endangered

Big-leaved crownbeard Verbesina dissita CA P Threatened

Big Spring spinedace Lepidomeda mollispinis 

pratensis NV V Threatened

Birdwing pearlymussel Conradilla caelata TN, VA I Endangered

Black abalone Haliotis cracherodii NA1 I Endangered

Blackburn's sphinx 

moth Manduca blackburni HI I Endangered

Black-capped vireo Vireo atricapilla OK, TX V Endangered

Black clubshell Pleurobema curtum MS I Endangered

Black-footed ferret Mustela nigripes

AZ, CO, KS, 

MT, ND, NE, 

NM, SD, UT, 

WY

V Endangered

Black lace cactus Echinocereus reichenbachii 

var. albertii TX P Endangered

Blackline Hawaiian 

damselfly

Megalagrion nigrohamatum 

nigrolineatum HI I Proposed Endangered

Blackside dace Phoxinus cumberlandensis KY, TN, VA V Threatened

Black spored quillwort Isoetes melanospora GA, SC P Endangered

Bliss Rapids snail Taylorconcha serpenticola ID I Threatened

Blowout penstemon Penstemon haydenii NE, WY P Endangered

Blue-billed curassow Crax alberti NA1 V Proposed 

Endangered

Bluemask (=jewel) 

Darter Etheostoma sp. TN V Endangered

Blue Ridge goldenrod Solidago spithamaea NC, TN P Threatened

Blue shiner Cyprinella caerulea AL, GA, TN V Threatened

Bluetail mole skink Eumeces egregius lividus FL V Threatened

Blue whale Balaenoptera musculus CA, MA V Endangered
A-8

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Blunt-nosed leopard 

lizard Gambelia silus CA V Endangered

Bocaccio Sebastes paucispinis NA1 V Endangered

Bog (=Muhlenberg) 

turtle Clemmys muhlenbergii CT, DE, MD, NJ, NY, PA V Threatened

Bone Cave harvestman Texella reyesi TX I Endangered

Bonytail chub Gila elegans AZ, CA, CO, 

NV, UT V Endangered

Borax Lake chub Gila boraxobius OR V Endangered

Boulder darter Etheostoma wapiti AL, TN V Endangered

Bradshaw's desertparsley Lomatium bradshawii OR, WA P Endangered

Brady pincushion 

cactus Pediocactus bradyi AZ P Endangered

Braken Bat Cave 

Meshweaver Cicurina venii TX I Endangered

Braun's rock-cress Arabis perstellata KY, TN P Endangered

Braunton's milk-vetch Astragalus brauntonii CA P Endangered

Britton's beargrass Nolina brittoniana FL P Endangered

Brooksville bellflower Campanula robinsiae FL P Endangered

Brown-banded antpitta Grallaria milleri NA1 V Proposed 

Endangered

Bruneau Hot 

springsnail Pyrgulopsis bruneauensis ID I Endangered

Buena Vista Lake 

ornate shrew Sorex ornatus relictus CA V Endangered

Bull Trout Salvelinus confluentus ID, MT, NV, 

OR, WA V Threatened

Bunched arrowhead Sagittaria fasciculata NC, SC P Endangered

Bunched cory cactus Coryphantha ramillosa TX P Threatened

Burke's goldfields Lasthenia burkei CA P Endangered

Butte County 

meadowfoam

Limnanthes floccosa ssp. 

californica CA P Endangered

Cahaba shiner Notropis cahabae AL V Endangered

California clapper rail Rallus longirostris obsoletus CA V Endangered
A-9

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

California condor Gymnogyps californianus AZ, CA V Endangered

California freshwater 

shrimp Syncaris pacifica CA I Endangered

California jewelflower Caulanthus californicus CA P Endangered

California least tern Sterna antillarum browni AZ, CA V Endangered

California Orcutt grass Orcuttia californica CA P Endangered

California red-legged 

frog Rana draytonii CA V Threatened

California seablite Suaeda californica CA P Endangered

California taraxacum Taraxacum californicum CA P Endangered

California tiger 

Salamander Ambystoma californiense CA V Endangered

California tiger 

Salamander Ambystoma californiense CA V Threatened

California tiger 

Salamander (Sonoma) Ambystoma californiense CA V Endangered

Calistoga allocarya Plagiobothrys strictus CA P Endangered

Callippe silverspot 

butterfly Speyeria callippe callippe CA I Endangered

Canada Lynx Lynx canadensis

CO, ID, ME, 

MI, MN, MT, 

NH, NY, OR, 

UT, VT, WA, 

WI, WY

V Threatened

Canary Rockfish Sebastes pinniger NA1 V Threatened

Canby's dropwort Oxypolis canbyi DE, GA, MD, 

NC, SC P Endangered

Canelo Hills ladies'-

tresses Spiranthes delitescens AZ P Endangered

Capa rosa Callicarpa ampla PR P Endangered

Cape Fear shiner Notropis mekistocholas NC V Endangered

Cape Sable seaside 

sparrow

Ammodramus maritimus 

mirabilis FL V Endangered

Carolina heelsplitter Lasmigona decorata NC, SC I Endangered
A-10

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Carolina northern 

flying squirrel Glaucomys sabrinus coloratus NC, TN, VA V Endangered

Carson wandering 

skipper

Pseudocopaeodes eunus 

obscurus CA, NV I Endangered

Carter's mustard Warea carteri FL P Endangered

Carter's panicgrass Panicum fauriei var. carteri HI P Endangered

Caseys june beetle Dinacoma caseyi CA I Endangered

Catalina Island 

mountain-mahogany Cercocarpus traskiae CA P Endangered

Cave crayfish Cambarus aculabrum AR I Endangered

Cave crayfish Cambarus zophonastes AR I Endangered

Chapman 

rhododendron Rhododendron chapmanii FL P Endangered

Cheat Mountain 

salamander Plethodon nettingi WV V Threatened

Cherokee darter Etheostoma scotti GA V Threatened

Chihuahua chub Gila nigrescens NM V Threatened

Chinese Camp 

brodiaea Brodiaea pallida CA P Threatened

Chinook salmon Oncorhynchus (=Salmo) 

tshawytscha CA V Endangered

Chinook salmon Oncorhynchus (=Salmo) 

tshawytscha CA V Threatened

Chinook salmon Oncorhynchus (=Salmo) 

tshawytscha OR V Threatened

Chinook salmon Oncorhynchus (=Salmo) 

tshawytscha OR, WA V Threatened

Chinook salmon Oncorhynchus (=Salmo) 

tshawytscha WA V Endangered

Chinook salmon Oncorhynchus (=Salmo) 

tshawytscha WA V Threatened

Chipola slabshell Elliptio chipolaensis AL, FL I Threatened

Chiricahua leopard 

frog Rana chiricahuensis AZ, NM V Threatened
A-11

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Chisos Mountain 

hedgehog cactus

Echinocereus chisoensis var. 

chisoensis TX P Threatened

Chittenango ovate 

amber snail Succinea chittenangoensis NY I Threatened

Choctaw bean Villosa choctawensis AL, FL I Proposed 

Endangered

Choctawhatchee beach 

mouse

Peromyscus polionotus 

allophrys FL V Endangered

Chorro Creek bog 

thistle

Cirsium fontinale var. 

obispoense CA P Endangered

Chucky madtom Noturus crypticus TN V Endangered

Chum salmon Oncorhynchus (=Salmo) keta OR, WA V Threatened

Chum salmon Oncorhynchus (=Salmo) keta WA V Threatened

Chupacallos Pleodendron macranthum PR P Endangered

Chupadera springsnail Pyrgulopsis chupaderae NM I Proposed 

Endangered

Clara Hunt's 

milk-vetch Astragalus clarianus CA P Endangered

clay-loving wild 

buckwheat Eriogonum pelinophilum CO P ndangered

Clay phacelia Phacelia argillacea UT P Endangered

Clay reed-mustard Schoenocrambe argillacea UT P Threatened

Clay's hibiscus Hibiscus clayi HI P Endangered

Clear Creek gambusia Gambusia heterochir TX V Endangered

Clover lupine Lupinus tidestromii CA P Endangered

Clover Valley 

speckled dace

Rhinichthys osculus 

oligoporus NV V Endangered

Clubshell Pleurobema clava

IL, IN, KY, MI, 

NY, OH, PA, 

TN, WV

I Endangered

Coachella Valley 

fringe-toed lizard Uma inornata CA V Threatened

Coachella Valley 

milk-vetch

Astragalus lentiginosus var. 

coachellae CA P Endangered
A-12

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Coastal California 

gnatcatcher

Polioptila californica 

californica CA V Threatened

Coastal dunes milkvetch Astragalus tener var. titi CA P Endangered

Cobana negra Stahlia monosperma PR P Threatened

Cochise pincushion 

cactus Coryphantha robbinsorum AZ P Threatened

Coffin Cave mold 

beetle Batrisodes texanus TX I Endangered

Coho salmon Oncorhynchus (=Salmo) 

kisutch CA V Endangered

Coho salmon Oncorhynchus (=Salmo) 

kisutch CA, OR V Threatened

Coho salmon Oncorhynchus (=Salmo) 

kisutch NA1 V Threatened

Coho salmon Oncorhynchus (=Salmo) 

kisutch OR V Threatened

Cokendolpher Cave 

harvestman Texella cokendolpheri TX I Endangered

Colorado Butterfly 

plant

Gaura neomexicana var. 

coloradensis CO, NE, WY P Threatened

Colorado hookless 

Cactus Sclerocactus glaucus CO P Threatened

Colorado pikeminnow 

(=squawfish) Ptychocheilus lucius AZ, CA, CO, NM, UT V Endangered

Columbian whitetailed deerOdocoileus virginianus 

leucurus OR, WA V Endangered

Colusa grass Neostapfia colusana CA P Threatened

Comal Springs 

dryopid beetle Stygoparnus comalensis TX I Endangered

Comal Springs riffle 

beetle Heterelmis comalensis TX I Endangered

Comanche Springs 

pupfish Cyprinodon elegans TX V Endangered

Conasauga logperch Percina jenkinsi GA, TN V Endangered
A-13

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Conejo dudleya Dudleya abramsii ssp. parva CA P Threatened

Conservancy fairy 

shrimp Branchinecta conservatio CA I Endangered

Contra Costa 

goldfields Lasthenia conjugens CA P Endangered

Contra Costa 

wallflower

Erysimum capitatum var. 

angustatum

CA P Endangered

Cooke's koki`o Kokia cookei HI P Endangered

Cook's holly Ilex cookii PR P Endangered

Cook's lomatium Lomatium cookii OR P Endangered

Cooley's meadowrue Thalictrum cooleyi FL, GA, NC P Endangered

Cooley's water-willow Justicia cooleyi FL P Endangered

Coosa moccasinshell Medionidus parvulus AL, GA, TN I Endangered

Copperbelly water 

snake

Nerodia erythrogaster 

neglecta IN, MI, OH V Threatened

coqui, Llanero Eleutherodactylus 

juanariveroi PR V Proposed Endangered

Coyote ceanothus Ceanothus ferrisae CA P Endangered

Cracking pearlymussel Hemistena lata AL, KY, PA, 

TN, VA I Endangered

Crenulate lead-plant Amorpha crenulata FL P Endangered

Crested honeycreeper Palmeria dolei HI V Endangered

Crimson Hawaiian 

damselfly Megalagrion leptodemus HI I Proposed Endangered

Cui-ui Chasmistes cujus NV V Endangered

Culebra Island giant 

anole Anolis roosevelti PR V Endangered

Cumberland bean 

(pearlymussel) Villosa trabalis AL, KY, NC, TN, VA I Endangered

Cumberland darter Etheostoma susanae KY, TN V Endangered

Cumberland elktoe Alasmidonta atropurpurea KY, TN I Endangered

Cumberlandian 

combshell Epioblasma brevidens AL, KY, MS, TN, VA I Endangered
A-14

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Cumberland 

monkeyface 

(pearlymussel)

Quadrula intermedia AL, TN, VA I Endangered

Cumberland pigtoe Pleurobema gibberum TN I Endangered

Cumberland rosemary Conradina verticillata KY, TN P Threatened

Cumberland sandwort Arenaria cumberlandensis KY, TN P Endangered

Curtis pearlymussel Epioblasma florentina curtisii AR, MO I Endangered

Cushenbury 

buckwheat

Eriogonum ovalifolium var. 

vineum CA P Endangered

Cushenbury 

milk-vetch Astragalus albens CA P Endangered

Cushenbury oxytheca Oxytheca parishii var. 

goodmaniana CA P Endangered

Cylindrical lioplax 

(snail) Lioplax cyclostomaformis AL I Endangered

Dark pigtoe Pleurobema furvum AL I Endangered

Davis' green pitaya Echinocereus viridiflorus var. 

davisii TX P Endangered

DeBeque phacelia Phacelia submutica CO P Threatened

Decurrent false aster Boltonia decurrens IL, MO P Threatened

Delhi Sands flowerloving flyRhaphiomidas terminatus 

abdominalis CA I Endangered

Del Mar manzanita Arctostaphylos glandulosa 

ssp. crassifolia CA P Endangered

Delmarva Peninsula 

fox squirrel Sciurus niger cinereus DE, MD, VA V Endangered

Delta green ground 

beetle Elaphrus viridis CA I Threatened

Delta smelt Hypomesus transpacificus CA V Threatened

Deltoid spurge Chamaesyce deltoidea ssp. 

deltoidea FL P Endangered

Deseret milk-vetch Astragalus desereticus UT P Threatened

Desert dace Eremichthys acros NV V Threatened

Desert pupfish Cyprinodon macularius AZ, CA V Endangered
A-15

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Desert slender 

salamander Batrachoseps aridus CA V Endangered

Desert tortoise Gopherus agassizii AZ, CA, NV, 

UT V Threatened

Desert yellowhead Yermo xanthocephalus WY P Threatened

Devils Hole pupfish Cyprinodon diabolis NV V Endangered

Devils River minnow Dionda diaboli TX V Threatened

Diamond Head 

schiedea Schiedea adamantis HI P Endangered

Dromedary 

pearlymussel Dromus dromas AL, KY, TN, VA I Endangered

Dudley Bluffs 

bladderpod Lesquerella congesta CO P Threatened

Dudley Bluffs twinpod Physaria obcordata CO P Threatened

Dunes sagebrush lizard Sceloporus arenicolus NM, TX V Proposed 

Endangered

Duskytail darter Etheostoma percnurum KY, TN, VA V Endangered

Dwarf Bear-poppy Arctomecon humilis UT P Endangered

Dwarf-flowered 

heartleaf Hexastylis naniflora NC, SC P Threatened

Dwarf iliau Wilkesia hobdyi HI P Endangered

Dwarf lake iris Iris lacustris MI, WI P Threatened

Dwarf naupaka Scaevola coriacea HI P Endangered

Dwarf wedgemussel Alasmidonta heterodon

CT, MA, MD, 

NC, NH, NJ, 

NY, PA, VA, 

VT

I Endangered

Eastern indigo snake Drymarchon corais couperi AL, FL, GA V Threatened

Eastern prairie fringed 

orchid Platanthera leucophaea

IA, IL, IN, ME, 

MI, OH, OK, 

VA, WI

P Threatened

Eastern puma 

(=cougar)

Puma (=Felis) concolor 

couguar

NA1 V Endangered

El Dorado bedstraw Galium californicum ssp. 

sierrae CA P Endangered
A-16

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Elfin tree fern Cyathea dryopteroides PR P Endangered

Elkhorn coral Acropora palmata FL, PR I Threatened

El Segundo blue 

butterfly Euphilotes battoides allyni CA I Endangered

Encinitas baccharis Baccharis vanessae CA P Threatened

Erubia Solanum drymophilum PR P Endangered

Eskimo curlew Numenius borealis NE, OK, SD, 

TX V Endangered

Etonia rosemary Conradina etonia FL P Endangered

Etowah darter Etheostoma etowahae GA V Endangered

Eureka dune grass Swallenia alexandrae CA P Endangered

Eureka Valley 

evening-primrose

Oenothera avita ssp. 

eurekensis CA P Endangered

Everglade snail kite Rostrhamus sociabilis 

plumbeus FL V Endangered

Ewa Plains `akoko Chamaesyce skottsbergii var. 

kalaeloana HI P Endangered

Fanshell Cyprogenia stegaria

AL, IL, IN, KY, 

OH, TN, VA, 

WV

I Endangered

Fassett's locoweed Oxytropis campestris var. 

chartacea WI P Threatened

Fat pocketbook Potamilus capax AR, IL, IN, KY, 

LA, MO, MS I Endangered

Fat three-ridge 

(mussel) Amblema neislerii FL, GA I Endangered

Fender's blue butterfly Icaricia icarioides fenderi OR I Endangered

Few-flowered 

navarretia

Navarretia leucocephala ssp. 

pauciflora (=N. pauciflora) CA P Endangered

Finback whale Balaenoptera physalus

AL, CA, CT, 

DE, FL, GA, 

LA, MA, MD, 

ME, MS, NC, 

NH, NJ, NY, 

PR, RI, SC, TX, 

VA

V Endangered
A-17

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Finelined pocketbook Lampsilis altilis AL, GA, TN I Threatened

Finerayed pigtoe Fusconaia cuneolus AL, TN, VA I Endangered

Fish Slough milkvetchAstragalus lentiginosus var. 

piscinensis CA P Threatened

Flat pebblesnail Lepyrium showalteri AL I Endangered

Flat pigtoe Pleurobema marshalli AL, MS I Endangered

Flat-spired threetoothed Snail Triodopsis platysayoides WV I Threatened

Flattened musk turtle Sternotherus depressus AL V Threatened

Fleshy owl's-clover Castilleja campestris ssp. 

succulenta CA P Threatened

Florida bonamia Bonamia grandiflora FL P Threatened

Florida golden aster Chrysopsis floridana FL P Endangered

Florida grasshopper 

sparrow

Ammodramus savannarum 

floridanus FL V Endangered

Florida panther Puma (=Felis) concolor coryi FL V Endangered

Florida perforate 

cladonia Cladonia perforata FL P Endangered

Florida salt marsh vole Microtus pennsylvanicus 

dukecampbelli FL V Endangered

Florida scrub-jay Aphelocoma coerulescens FL V Threatened

Florida skullcap Scutellaria floridana FL P Threatened

Florida torreya Torreya taxifolia FL, GA P Endangered

Florida ziziphus Ziziphus celata FL P Endangered

Flying earwig Hawaiian 

damselfly Megalagrion nesiotes HI I Endangered

Fosberg's love grass Eragrostis fosbergii HI P Endangered

Foskett speckled dace Rhinichthys osculus ssp. OR V Threatened

Fountain darter Etheostoma fonticola TX V Endangered

Fountain thistle Cirsium fontinale var. 

fontinale CA P Endangered

Four-petal pawpaw Asimina tetramera FL P Endangered

Fragrant prickly-apple Cereus eriophorus var. 

fragrans FL P Endangered
A-18

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Fresno kangaroo rat Dipodomys nitratoides exilis CA V Endangered

Fringed campion Silene polypetala FL, GA P Endangered

Frosted Flatwoods 

salamander Ambystoma cingulatum FL, GA, SC V Threatened

Furbish lousewort Pedicularis furbishiae ME P Endangered

Fuzzy pigtoe Pleurobema strodeanum AL, FL I Proposed 

Threatened

Gambel's watercress Rorippa gambellii CA P Endangered

Garber's spurge Chamaesyce garberi FL P Threatened

Garrett's mint Dicerandra christmanii FL P Endangered

Gaviota tarplant Deinandra increscens ssp. 

villosa CA P Endangered

Gentian pinkroot Spigelia gentianoides AL, FL P Endangered

Gentner's fritillary Fritillaria gentneri CA, OR P Endangered

Georgia pigtoe Pleurobema hanleyianum AL, GA, TN I Endangered

Giant garter snake Thamnophis gigas CA V Threatened

Giant kangaroo rat Dipodomys ingens CA V Endangered

Gila chub Gila intermedia AZ, NM V Endangered

Gila topminnow (incl. 

Yaqui) Poeciliopsis occidentalis AZ, NM V Endangered

Gila trout Oncorhynchus gilae AZ, NM V Threatened

Godfrey's butterwort Pinguicula ionantha FL P Threatened

Golden-cheeked 

warbler (=wood) Dendroica chrysoparia TX V Endangered

Golden coqui Eleutherodactylus jasperi PR V Threatened

Golden Paintbrush Castilleja levisecta OR, WA P Threatened

Golden sedge Carex lutea NC P Endangered

Goldline darter Percina aurolineata AL, GA V Threatened

Gopher tortoise Gopherus polyphemus AL, LA, MS V Threatened

Government Canyon 

bat cave meshweaver Cicurina vespera TX I Endangered

Government Canyon 

bat cave spider Neoleptoneta microps TX I Endangered
A-19

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Gowen cypress Cupressus goveniana ssp. 

goveniana CA P Threatened

Graham beardtongue Penstemon grahamii CO, UT P Proposed 

Threatened

Gray bat Myotis grisescens

AL, AR, FL, 

GA, IL, IN, KS, 

KY, MO, MS, 

NC, OK, TN, 

VA, WV

V Endangered

Gray wolf Canis lupus

CO, MI, ND, 

NE, NM, NV, 

OR, SD, UT, 

WA, WI

V Endangered

Greenback cutthroat 

trout Oncorhynchus clarki stomias CO, UT V Threatened

Green blossom 

(pearlymussel)

Epioblasma torulosa 

gubernaculum TN, VA I Endangered

Greene's tuctoria Tuctoria greenei CA P Endangered

Green pitcher-plant Sarracenia oreophila AL, GA, NC, 

TN

P Endangered

Green sea turtle Chelonia mydas

AL, CA, CT, 

DE, GA, HI, 

LA, MA, MD, 

ME, MS, NC, 

NH, NJ, NY, 

OR, PR, RI, SC, 

TX, UM, VA, 

WA

V Threatened

Green sea turtle Chelonia mydas FL V Endangered

Grizzly bear Ursus arctos horribilis ID, MT, WA, 

WY V Threatened

Guadalupe fur seal Arctocephalus townsendi CA V Threatened

Guajon Eleutherodactylus cooki PR V Threatened

Gulf Coast jaguarundi Herpailurus (=Felis) 

yagouaroundi cacomitli TX V Endangered

Gulf moccasinshell Medionidus penicillatus AL, FL, GA I Endangered
A-20

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Gulf sturgeon Acipenser oxyrinchus desotoi AL, FL, LA, MS V Threatened

Guthrie's (=Pyne's) 

ground-plum Astragalus bibullatus TN P Endangered

Gypsum wildbuckwheat Eriogonum gypsophilum NM P Threatened

Haha Cyanea acuminata HI P Endangered

Haha Cyanea asarifolia HI P Endangered

Haha Cyanea calycina HI P Proposed 

Endangered

Haha Cyanea copelandii ssp. 

copelandii HI P Endangered

Haha Cyanea copelandii ssp. 

haleakalaensis HI P Endangered

Haha Cyanea dolichopoda HI P Endangered

Haha Cyanea dunbarii HI P Endangered

Haha Cyanea eleeleensis HI P Endangered

Haha Cyanea glabra HI P Endangered

Haha Cyanea grimesiana ssp. 

grimesiana HI P Endangered

Haha Cyanea grimesiana ssp. obatae HI P Endangered

Haha Cyanea hamatiflora ssp. 

carlsonii HI P Endangered

Haha Cyanea hamatiflora ssp. 

hamatiflora HI P Endangered

Haha Cyanea humboldtiana HI P Endangered

Haha Cyanea kolekoleensis HI P Endangered

Haha Cyanea koolauensis HI P Endangered

Haha Cyanea kuhihewa HI P Endangered

Haha Cyanea lanceolata HI P Proposed 

Endangered

Haha Cyanea lobata HI P Endangered

Haha Cyanea longiflora HI P Endangered

Haha Cyanea macrostegia ssp. 

gibsonii HI P Endangered

Haha Cyanea mannii HI P Endangered
A-21

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Haha Cyanea mceldowneyi HI P Endangered

Haha Cyanea pinnatifida HI P Endangered

Haha Cyanea platyphylla HI P Endangered

Haha Cyanea procera HI P Endangered

Haha Cyanea recta HI P Threatened

Haha Cyanea remyi HI P Endangered

Haha Cyanea shipmanii HI P Endangered

Haha Cyanea stictophylla HI P Endangered

Haha Cyanea st.-johnii HI P Endangered

Haha Cyanea superba HI P Endangered

Haha Cyanea truncata HI P Endangered

Haha Cyanea undulata HI P Endangered

Hairy Orcutt grass Orcuttia pilosa CA P Endangered

Hairy rattleweed Baptisia arachnifera GA P Endangered

Haiwale Cyrtandra paliku HI P Endangered

Ha`iwale Cyrtandra crenata HI P Endangered

Ha`iwale Cyrtandra dentata HI P Endangered

Ha`iwale Cyrtandra giffardii HI P Endangered

Ha`iwale Cyrtandra kaulantha HI P Proposed 

Endangered

Ha`iwale Cyrtandra limahuliensis HI P Threatened

Ha`iwale Cyrtandra munroi HI P Endangered

Ha`iwale Cyrtandra oenobarba HI P Endangered

Ha`iwale Cyrtandra polyantha HI P Endangered

Ha`iwale Cyrtandra sessilis HI P Proposed 

Endangered

Ha`iwale Cyrtandra subumbellata HI P Endangered

Ha`iwale Cyrtandra tintinnabula HI P Endangered

Ha`iwale Cyrtandra viridiflora HI P Endangered

Hala pepe Pleomele forbesii HI P Proposed 

Endangered

Hala pepe Pleomele hawaiiensis HI P Endangered
A-22

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Harperella Ptilimnium nodosum

AL, AR, GA, 

MD, NC, SC, 

VA, WV

P Endangered

Harper's beauty Harperocallis flava FL P Endangered

Hartweg's golden 

sunburst Pseudobahia bahiifolia CA P Endangered

Hau kuahiwi Hibiscadelphus giffardianus HI P Endangered

Hau kuahiwi Hibiscadelphus hualalaiensis HI P Endangered

Hau kuahiwi Hibiscadelphus woodii HI P Endangered

Hawaii akepa 

(honeycreeper) Loxops coccineus coccineus HI V Endangered

Hawaiian (='alala) 

Crow Corvus hawaiiensis HI V Endangered

Hawaiian bluegrass Poa sandvicensis HI P Endangered

Hawaiian common 

moorhen

Gallinula chloropus 

sandvicensis HI V Endangered

Hawaiian coot Fulica americana alai HI V Endangered

Hawaiian dark-rumped 

petrel

Pterodroma phaeopygia 

sandwichensis HI V Endangered

Hawaiian gardenia 

(=Na`u) Gardenia brighamii HI P Endangered

Hawaiian goose Branta (=Nesochen) 

sandvicensis HI V Endangered

Hawaiian hoary bat Lasiurus cinereus semotus HI V Endangered

Hawaiian (=koloa) 

Duck Anas wyvilliana HI V Endangered

Hawaiian (='lo) Hawk Buteo solitarius HI V Endangered

Hawaiian monk seal Monachus schauinslandi NA1 V Endangered

Hawaiian picture-wing 

fly Drosophila sharpi HI I Endangered

Hawaiian red-flowered 

geranium Geranium arboreum HI P Endangered

Hawaiian stilt Himantopus mexicanus 

knudseni HI V Endangered

Hawaiian vetch Vicia menziesii HI P Endangered
A-23

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Hawaii creeper Oreomystis mana HI V Endangered

Hawksbill sea turtle Eretmochelys imbricata

AL, CT, DE, 

FL, GA, HI, 

LA, MA, MD, 

ME, MS, NC, 

NH, NJ, NY, 

PR, RI, SC, TX, 

VA

V Endangered

Hay's Spring amphipod Stygobromus hayi DC, MD I Endangered

Heau Exocarpos luteolus HI P Endangered

Heavy pigtoe Pleurobema taitianum AL I Endangered

Heinroth's shearwater Puffinus heinrothi NA1 V Threatened

Heliotrope milk-vetch Astragalus montii UT P Threatened

Heller's blazingstar Liatris helleri NC P Threatened

Helotes mold beetle Batrisodes venyivi TX I Endangered

Hickman's potentilla Potentilla hickmanii CA P Endangered

Hidden Lake bluecurls Trichostema austromontanum 

ssp. compactum

CA P Threatened

Higgins eye 

(pearlymussel) Lampsilis higginsii IA, IL, MN, MO, SD, WI I Endangered

Highlands scrub 

hypericum Hypericum cumulicola FL P Endangered

Higo Chumbo Harrisia portoricensis PR P Threatened

Higuero de sierra Crescentia portoricensis PR P Endangered

Hiko White River 

springfish Crenichthys baileyi grandis NV V Endangered

Hilo ischaemum Ischaemum byrone HI P Endangered

Hinckley oak Quercus hinckleyi TX P Threatened

Hine's emerald 

dragonfly Somatochlora hineana IL, MI, MO, WI I Endangered

Ho`awa Pittosporum napaliense HI P Endangered

Hoffmann's rock-cress Arabis hoffmannii CA P Endangered

Hoffmann's slenderflowered giliaGilia tenuiflora ssp. 

hoffmannii CA P Endangered

Holei Ochrosia kilaueaensis HI P Endangered
A-24

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Holmgren milk-vetch Astragalus holmgreniorum AZ, UT P Endangered

Holy Ghost ipomopsis Ipomopsis sancti-spiritus NM P Endangered

Honohono Haplostachys haplostachya HI P Endangered

Hoover's spurge Chamaesyce hooveri CA P Threatened

Houghton's goldenrod Solidago houghtonii MI, NY P Threatened

Houston toad Bufo houstonensis TX V Endangered

Howell's spectacular 

thelypody

Thelypodium howellii 

spectabilis OR P Threatened

Howell's spineflower Chorizanthe howellii CA P Endangered

Huachuca water-umbel Lilaeopsis schaffneriana var. 

recurva

AZ P Endangered

Hualapai Mexican vole Microtus mexicanus 

hualpaiensis AZ V Endangered

Hulumoa Korthalsella degeneri HI P Proposed 

Endangered

Humpback chub Gila cypha AZ, CO, UT V Endangered

Humpback whale Megaptera novaeangliae

AL, CA, DE, 

FL, GA, LA, 

MA, MD, ME, 

MS, NC, NJ, 

NY, OR, RI, SC, 

TX, VA, WA

V Endangered

Hungerford's crawling 

water Beetle Brychius hungerfordi MI I Endangered

Hutton tui chub Gila bicolor ssp. OR V Threatened

Ihi`ihi Marsilea villosa HI P Endangered

Illinois cave amphipod Gammarus acherondytes IL I Endangered

Independence Valley 

speckled dace

Rhinichthys osculus 

lethoporus NV V ndangered

Indiana bat Myotis sodalis

AL, AR, FL, 

GA, IA, IL, IN, 

KY, MD, MI, 

MO, MS, NC, 

NJ, NY, OH, 

OK, PA, TN, 

VA, VT, WV

V Endangered
A-25

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Indian Knob mountain 

balm Eriodictyon altissimum CA P Endangered

Interrupted (=Georgia) 

Rocksnail Leptoxis foremani AL, GA I Endangered

Inyo California towhee Pipilo crissalis eremophilus CA V Threatened

Ione (incl. Irish Hill) 

buckwheat

Eriogonum apricum (incl. var. 

prostratum) CA P Endangered

Ione manzanita Arctostaphylos myrtifolia CA P Threatened

Iowa Pleistocene snail Discus macclintocki IA, IL I Endangered

Island barberry Berberis pinnata ssp. insularis CA P Endangered

Island bedstraw Galium buxifolium CA P Endangered

Island malacothrix Malacothrix squalida CA P Endangered

Island night lizard Xantusia riversiana CA V Threatened

Island phacelia Phacelia insularis ssp. 

insularis CA P Endangered

Island rush-rose Helianthemum greenei CA P Threatened

Ivory-billed 

woodpecker Campephilus principalis AR V Endangered

Jaguar Panthera onca AZ, NM V Endangered

James spinymussel Pleurobema collina NC, VA, WV I Endangered

Jesup's milk-vetch Astragalus robbinsii var.

jesupi NH, VT P Endangered

Johnson's seagrass Halophila johnsonii FL P Threatened

Johnston's frankenia Frankenia johnstonii TX P Endangered

Jones cycladenia Cycladenia jonesii (=humilis) AZ, UT P Threatened

June sucker Chasmistes liorus UT V Endangered

Kamakahala Labordia cyrtandrae HI P Endangered

Kamakahala Labordia helleri HI P Endangered

Kamakahala Labordia lydgatei HI P Endangered

Kamakahala Labordia pumila HI P Endangered

Kamakahala Labordia tinifolia var. 

lanaiensis HI P Endangered

Kamakahala Labordia tinifolia var. 

wahiawaensis HI P Endangered
A-26

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Kamakahala Labordia triflora HI P Endangered

Kamanomano Cenchrus agrimonioides HI P Endangered

Kanab ambersnail Oxyloma haydeni kanabensis AZ, UT I Endangered

Karner blue butterfly Lycaeides melissa samuelis

IL, IN, MI, MN, 

NH, NY, OH, 

WI

I Endangered

Kauai akialoa 

(honeycreeper) Hemignathus procerus HI V Endangered

Kauai cave amphipod Spelaeorchestia koloana HI I Endangered

Kauai cave wolf or 

pe'e pe'e maka 'ole 

spider

Adelocosa anops HI I Endangered

Kauai hau kuahiwi Hibiscadelphus distans HI P Endangered

Kauai `o`o 

(honeyeater) Moho braccatus HI V Endangered

Kauila Colubrina oppositifolia HI P Endangered

Kaulu Pteralyxia kauaiensis HI P Endangered

Kaulu Pteralyxia macrocarpa HI P Proposed 

Endangered

Kearney's blue-star Amsonia kearneyana AZ P Endangered

Keck's Checkermallow Sidalcea keckii CA P Endangered

Kemp's ridley sea 

turtle Lepidochelys kempii

AL, CT, DE, 

FL, GA, LA, 

MA, MD, MS, 

NC, NJ, NY, RI, 

SC, TX, VA

V Endangered

Kendall Warm Springs 

dace Rhinichthys osculus thermalis WY V Endangered

Kentucky cave shrimp Palaemonias ganteri KY I Endangered

Kenwood Marsh 

checker-mallow Sidalcea oregana ssp. valida CA P Endangered

Kern mallow Eremalche kernensis CA P Endangered

Kern primrose sphinx 

moth Euproserpinus euterpe CA I Threatened
A-27

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Key deer Odocoileus virginianus 

clavium FL V Endangered

Key Largo cotton 

mouse

Peromyscus gossypinus 

allapaticola FL V Endangered

Key Largo woodrat Neotoma floridana smalli FL V Endangered

Key tree cactus Pilosocereus robinii FL P Endangered

Killer whale Orcinus orca CA, OR, WA V Endangered

Kincaid's lupine

Lupinus sulphureus 

(=oreganus) ssp. kincaidii 

(=var. kincaidii)

OR, WA P Threatened

Kio`ele Hedyotis coriacea HI P Endangered

Kiponapona Phyllostegia racemosa HI P Endangered

Kirtland's warbler Dendroica kirtlandii FL, MI, SC, WI V Endangered

Kneeland Prairie 

penny-cress Thlaspi californicum CA P Endangered

Knieskern's beakedrush Rhynchospora knieskernii DE, NJ P Threatened

Knowlton's cactus Pediocactus knowltonii CO, NM P Endangered

Kodachrome 

bladderpod Lesquerella tumulosa UT P Endangered

Kohe malama 

malama o kanaloa Kanaloa kahoolawensis HI P Endangered

Koki`o Kokia drynarioides HI P Endangered

Koki`o Kokia kauaiensis HI P Endangered

Koki`o ke`oke`o Hibiscus arnottianus ssp. 

immaculatus HI P Endangered

Koki`o ke`oke`o Hibiscus waimeae ssp. 

hannerae HI P Endangered

Kolea Myrsine juddii HI P Endangered

Kolea Myrsine knudsenii HI P Endangered

Kolea Myrsine linearifolia HI P Threatened

Kolea Myrsine mezii HI P Endangered

Ko`oko`olau Bidens amplectens HI P Proposed 

Endangered
A-28

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Ko`oko`olau Bidens micrantha ssp. 

kalealaha HI P Endangered

Ko`oko`olau Bidens wiebkei HI P Endangered

Ko`oloa`ula Abutilon menziesii HI P Endangered

Kopa Hedyotis schlechtendahliana 

var. remyi

HI P Endangered

Kopiko Psychotria grandiflora HI P Endangered

Kopiko Psychotria hobdyi HI P Endangered

Koster's springsnail Juturnia kosteri NM I Endangered

Kral's water-plantain Sagittaria secundifolia AL, GA P Threatened

Kretschmarr Cave 

mold beetle Texamaurops reddelli TX I Endangered

Kuahiwi laukahi Plantago hawaiensis HI P Endangered

Kuahiwi laukahi Plantago princeps HI P Endangered

Kuawawaenohu Alsinidendron lychnoides HI P Endangered

Kuenzler hedgehog 

cactus

Echinocereus fendleri var. 

kuenzleri NM P Endangered

Kula wahine noho Isodendrion pyrifolium HI P Endangered

Kulu`i Nototrichium humile HI P Endangered

Lacy elimia (snail) Elimia crenatella AL I Threatened

La Graciosa thistle Cirsium loncholepis CA P Endangered

Laguna Beach 

liveforever Dudleya stolonifera CA P Threatened

Laguna Mountains 

skipper Pyrgus ruralis lagunae CA I Endangered

Lahontan cutthroat 

trout

Oncorhynchus clarki 

henshawi

CA, NV, OR, 

UT V Threatened

Lake County stonecrop Parvisedum leiocarpum CA P Endangered

Lakela's mint Dicerandra immaculata FL P Endangered

Lakeside daisy Hymenoxys herbacea IL, MI, OH P Threatened

Lanai sandalwood 

(=`iliahi)

Santalum freycinetianum var. 

lanaiense HI P Endangered

Lane Mountain milkvetch Astragalus jaegerianus CA P Endangered
A-29

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Lange's metalmark 

butterfly Apodemia mormo langei CA I Endangered

Large-flowered 

fiddleneck Amsinckia grandiflora CA P Endangered

Large-flowered 

skullcap Scutellaria montana GA, TN P Threatened

Large-flowered woolly 

meadowfoam

Limnanthes floccosa ssp. 

grandiflora OR P Endangered

Large-fruited sandverbena Abronia macrocarpa TX P Endangered

Large Kauai (=kamao) 

thrush Myadestes myadestinus HI V Endangered

Last Chance 

townsendia Townsendia aprica UT P Threatened

Lau `ehu Panicum niihauense HI P Endangered

Laulihilihi Schiedea stellarioides HI P Endangered

Laurel dace Phoxinus saylori TN V Endangered

Layne's butterweed Senecio layneae CA P Threatened

Laysan duck Anas laysanensis HI V Endangered

Laysan finch 

(honeycreeper) Telespyza cantans HI V Endangered

Leafy prairie-clover Dalea foliosa AL, IL, TN P Endangered

Least Bell's vireo Vireo bellii pusillus CA V Endangered

Least tern Sterna antillarum

AR, CO, IA, IL, 

IN, KS, KY, 

LA, MO, MS, 

MT, ND, NE, 

NM, OK, SD, 

TN, TX

V Endangered

Leatherback sea turtle Dermochelys coriacea

AL, CA, CT, 

DE, FL, GA, HI, 

LA, MA, MD, 

ME, MS, NC, 

NH, NJ, NY, 

OR, PR, RI, SC, 

TX, VA, WA

V Endangered
A-30

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Lee County cave 

isopod Lirceus usdagalun VA I Endangered

Leedy's roseroot Rhodiola integrifolia ssp. 

leedyi MN, NY P Threatened

Lee pincushion cactus Coryphantha sneedii var. leei NM P Threatened

lehua makanoe Lysimachia daphnoides HI P Endangered

Leon Springs pupfish Cyprinodon bovinus TX V Endangered

Leopard darter Percina pantherina AR, OK V Threatened

Lesser long-nosed bat Leptonycteris curasoae 

yerbabuenae AZ, NM V Endangered

Lewton's polygala Polygala lewtonii FL P Endangered

Light-footed clapper 

rail Rallus longirostris levipes CA V Endangered

Liliwai Acaena exigua HI P Endangered

Little Aguja (=Creek) 

pondweed Potamogeton clystocarpus TX P Endangered

Little amphianthus Amphianthus pusillus AL, GA, SC P Threatened

Little Colorado 

spinedace Lepidomeda vittata AZ V Threatened

Little Kern golden 

trout

Oncorhynchus aguabonita 

whitei CA V Threatened

Littlewing pearlymussel Pegias fabula AL, KY, NC, 

TN, VA I Endangered

Lloyd's Mariposa 

cactus Echinomastus mariposensis TX P Threatened

Loach minnow Tiaroga cobitis AZ, NM V Threatened

Loch Lomond coyote 

thistle Eryngium constancei CA P Endangered

Loggerhead sea turtle Caretta caretta

AL, CA, CT, 

DE, FL, GA, HI, 

LA, MA, MD, 

ME, MS, NC, 

NH, NJ, NY, 

OR, PR, RI, SC, 

TX, VA

V Threatened
A-31

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Loggerhead sea turtle Caretta caretta NA1 V Threatened

Lompoc yerba santa Eriodictyon capitatum CA P Endangered

Longhorn fairy shrimp Branchinecta longiantenna CA I Endangered

Longspurred mint Dicerandra cornutissima FL P Endangered

Lost River sucker Deltistes luxatus CA, OR V Endangered

Lotis blue butterfly Lycaeides argyrognomon lotis CA I Endangered

Louisiana black bear Ursus americanus luteolus LA, MS, TX V Threatened

Louisiana pearlshell Margaritifera hembeli LA I Threatened

Louisiana quillwort Isoetes louisianensis AL, LA, MS P Endangered

Lo`ulu Pritchardia affinis HI P Endangered

Lo`ulu Pritchardia kaalae HI P Endangered

Lo`ulu Pritchardia munroi HI P Endangered

Lo`ulu Pritchardia napaliensis HI P Endangered

Lo`ulu Pritchardia remota HI P Endangered

Lo`ulu Pritchardia schattaueri HI P Endangered

Lo`ulu Pritchardia viscosa HI P Endangered

Lower Keys marsh 

rabbit Sylvilagus palustris hefneri FL V Endangered

Lyon's pentachaeta Pentachaeta lyonii CA P Endangered

Lyrate bladderpod Lesquerella lyrata AL P Threatened

MacFarlane's fouro'clock Mirabilis macfarlanei ID, OR P Threatened

Madison Cave isopod Antrolana lira VA, WV I Threatened

Madla's Cave 

meshweaver Cicurina madla TX I Endangered

Magazine Mountain 

shagreen Mesodon magazinensis AR I Threatened

Maguire primrose Primula maguirei UT P Threatened

Mahoe Alectryon macrococcus HI P Endangered

Makou Peucedanum sandwicense HI P Threatened

Malheur wire-lettuce Stephanomeria malheurensis OR P Endangered

Mancos milk-vetch Astragalus humillimus CO, NM P Endangered

Mann's bluegrass Poa mannii HI P Endangered
A-32

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Many-flowered 

navarretia

Navarretia leucocephala ssp. 

plieantha CA P Endangered

Ma`oli`oli Schiedea apokremnos HI P Endangered

Ma`oli`oli Schiedea kealiae HI P Endangered

Mapele Cyrtandra cyaneoides HI P Endangered

Marbled murrelet Brachyramphus marmoratus CA, OR, WA V Threatened

Marcescent dudleya Dudleya cymosa ssp. 

marcescens

CA P Threatened

Marin dwarf-flax Hesperolinon congestum CA P Threatened

Mariposa pussypaws Calyptridium pulchellum CA P Threatened

Marsh Sandwort Arenaria paludicola CA P Endangered

Maryland darter Etheostoma sellare MD V Endangered

Masked bobwhite 

(quail) Colinus virginianus ridgwayi AZ V Endangered

Mat-forming quillwort Isoetes tegetiformans GA P Endangered

Maui akepa 

(honeycreeper) Loxops coccineus ochraceus HI V Endangered

Maui parrotbill 

(honeycreeper) Pseudonestor xanthophrys HI V Endangered

Maui remya Remya mauiensis HI P Endangered

Mauna Loa (=Ka'u) 

silversword Argyroxiphium kauense HI P Endangered

McDonald's rock-cress Arabis macdonaldiana CA, OR P Endangered

Mead's milkweed Asclepias meadii IA, IL, IN, KS, 

MO, WI P Threatened

Mehamehame Flueggea neowawraea HI P Endangered

Menzies' wallflower Erysimum menziesii CA P Endangered

Mesa Verde cactus Sclerocactus mesae-verdae CO, NM P Threatened

Metcalf Canyon 

jewelflower

Streptanthus albidus ssp. 

albidus CA P Endangered

Mexican flannelbush Fremontodendron mexicanum CA P Endangered

Mexican long-nosed 

bat Leptonycteris nivalis NM, TX V Endangered

Mexican spotted owl Strix occidentalis lucida AZ, CO, NM, 

TX, UT V Threatened
A-33

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Miami blue butterfly Cyclargus (=Hemiargus) 

thomasi bethunebakeri FL I Endangered

Miccosukee 

gooseberry Ribes echinellum FL, SC P Threatened

Michaux's sumac Rhus michauxii GA, NC, SC, 

VA P Endangered

Michigan monkeyflower Mimulus michiganensis MI P Endangered

Minnesota dwarf trout 

lily Erythronium propullans MN P Endangered

Mission blue butterfly Icaricia icarioides 

missionensis CA I Endangered

Mississippi gopher 

frog Rana capito sevosa MS V Endangered

Mississippi sandhill 

crane Grus canadensis pulla MS V Endangered

Missouri bladderpod Physaria filiformis AR, MO P Threatened

Mitchell's satyr 

butterfly

Neonympha mitchellii

mitchellii

AL, IN, MI, MS, 

OH, VA I Endangered

Moapa dace Moapa coriacea NV V Endangered

Modoc sucker Catostomus microps CA, OR V Endangered

Mohave tui chub Gila bicolor mohavensis CA V Endangered

Mohr's Barbara button Marshallia mohrii AL, GA P Threatened

Molokai creeper Paroreomyza flammea HI V Endangered

Molokai thrush Myadestes lanaiensis rutha HI V Endangered

Mona boa Epicrates monensis monensis PR V Threatened

Mona ground iguana Cyclura cornuta stejnegeri PR V Threatened

Monito gecko Sphaerodactylus micropithecus PR V Endangered

Monterey clover Trifolium trichocalyx CA P Endangered

Monterey gilia Gilia tenuiflora ssp. arenaria CA P Endangered

Monterey spineflower Chorizanthe pungens var. 

pungens

CA P Threatened

Morefield's leather 

flower Clematis morefieldii AL, TN P Endangered
A-34

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Morro Bay kangaroo 

rat

Dipodomys heermanni 

morroensis CA V Endangered

Morro manzanita Arctostaphylos morroensis CA P Threatened

Morro shoulderband 

(=Banded dune) snail Helminthoglypta walkeriana CA I Endangered

Mountain golden 

heather Hudsonia montana NC P Threatened

Mountain sweet 

pitcher-plant Sarracenia rubra ssp. jonesii NC, SC P Endangered

Mountain yellowlegged frog Rana muscosa CA V Endangered

Mount Graham red 

squirrel

Tamiasciurus hudsonicus 

grahamensis AZ V Endangered

Mount Hermon june 

beetle Polyphylla barbata CA I Endangered

Munz's onion Allium munzii CA P Endangered

Myrtle's silverspot 

butterfly Speyeria zerene myrtleae CA I Endangered

Naenae Dubautia kalalauensis HI P Endangered

Naenae Dubautia kenwoodii HI P Endangered

Na`ena`e Dubautia herbstobatae HI P Endangered

Na`ena`e Dubautia imbricata imbricata HI P Endangered

Na`ena`e Dubautia latifolia HI P Endangered

Na`ena`e Dubautia pauciflorula HI P Endangered

Na`ena`e Dubautia plantaginea 

magnifolia HI P Endangered

Na`ena`e Dubautia plantaginea ssp. 

humilis HI P Endangered

Na`ena`e Dubautia waialealae HI P Endangered

(=Na`ena`e) lo`ulu Pritchardia hardyi HI P Endangered

Nani wai`ale`ale Viola kauaiensis var. 

wahiawaensis HI P Endangered

Nanu Gardenia mannii HI P Endangered

Napa bluegrass Poa napensis CA P Endangered

Na Pali beach hedyotis Hedyotis st.-johnii HI P Endangered
A-35

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Narrow pigtoe Fusconaia escambia AL, FL I Proposed 

Threatened

Nashville crayfish Orconectes shoupi TN I Endangered

(=Native yellow 

hibiscus) ma`o hau 

hele

Hibiscus brackenridgei HI P Endangered

Navajo sedge Carex specuicola AZ, UT P Threatened

Navasota ladies'-

tresses Spiranthes parksii TX P Endangered

Nehe Lipochaeta fauriei HI P Endangered

Nehe Lipochaeta kamolensis HI P Endangered

Nehe Lipochaeta lobata var. 

leptophylla HI P Endangered

Nehe Lipochaeta micrantha HI P Endangered

Nehe Lipochaeta tenuifolia HI P Endangered

Nehe Lipochaeta waimeaensis HI P Endangered

Nellie cory cactus Coryphantha minima TX P Endangered

Nelson's checkermallow Sidalcea nelsoniana OR, WA P Threatened

Neosho madtom Noturus placidus KS, MO, OK V Threatened

Nevin's barberry Berberis nevinii CA P Endangered

Newcomb's snail Erinna newcombi HI I Threatened

Newell's Townsend's 

shearwater Puffinus auricularis newelli HI V Threatened

New Mexican ridgenosed rattlesnake Crotalus willardi obscurus AZ, NM V Threatened

Niangua darter Etheostoma nianguae MO V Threatened

Nichol's Turk's head 

cactus

Echinocactus horizonthalonius 

var. nicholii AZ P Endangered

Nihoa finch 

(honeycreeper) Telespyza ultima HI V Endangered

Nihoa millerbird (old 

world warbler) Acrocephalus familiaris kingi HI V Endangered

Nioi Eugenia koolauensis HI P Endangered

Nipomo Mesa lupine Lupinus nipomensis CA P Endangered
A-36

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

No common name Abutilon eremitopetalum HI P Endangered

No common name Abutilon sandwicense HI P Endangered

No common name Achyranthes mutica HI P Endangered

No common name Adiantum vivesii PR P Endangered

No common name Alsinidendron obovatum HI P Endangered

No common name Alsinidendron trinerve HI P Endangered

No common name Alsinidendron viscosum HI P Endangered

No common name Amaranthus brownii HI P Endangered

No common name Aristida chaseae PR P Endangered

No common name Asplenium fragile var. insulare HI P Endangered

No common name Auerodendron pauciflorum PR P Endangered

No common name Bonamia menziesii HI P Endangered

No common name Calyptranthes thomasiana PR P Endangered

No common name Catesbaea melanocarpa PR P Endangered

No common name Chamaecrista glandulosa var. 

mirabilis PR P Endangered

No common name Chamaesyce halemanui HI P Endangered

No common name Cordia bellonis PR P Endangered

No common name Cranichis ricartii PR P Endangered

No common name Cyanea purpurellifolia HI P Proposed 

Endangered

No common name Cyanea (=Rollandia) crispa HI P Endangered

No common name Cyrtandra gracilis HI P Proposed 

Endangered

No common name Cyrtandra waiolani HI P Proposed 

Endangered

No common name Daphnopsis hellerana PR P Endangered

No common name Delissea rhytidosperma HI P Endangered

No common name Delissea undulata HI P Endangered

No common name Diellia falcata HI P Endangered

No common name Diellia mannii HI P Endangered

No common name Diellia pallida HI P Endangered

No common name Diellia unisora HI P Endangered

No common name Diplazium molokaiense HI P Endangered
A-37

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

No common name Doryopteris angelica HI P Endangered

No common name Doryopteris takeuchii HI P Proposed 

Endangered

No common name Elaphoglossum serpens PR P Endangered

No common name Eugenia woodburyana PR P Endangered

No common name Gahnia lanaiensis HI P Endangered

No common name Geocarpon minimum AR, LA, MO, 

TX

P Threatened

No common name Gesneria pauciflora PR P Threatened

No common name Gouania hillebrandii HI P Endangered

No common name Gouania meyenii HI P Endangered

No common name Gouania vitifolia HI P Endangered

No common name Hedyotis degeneri HI P Endangered

No common name Hedyotis parvula HI P Endangered

No common name Hesperomannia arborescens HI P Endangered

No common name Hesperomannia arbuscula HI P Endangered

No common name Hesperomannia lydgatei HI P Endangered

No common name Ilex sintenisii PR P Endangered

No common name Keysseria (=Lagenifera) erici HI P Endangered

No common name Keysseria (=Lagenifera) 

helenae HI P Endangered

No common name Lepanthes eltoroensis PR P Endangered

No common name Leptocereus grantianus PR P Endangered

No common name Lipochaeta venosa HI P Endangered

No common name Lobelia gaudichaudii ssp. 

koolauensis HI P Endangered

No common name Lobelia monostachya HI P Endangered

No common name Lobelia niihauensis HI P Endangered

No common name Lobelia oahuensis HI P Endangered

No common name Lyonia truncata var. proctorii PR P Endangered

No common name Lysimachia filifolia HI P Endangered

No common name Lysimachia iniki HI P Endangered

No common name Lysimachia lydgatei HI P Endangered

No common name Lysimachia maxima HI P Endangered
A-38

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

No common name Lysimachia pendens HI P Endangered

No common name Lysimachia scopulensis HI P Endangered

No common name Lysimachia venosa HI P Endangered

No common name Mariscus fauriei HI P Endangered

No common name Mariscus pennatiformis HI P Endangered

No common name Mitracarpus maxwelliae PR P Endangered

No common name Mitracarpus polycladus PR P Endangered

No common name Munroidendron racemosum HI P Endangered

No common name Myrcia paganii PR P Endangered

No common name Neraudia angulata HI P Endangered

No common name Neraudia ovata HI P Endangered

No common name Neraudia sericea HI P Endangered

No common name Phyllostegia glabra var. 

lanaiensis HI P Endangered

No common name Phyllostegia hirsuta HI P Endangered

No common name Phyllostegia hispida HI P Endangered

No common name Phyllostegia kaalaensis HI P Endangered

No common name Phyllostegia knudsenii HI P Endangered

No common name Phyllostegia mannii HI P Endangered

No common name Phyllostegia mollis HI P Endangered

No common name Phyllostegia parviflora HI P Endangered

No common name Phyllostegia renovans HI P Endangered

No common name Phyllostegia velutina HI P Endangered

No common name Phyllostegia waimeae HI P Endangered

No common name Phyllostegia warshaueri HI P Endangered

No common name Phyllostegia wawrana HI P Endangered

No common name Platanthera holochila HI P Endangered

No common name Platydesma cornuta cornuta HI P Proposed 

Endangered

No common name Platydesma cornuta decurrens HI P Proposed 

Endangered

No common name Poa siphonoglossa HI P Endangered

No common name Polystichum calderonense PR P Endangered

No common name Pteris lidgatei HI P Endangered
A-39

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

No common name Remya kauaiensis HI P Endangered

No common name Remya montgomeryi HI P Endangered

No common name Sanicula mariversa HI P Endangered

No common name Sanicula purpurea HI P Endangered

No common name Schiedea attenuata HI P Endangered

No common name Schiedea haleakalensis HI P Endangered

No common name Schiedea helleri HI P Endangered

No common name Schiedea hookeri HI P Endangered

No common name Schiedea kaalae HI P Endangered

No common name Schiedea kauaiensis HI P Endangered

No common name Schiedea lydgatei HI P Endangered

No common name Schiedea membranacea HI P Endangered

No common name Schiedea nuttallii HI P Endangered

No common name Schiedea sarmentosa HI P Endangered

No common name Schiedea spergulina var. 

leiopoda HI P Endangered

No common name Schiedea spergulina var. 

spergulina HI P Threatened

No common name Schiedea verticillata HI P Endangered

No common name Schoepfia arenaria PR P Threatened

No common name Silene alexandri HI P Endangered

No common name Silene hawaiiensis HI P Threatened

No common name Silene lanceolata HI P Endangered

No common name Silene perlmanii HI P Endangered

No common name Spermolepis hawaiiensis HI P Endangered

No common name Stenogyne angustifolia 

angustifolia HI P Endangered

No common name Stenogyne bifida HI P Endangered

No common name Stenogyne campanulata HI P Endangered

No common name Stenogyne kanehoana HI P Endangered

No common name Stenogyne kealiae HI P Endangered

No common name Tectaria estremerana PR P Endangered

No common name Ternstroemia subsessilis PR P Endangered

No common name Tetramolopium arenarium HI P Endangered
A-40

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

No common name Tetramolopium filiforme HI P Endangered

No common name Tetramolopium lepidotum ssp. 

lepidotum HI P Endangered

No common name Tetramolopium remyi HI P Endangered

No common name Tetramolopium rockii HI P Threatened

No common name Tetraplasandra bisattenuata HI P Endangered

No common name Tetraplasandra flynnii HI P Endangered

No common name Tetraplasandra lydgatei HI P Proposed 

Endangered

No common name Thelypteris inabonensis PR P Endangered

No common name Thelypteris verecunda PR P Endangered

No common name Thelypteris yaucoensis PR P Endangered

No common name Trematolobelia singularis HI P Endangered

No common name Vernonia proctorii PR P Endangered

No common name Vigna o-wahuensis HI P Endangered

No common name Viola helenae HI P Endangered

No common name Viola lanaiensis HI P Endangered

No common name Viola oahuensis HI P Endangered

No common name Xylosma crenatum HI P Endangered

Noel's amphipod Gammarus desperatus NM I Endangered

Nohoanu Geranium kauaiense HI P Endangered

Nohoanu Geranium multiflorum HI P Endangered

Noonday snail Mesodon clarki nantahala NC I Threatened

North American green 

sturgeon Acipenser medirostris CA, OR, WA V Threatened

North Atlantic right 

whale Eubalaena glacialis

CT, DE, FL, 

GA, MA, MD, 

ME, NC, NJ, 

NY, RI, SC, VA

V Endangered

Northeastern beach 

tiger beetle Cicindela dorsalis dorsalis MA, MD, NJ, VA I Threatened

Northeastern bulrush Scirpus ancistrochaetus

MA, MD, NH, 

NY, PA, VA, 

VT, WV

P Endangered
A-41

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Northern aplomado 

falcon Falco femoralis septentrionalis TX V Endangered

Northern Idaho ground 

squirrel

Spermophilus brunneus 

brunneus ID V Threatened

Northern riffleshell Epioblasma torulosa rangiana IN, KY, MI, 

OH, PA, WV I Endangered

Northern spotted owl Strix occidentalis caurina CA, OR, WA V Threatened

Northern wild 

monkshood Aconitum noveboracense IA, NY, OH, WI P Threatened

North Pacific right 

whale Eubalaena japonica NA1 V Endangered

North Park phacelia Phacelia formosula CO P Endangered

Nukupu`u 

(honeycreeper) Hemignathus lucidus HI V Endangered

Oahu creeper Paroreomyza maculata HI V Endangered

Oahu elepaio Chasiempis sandwichensis 

ibidis HI V Endangered

Oahu tree snails Achatinella spp. HI I Endangered

Oahu wild coffee 

(=kopiko)

Psychotria hexandra ssp. 

oahuensis var. oahuensis HI P Proposed Endangered

Oceanic Hawaiian 

damselfly Megalagrion oceanicum HI I Proposed dangered

Ocelot Leopardus (=Felis) pardalis AZ, TX V Endangered

Ochlockonee 

moccasinshell Medionidus simpsonianus FL, GA I Endangered

Oha Delissea rivularis HI P Endangered

Oha Delissea subcordata HI P Endangered

Ohai Sesbania tomentosa HI P Endangered

`Oha wai Clermontia drepanomorpha HI P Endangered

`Oha wai Clermontia lindseyana HI P Endangered

`Oha wai Clermontia oblongifolia ssp. 

brevipes HI P Endangered

`Oha wai Clermontia oblongifolia ssp. 

mauiensis HI P Endangered

`Oha wai Clermontia peleana HI P Endangered
A-42

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

`Oha wai Clermontia pyrularia HI P Endangered

`Oha wai Clermontia samuelii HI P Endangered

`Ohe`ohe Tetraplasandra gymnocarpa HI P Endangered

Ohlone tiger beetle Cicindela ohlone CA I Endangered

Okaloosa darter Etheostoma okaloosae FL V Threatened

Okeechobee gourd Cucurbita okeechobeensis 

ssp. okeechobeensis FL P Endangered

Olive ridley sea turtle Lepidochelys olivacea CA, HI V Threatened

Olulu Brighamia insignis HI P Endangered

Opuhe Urera kaalae HI P Endangered

Orangefoot 

pimpleback 

(pearlymussel)

Plethobasus cooperianus AL, IL, IN, KY, 

PA, TN I Endangered

Orangenacre mucket Lampsilis perovalis AL, MS I Threatened

Orcutt's spineflower Chorizanthe orcuttiana CA P Endangered

Oregon chub Oregonichthys crameri OR V Threatened

Oregon silverspot 

butterfly Speyeria zerene hippolyta CA, OR I Threatened

Osterhout milk-vetch Astragalus osterhoutii CO P Endangered

Otay mesa-mint Pogogyne nudiuscula CA P Endangered

Otay tarplant Deinandra (=Hemizonia) 

conjugens CA P Threatened

Ouachita rock 

pocketbook Arkansia wheeleri AR, OK I Endangered

`O`u (honeycreeper) Psittirostra psittacea HI V Endangered

Oval pigtoe Pleurobema pyriforme AL, FL, GA I Endangered

Ovate clubshell Pleurobema perovatum AL, MS, TN I Endangered

Owens pupfish Cyprinodon radiosus CA V Endangered

Owens tui chub Gila bicolor ssp. snyderi CA V Endangered

Oyster mussel Epioblasma capsaeformis AL, KY, TN, 

VA I Endangered

Ozark big-eared bat Corynorhinus (=Plecotus) 

townsendii ingens AR, MO, OK V Endangered

Ozark cavefish Amblyopsis rosae AR, MO, OK V Threatened
A-43

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Ozark hellbender Cryptobranchus alleganiensis 

bishopi AR, MO V Endangered

Pacific eulachon Thaleichthys pacificus NA1 V Threatened

Pacific Hawaiian 

damselfly Megalagrion pacificum HI I Endangered

Pacific pocket mouse Perognathus longimembris 

pacificus CA V Endangered

Pagosa skyrocket Ipomopsis polyantha CO P Endangered

Pahranagat roundtail 

chub Gila robusta jordani NV V Endangered

Pahrump poolfish Empetrichthys latos NV V Endangered

Pa`iniu Astelia waialealae HI P Endangered

Painted rocksnail Leptoxis taeniata AL I Threatened

Painted snake coiled 

forest snail Anguispira picta TN I Threatened

Paiute cutthroat trout Oncorhynchus clarki seleniris CA V Threatened

Palapalai aumakua Dryopteris crinalis var. 

podosorus HI P Endangered

Pale lilliput 

(pearlymussel) Toxolasma cylindrellus AL, TN I Endangered

Palezone shiner Notropis albizonatus AL, KY V Endangered

Palila (honeycreeper) Loxioides bailleui HI V Endangered

Pallid manzanita Arctostaphylos pallida CA P Threatened

Pallid sturgeon Scaphirhynchus albus

AR, IA, IL, KS, 

KY, LA, MO, 

MS, MT, ND, 

NE, SD, TN

V Endangered

Palma de manaca Calyptronoma rivalis PR P Threatened

Palmate-bracted bird's 

beak Cordylanthus palmatus CA P Endangered

Palo colorado Ternstroemia luquillensis PR P Endangered

Palo de jazmin Styrax portoricensis PR P Endangered

Palo de nigua Cornutia obovata PR P Endangered

Palo de ramon Banara vanderbiltii PR P Endangered

Palo de rosa Ottoschulzia rhodoxylon PR P Endangered
A-44

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Palos Verdes blue 

butterfly

Glaucopsyche lygdamus 

palosverdesensis CA I Endangered

Pamakani Tetramolopium capillare HI P Endangered

Pamakani Viola chamissoniana ssp. 

chamissoniana HI P Endangered

Papala Charpentiera densiflora HI P Endangered

Papery whitlow-wort Paronychia chartacea FL P Threatened

Parachute beardtongue Penstemon debilis CO P Threatened

Pariette cactus Sclerocactus brevispinus UT P Threatened

Parish's daisy Erigeron parishii CA P Threatened

Pauoa Ctenitis squamigera HI P Endangered

Pawnee montane 

skipper Hesperia leonardus montana CO I Threatened

Peck's cave amphipod Stygobromus (=Stygonectes) 

pecki TX I Endangered

Pecos assiminea snail Assiminea pecos NM, TX I Endangered

Pecos bluntnose shiner Notropis simus pecosensis NM V Threatened

Pecos gambusia Gambusia nobilis NM, TX V Endangered

Pecos (=puzzle, 

=paradox) sunflower Helianthus paradoxus NM, TX P Threatened

Pedate checker-mallow Sidalcea pedata CA P Endangered

Peebles Navajo cactus Pediocactus peeblesianus var. 

peeblesianus AZ P Endangered

Peirson's milk-vetch Astragalus magdalenae var. 

peirsonii CA P Threatened

Pelos del diablo Aristida portoricensis PR P Endangered

Pendant kihi fern Adenophorus periens HI P Endangered

Peninsular bighorn 

sheep Ovis canadensis nelsoni CA V Endangered

Penland alpine fen 

mustard Eutrema penlandii CO P Threatened

Penland beardtongue Penstemon penlandii CO P Endangered

Pennell's bird's-beak Cordylanthus tenuis ssp. 

capillaris CA P Endangered
A-45

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Perdido Key beach 

mouse

Peromyscus polionotus 

trissyllepsis AL, FL V Endangered

Persistent trillium Trillium persistens GA, SC P Endangered

Peter's Mountain 

mallow Iliamna corei VA P Endangered

Pigeon wings Clitoria fragrans FL P Threatened

Pilo Hedyotis mannii HI P Endangered

Pilo kea lau li`i Platydesma rostrata HI P Endangered

Pima pineapple cactus Coryphantha scheeri var. 

robustispina AZ P Endangered

Pine Hill ceanothus Ceanothus roderickii CA P Endangered

Pine Hill flannelbush Fremontodendron 

californicum ssp. decumbens CA P Endangered

Pink mucket 

(pearlymussel) Lampsilis abrupta

AL, AR, IL, IN, 

KY, LA, MO, 

OH, PA, TN, 

VA, WV

I Endangered

Piping plover Charadrius melodus

AL, AR, CO, 

CT, DE, FL, IA, 

KS, LA, MA, 

MD, ME, MT, 

NC, ND, NE, 

NH, NJ, NM, 

NY, OK, RI, 

SC, SD, TX, VA

V Threatened

Piping plover Charadrius melodus

IL, IN, MI, MN, 

MS, NY, OH, 

PA, WI

V Endangered

Pismo clarkia Clarkia speciosa ssp. 

immaculata CA P Endangered

Pitcher's thistle Cirsium pitcheri IL, IN, MI, WI P Threatened

Pitkin marsh lily Lilium pardalinum ssp. 

pitkinense CA P Endangered

Plicate rocksnail Leptoxis plicata AL I Endangered

Plymouth red-bellied 

turtle

Pseudemys rubriventris 

bangsi MA V Endangered
A-46

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Po`e Portulaca sclerocarpa HI P Endangered

Point Arena mountain 

beaver Aplodontia rufa nigra CA V Endangered

Pondberry Lindera melissifolia

AL, AR, GA, 

MO, MS, NC, 

SC

P Endangered

Po`ouli (honeycreeper) Melamprosops phaeosoma HI V Endangered

Popolo ku mai Solanum incompletum HI P Endangered

Prairie bush-clover Lespedeza leptostachya IA, IL, MN, WI P Threatened

Preble's meadow 

jumping mouse Zapus hudsonius preblei CO, WY V Threatened

Presidio clarkia Clarkia franciscana CA P Endangered

Presidio manzanita Arctostaphylos hookeri var. 

ravenii CA P Endangered

Price's potato-bean Apios priceana AL, IL, KY, 

MS, TN P Threatened

Pua `ala Brighamia rockii HI P Endangered

Puerto Rican boa Epicrates inornatus PR V Endangered

Puerto Rican broadwinged hawk Buteo platypterus brunnescens PR V Endangered

Puerto Rican crested 

toad Peltophryne lemur PR V Threatened

Puerto Rican nightjar Caprimulgus noctitherus PR V Endangered

Puerto Rican parrot Amazona vittata PR V Endangered

Puerto Rican plain 

Pigeon Columba inornata wetmorei PR V Endangered

Puerto Rican sharpshinned hawk Accipiter striatus venator PR V Endangered

Puritan tiger beetle Cicindela puritana CT, MA, MD I Threatened

Purple amole Chlorogalum purpureum CA P Threatened

Purple bankclimber 

(mussel) Elliptoideus sloatianus AL, FL, GA I Threatened

Purple bean Villosa perpurpurea TN, VA I Endangered
A-47

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

purple cat's paw 

(=purple cat's paw 

pearlymussel)

Epioblasma obliquata 

obliquata

AL, KY, OH, 

TN I Endangered

Pu`uka`a Cyperus trachysanthos HI P Endangered

Pygmy fringe-tree Chionanthus pygmaeus FL P Endangered

Pygmy madtom Noturus stanauli TN V Endangered

Pygmy rabbit Brachylagus idahoensis WA V Endangered

Pygmy sculpin Cottus paulus (=pygmaeus) AL V Threatened

Quino checkerspot 

butterfly

Euphydryas editha quino (=E. 

e. wrighti) CA I Endangered

Railroad Valley 

springfish Crenichthys nevadae NV V Threatened

Rayed bean Villosa fabalis IN, MI, NY, 

OH, PA, VA I Endangered

Razorback sucker Xyrauchen texanus AZ, CA, CO, 

NM, NV, UT V Endangered

Red-cockaded 

woodpecker Picoides borealis

AL, AR, FL, 

GA, LA, MO, 

MS, NC, OK, 

SC, TX, VA

V Endangered

Red Hills salamander Phaeognathus hubrichti AL V Threatened

Red Hills vervain Verbena californica CA P Threatened

Red wolf Canis rufus FL, NC, SC V Endangered

Relict darter Etheostoma chienense KY V Endangered

Relict trillium Trillium reliquum AL, GA, SC P Endangered

Reticulated flatwoods 

salamander Ambystoma bishopi FL, GA V Endangered

Rice rat Oryzomys palustris natator FL V Endangered

Ringed map turtle Graptemys oculifera LA, MS V Threatened

Ring pink (mussel) Obovaria retusa AL, KY, PA, 

TN I Endangered

Rio Grande silvery 

minnow Hybognathus amarus NM V Endangered

Riparian brush rabbit Sylvilagus bachmani riparius CA V Endangered
A-48

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Riparian woodrat 

(=San Joaquin Valley) Neotoma fuscipes riparia CA V Endangered

Riverside fairy shrimp Streptocephalus woottoni CA I Endangered

Roan Mountain bluet Hedyotis purpurea var. 

montana NC, TN P Endangered

Roanoke logperch Percina rex VA V Endangered

Robber Baron cave 

meshweaver Cicurina baronia TX I Endangered

Robust (incl. Scotts 

Valley) spineflower

Chorizanthe robusta (incl. 

vars. robusta and hartwegii) CA P Endangered

Rock gnome lichen Gymnoderma lineare NC, SC, TN, 

VA P Endangered

Roseate tern Sterna dougallii dougallii

CT, MA, ME, 

NC, NH, NJ, 

NY, RI, VA

V Endangered

Roseate tern Sterna dougallii dougallii FL, NC, PR, SC V Threatened

Roswell springsnail Pyrgulopsis roswellensis NM I Endangered

Rough hornsnail Pleurocera foremani AL I Endangered

Rough-leaved 

loosestrife Lysimachia asperulaefolia NC, SC P Endangered

Rough pigtoe Pleurobema plenum AL, IN, KY, 

PA, TN, VA I Endangered

rough popcornflower Plagiobothrys hirtus OR P Endangered

Rough rabbitsfoot Quadrula cylindrica strigillata TN, VA I Endangered

Round Ebonyshell Fusconaia rotulata AL, FL I Proposed 

Endangered

Round-leaved chaffflowerAchyranthes splendens var. 

rotundata HI P Endangered

Round rocksnail Leptoxis ampla AL I Threatened

Royal marstonia (snail) Pyrgulopsis ogmorhaphe TN I Endangered

Rugel's pawpaw Deeringothamnus rugelii FL P Endangered

Running buffalo clover Trifolium stoloniferum AR, IN, KY, 

MO, OH, WV P Endangered

Rush darter Etheostoma phytophilum AL V Endangered

Ruth's golden aster Pityopsis ruthii TN P Endangered
A-49

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Sacramento Mountains 

thistle Cirsium vinaceum NM P Threatened

Sacramento Orcutt 

grass

Orcuttia viscida CA P Endangered

Sacramento prickly 

poppy

Argemone pleiacantha ssp. 

pinnatisecta NM P Endangered

Saint Francis' satyr 

butterfly

Neonympha mitchellii 

francisci NC I Endangered

Salt Creek tiger beetle Cicindela nevadica lincolniana NE I Endangered

Salt marsh bird's-beak Cordylanthus maritimus ssp. 

maritimus CA P Endangered

Salt marsh harvest 

mouse Reithrodontomys raviventris CA V Endangered

San Benito eveningprimrose Camissonia benitensis CA P Threatened

San Bernardino 

bluegrass Poa atropurpurea CA P Endangered

San Bernardino 

Merriam's kangaroo rat Dipodomys merriami parvus CA V Endangered

San Bernardino 

Mountains bladderpod

Lesquerella kingii ssp. 

bernardina CA P Endangered

San Bernardino 

springsnail Pyrgulopsis bernardina AZ I Proposed Endangered

San Bruno elfin 

butterfly Callophrys mossii bayensis CA I Endangered

San Clemente Island 

broom

Lotus dendroideus ssp.

traskiae CA P Endangered

San Clemente Island 

bush-mallow Malacothamnus clementinus CA P Endangered

San Clemente Island 

indian paintbrush Castilleja grisea CA P Endangered

San Clemente Island 

larkspur

Delphinium variegatum ssp. 

kinkiense CA P Endangered

San Clemente Island 

woodland-star Lithophragma maximum CA P Endangered
A-50

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

San Clemente 

loggerhead shrike Lanius ludovicianus mearnsi CA V Endangered

San Clemente sage 

sparrow Amphispiza belli clementeae CA V Threatened

San Diego ambrosia Ambrosia pumila CA P Endangered

San Diego buttonceleryEryngium aristulatum var. 

parishii CA P Endangered

San Diego fairy 

shrimp Branchinecta sandiegonensis CA I Endangered

San Diego mesa-mint Pogogyne abramsii CA P Endangered

San Diego thornmint Acanthomintha ilicifolia CA P Threatened

Sandlace Polygonella myriophylla FL P Endangered

Sandplain gerardia Agalinis acuta CT, MA, MD, 

NY, RI P Endangered

Sand skink Neoseps reynoldsi FL V Threatened

San Francisco garter 

snake

Thamnophis sirtalis 

tetrataenia CA V Endangered

San Francisco 

lessingia

Lessingia germanorum (=L.g. 

var. germanorum) CA P Endangered

San Francisco 

manzanita Arctostaphylos franciscana CA P Proposed Endangered

San Francisco Peaks 

groundsel Senecio franciscanus AZ P Threatened

San Jacinto Valley 

crownscale Atriplex coronata var. notatior CA P Endangered

San Joaquin adobe 

sunburst Pseudobahia peirsonii CA P Threatened

San Joaquin kit fox Vulpes macrotis mutica CA V Endangered

San Joaquin Orcutt 

grass Orcuttia inaequalis CA P Threatened

San Joaquin woolythreadsMonolopia (=Lembertia) 

congdonii CA P Endangered

San Marcos gambusia Gambusia georgei TX V Endangered

San Marcos 

salamander Eurycea nana TX V Threatened
A-51

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

San Mateo thornmint Acanthomintha obovata ssp. 

duttonii CA P Endangered

San Mateo woolly 

sunflower Eriophyllum latilobum CA P Endangered

San Miguel Island fox Urocyon littoralis littoralis CA V Endangered

San Rafael cactus Pediocactus despainii UT P Endangered

Santa Ana River 

woolly-star

Eriastrum densifolium ssp. 

sanctorum

CA P Endangered

Santa Ana sucker Catostomus santaanae CA V Threatened

Santa Barbara Island 

liveforever Dudleya traskiae CA P Endangered

Santa Catalina Island 

fox Urocyon littoralis catalinae CA V Endangered

Santa Clara Valley 

dudleya Dudleya setchellii CA P Endangered

Santa Cruz cypress Cupressus abramsiana CA P Endangered

Santa Cruz Island bushmallowMalacothamnus fasciculatus 

var. nesioticus CA P Endangered

Santa Cruz Island 

dudleya Dudleya nesiotica CA P Threatened

Santa Cruz Island fox Urocyon littoralis santacruzae CA V Endangered

Santa Cruz Island 

fringepod Thysanocarpus conchuliferus CA P Endangered

Santa Cruz Island 

malacothrix Malacothrix indecora CA P Endangered

Santa Cruz Island 

rockcress Sibara filifolia CA P Endangered

Santa Cruz long-toed 

salamander

Ambystoma macrodactylum 

croceum

CA V Endangered

Santa Cruz tarplant Holocarpha macradenia CA P Threatened

Santa Monica 

Mountains dudleyea Dudleya cymosa ssp. ovatifolia CA P Threatened

Santa Rosa Island fox Urocyon littoralis santarosae CA V Endangered

Santa Rosa Island 

manzanita Arctostaphylos confertiflora CA P Endangered
A-52

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Scaleshell mussel Leptodea leptodon AR, MO, NE, 

OK, SD I Endangered

Schaus swallowtail 

butterfly

Heraclides aristodemus 

ponceanus

FL I Endangered

Schweinitz's sunflower Helianthus schweinitzii NC, SC P Endangered

Scioto madtom Noturus trautmani OH V Endangered

Scotts Valley 

polygonum Polygonum hickmanii CA P Endangered

Scrub blazingstar Liatris ohlingerae FL P Endangered

Scrub buckwheat Eriogonum longifolium var. 

gnaphalifolium FL P Threatened

Scrub lupine Lupinus aridorum FL P Endangered

Scrub mint Dicerandra frutescens FL P Endangered

Scrub plum Prunus geniculata FL P Endangered

Seabeach amaranth Amaranthus pumilus DE, NC, NJ, 

NY, SC, VA P Threatened

Sebastopol 

meadowfoam Limnanthes vinculans CA P Endangered

Sei whale Balaenoptera borealis CA, MA V Endangered

Sensitive joint-vetch Aeschynomene virginica MD, NC, NJ, 

VA P Threatened

Sentry milk-vetch Astragalus cremnophylax var. 

cremnophylax AZ P Endangered

Shale barren rockcress Arabis serotina VA, WV P Endangered

Shasta crayfish Pacifastacus fortis CA I Endangered

Sheepnose mussel Plethobasus cyphyus

AL, IA, IL, IN, 

KY, MN, MO, 

MS, OH, PA, 

TN, VA, WI, 

WV

I Endangered

Shenandoah salamander Plethodon shenandoah VA V Endangered

Shiny pigtoe Fusconaia cor AL, TN, VA I Endangered

Shinyrayed 

pocketbook Lampsilis subangulata AL, FL, GA I Endangered

Shivwits milk-vetch Astragalus ampullarioides UT P Endangered
A-53

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Short-leaved rosemary Conradina brevifolia FL P Endangered

Shortnose sturgeon Acipenser brevirostrum

CT, DE, FL, 

GA, MA, MD, 

ME, NC, NJ, 

NY, PA, RI, SC, 

VA

V Endangered

Shortnose sucker Chasmistes brevirostris CA, OR V Endangered

Short's goldenrod Solidago shortii IN, KY P Endangered

Short-tailed albatross Phoebastria (=Diomedea) 

albatrus

CA, HI, OR, 

WA V Endangered

Showy Indian clover Trifolium amoenum CA P Endangered

Showy stickseed Hackelia venusta WA P Endangered

Shrubby reed-mustard Schoenocrambe suffrutescens UT P Endangered

Sierra Nevada bighorn 

sheep Ovis canadensis sierrae CA V Endangered

Siler pincushion 

cactus

Pediocactus 

(=Echinocactus,=Utahia) 

sileri

AZ, UT P Threatened

Sinaloan jaguarundi Herpailurus (=Felis) 

yagouaroundi tolteca NA1 V Endangered

Slackwater darter Etheostoma boschungi AL, TN V Threatened

Slender campeloma Campeloma decampi AL I Endangered

Slender chub Erimystax cahni TN, VA V Threatened

Slender-horned 

spineflower Dodecahema leptoceras CA P Endangered

Slender Orcutt grass Orcuttia tenuis CA P Threatened

Slender-petaled 

mustard Thelypodium stenopetalum CA P Endangered

Slender rush-pea Hoffmannseggia tenella TX P Endangered

Slickspot peppergrass Lepidium papilliferum ID P Threatened

Small-anthered 

bittercress Cardamine micranthera NC, VA P Endangered

Small Kauai 

(=puaiohi) thrush Myadestes palmeri HI V Endangered

Small's milkpea Galactia smallii FL P Endangered
A-54

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Smalltooth sawfish Pristis pectinata

AL, FL, GA, 

LA, MS, NC, 

SC, TX

V Endangered

Small whorled 

pogonia Isotria medeoloides

CT, DE, GA, IL, 

MA, ME, MI, 

MO, NC, NH, 

NJ, NY, OH, 

PA, RI, SC, TN, 

VA, WV

P Threatened

Smith's blue butterfly Euphilotes enoptes smithi CA I Endangered

Smoky madtom Noturus baileyi TN V Endangered

Smooth coneflower Echinacea laevigata GA, NC, SC, 

VA P Endangered

Snail darter Percina tanasi AL, GA, TN V Threatened

Snake River physa 

snail Physa natricina ID I Endangered

Snakeroot Eryngium cuneifolium FL P Endangered

Sneed pincushion 

cactus

Coryphantha sneedii var. 

sneedii NM, TX P Endangered

Snuffbox mussel Epioblasma triquetra

AL, AR, IL, IN, 

KY, MI, MN, 

MO, MS, OH, 

PA, TN, VA, 

WI, WV

I Endangered

Sockeye salmon Oncorhynchus (=Salmo) 

nerka OR, WA V Endangered

Sockeye salmon Oncorhynchus (=Salmo) 

nerka WA V Threatened

Socorro isopod Thermosphaeroma 

thermophilus NM I Endangered

Socorro springsnail Pyrgulopsis neomexicana NM I Endangered

Soft bird's-beak Cordylanthus mollis ssp. 

mollis CA P Endangered

Soft-leaved paintbrush Castilleja mollis CA P Endangered

Solano grass Tuctoria mucronata CA P Endangered
A-55

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Sonoma alopecurus Alopecurus aequalis var. 

sonomensis CA P Endangered

Sonoma spineflower Chorizanthe valida CA P Endangered

Sonoma sunshine Blennosperma bakeri CA P Endangered

Sonora chub Gila ditaenia AZ V Threatened

Sonoran pronghorn Antilocapra americana 

sonoriensis

AZ V Endangered

Sonora tiger 

Salamander Ambystoma tigrinum stebbinsi AZ V Endangered

Southeastern beach 

mouse

Peromyscus polionotus 

niveiventris FL V Threatened

Southern acornshell Epioblasma othcaloogensis AL, TN I Endangered

Southern clubshell Pleurobema decisum AL, GA, MS I Endangered

Southern combshell Epioblasma penita AL, MS I Endangered

Southern kidneyshell Ptychobranchus jonesi AL, FL I Proposed 

Endangered

Southern mountain 

wild-buckwheat

Eriogonum kennedyi var. 

austromontanum

CA P Threatened

Southern pigtoe Pleurobema georgianum AL, GA, TN I Endangered

Southern sandshell Hamiota (=Lampsilis) 

australis AL, FL I Proposed Endangered

Southern sea otter Enhydra lutris nereis CA V Threatened

South Texas ambrosia Ambrosia cheiranthifolia TX P Endangered

Southwestern willow 

flycatcher Empidonax traillii extimus

AZ, CA, CO, 

NM, NV, TX, 

UT

V Endangered

Spalding's catchfly Silene spaldingii ID, MT, OR, 

WA P Threatened

Speckled pocketbook Lampsilis streckeri AR I Endangered

Spectaclecase (mussel) Cumberlandia monodonta

AL, AR, IA, IL, 

KS, KY, MN, 

MO, TN, VA, 

WI, WV

I Endangered

Sperm whale Physeter catodon 

(=macrocephalus) CA, NC, PR V Endangered
A-56

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Spikedace Meda fulgida AZ, NM V Threatened

Spotfin Chub Erimonax monachus AL, NC, TN, 

VA V Threatened

Spotted Seal Phoca largha NA1 V Threatened

Spreading avens Geum radiatum NC, TN P Endangered

Spreading navarretia Navarretia fossalis CA P Threatened

Spring Creek 

bladderpod Lesquerella perforata TN P Endangered

Spring-loving centaury Centaurium namophilum CA, NV P Threatened

Springville clarkia Clarkia springvillensis CA P Threatened

Spruce-fir moss spider Microhexura montivaga NC, TN, VA I Endangered

Squirrel Chimney 

cave shrimp Palaemonetes cummingi FL I Threatened

Staghorn coral Acropora cervicornis FL, PR I Threatened

St. Andrew beach 

mouse

Peromyscus polionotus 

peninsularis FL V Endangered

Star cactus Astrophytum asterias TX P Endangered

Steamboat buckwheat Eriogonum ovalifolium var. 

williamsiae NV P Endangered

Stebbins' morningglory Calystegia stebbinsii CA P Endangered

Steelhead Oncorhynchus (=Salmo) 

mykiss CA V Endangered

Steelhead Oncorhynchus (=Salmo)

mykiss CA V Threatened

Steelhead Oncorhynchus (=Salmo) 

mykiss OR V Threatened

Steelhead Oncorhynchus (=Salmo) 

mykiss OR, WA V Threatened

Steelhead Oncorhynchus (=Salmo) 

mykiss WA V Threatened

Steller sea-lion Eumetopias jubatus CA, OR, WA V Threatened

Stephens' kangaroo rat Dipodomys stephensi (incl. D. 

cascus) CA V Endangered

Stirrupshell Quadrula stapes AL, MS I Endangered
A-57

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Stock Island tree snail Orthalicus reses (not incl. 

nesodryas) FL I Threatened

St. Thomas prickly-ash Zanthoxylum thomasianum PR P Endangered

Suisun thistle Cirsium hydrophilum var. 

hydrophilum CA P Endangered

Swamp pink Helonias bullata DE, GA, MD, 

NC, NJ, SC, VA P Threatened

Tan riffleshell Epioblasma florentina walkeri 

(=E. walkeri) KY, TN, VA I Endangered

Tapered pigtoe Fusconaia burkei AL, FL I Proposed 

reatened

Tar River spinymussel Elliptio steinstansana NC I Endangered

Telephus spurge Euphorbia telephioides FL P Threatened

Tennessee yelloweyed grass Xyris tennesseensis AL, GA, TN P Endangered

Terlingua Creek cat'seye Cryptantha crassipes TX P Endangered

Texas ayenia Ayenia limitaris TX P Endangered

Texas blind 

salamander Typhlomolge rathbuni TX V Endangered

Texas poppy-mallow Callirhoe scabriuscula TX P Endangered

Texas prairie dawnflower Hymenoxys texana TX P Endangered

Texas snowbells Styrax texanus TX P Endangered

Texas trailing phlox Phlox nivalis ssp. texensis TX P Endangered

Texas wild-rice Zizania texana TX P Endangered

Thread-leaved 

brodiaea Brodiaea filifolia CA P Threatened

Three Forks 

springsnail Pyrgulopsis trivialis AZ I Proposed Endangered

Tiburon jewelflower Streptanthus niger CA P Endangered

Tiburon mariposa lily Calochortus tiburonensis CA P Threatened

Tiburon paintbrush Castilleja affinis ssp. neglecta CA P Endangered

Tidewater goby Eucyclogobius newberryi CA V Endangered

Tiny polygala Polygala smallii FL P Endangered
A-58

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Tipton kangaroo rat Dipodomys nitratoides 

nitratoides CA V Endangered

Tobusch fishhook 

cactus

Ancistrocactus tobuschii TX P Endangered

Todsen's pennyroyal Hedeoma todsenii NM P Endangered

Tooth Cave ground 

beetle Rhadine persephone TX I Endangered

Tooth Cave 

pseudoscorpion Tartarocreagris texana TX I Endangered

Tooth Cave Spider Leptoneta myopica TX I Endangered

Topeka shiner Notropis topeka (=tristis) IA, KS, MN, 

MO, NE, SD V Endangered

Triangular kidneyshell Ptychobranchus greenii AL, GA, TN I Endangered

Triple-ribbed milkvetch Astragalus tricarinatus CA P Endangered

Tubercled blossom 

(pearlymussel) Epioblasma torulosa torulosa KY, TN, WV I Endangered

Tulotoma snail Tulotoma magnifica AL I Threatened

Tumbling Creek 

cavesnail Antrobia culveri MO I Endangered

Turgid blossom 

(pearlymussel) Epioblasma turgidula AL, AR, TN I Endangered

Uhiuhi Caesalpinia kavaiense HI P Endangered

Uinta Basin hookless 

cactus

Sclerocactus wetlandicus UT P Threatened

Umtanum Desert 

buckwheat Eriogonum codium WA P Proposed Threatened

Unarmored threespine 

stickleback

Gasterosteus aculeatus 

williamsoni CA V Endangered

Uncompahgre fritillary 

butterfly Boloria acrocnema CO I Endangered

[Unnamed] ground 

beetle Rhadine exilis TX I Endangered

[Unnamed] ground 

beetle Rhadine infernalis TX I Endangered
A-59

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

[Unnamed] pomace fly Drosophila aglaia HI I Endangered

[Unnamed] pomace fly Drosophila differens HI I Endangered

[Unnamed] pomace fly Drosophila hemipeza HI I Endangered

[Unnamed] pomace fly Drosophila heteroneura HI I Endangered

[Unnamed] pomace fly Drosophila montgomeryi HI I Endangered

[Unnamed] pomace fly Drosophila mulli HI I Threatened

[Unnamed] pomace fly Drosophila musaphila HI I Endangered

[Unnamed] pomace fly Drosophila neoclavisetae HI I Endangered

[Unnamed] pomace fly Drosophila obatai HI I Endangered

[Unnamed] pomace fly Drosophila ochrobasis HI I Endangered

[Unnamed] pomace fly Drosophila substenoptera HI I Endangered

[Unnamed] pomace fly Drosophila tarphytrichia HI I Endangered

Upland combshell Epioblasma metastriata AL, TN I Endangered

Utah prairie dog Cynomys parvidens UT V Threatened

Ute ladies'-tresses Spiranthes diluvialis

CO, ID, MT, 

NE, NV, UT, 

WA, WY

P Threatened

Uvillo Eugenia haematocarpa PR P Endangered

Vahl's boxwood Buxus vahlii PR P Endangered

Vail Lake ceanothus Ceanothus ophiochilus CA P Threatened

Valley elderberry 

longhorn beetle

Desmocerus californicus 

dimorphus CA I Threatened

Ventura marsh milkvetchAstragalus pycnostachyus var. 

lanosissimus CA P Endangered

Verity's dudleya Dudleya verityi CA P Threatened

Vermilion darter Etheostoma chermocki AL V Endangered

Vernal pool fairy 

shrimp Branchinecta lynchi CA, OR I Threatened

Vernal pool tadpole 

shrimp Lepidurus packardi CA I Endangered

Vine Hill clarkia Clarkia imbricata CA P Endangered

Virginia big-eared bat Corynorhinus (=Plecotus) 

townsendii virginianus

KY, NC, VA, 

WV V Endangered
A-60

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Virginia fringed 

mountain snail Polygyriscus virginianus VA I Endangered

Virginia northern 

flying squirrel Glaucomys sabrinus fuscus VA, WV V Endangered

Virginia round-leaf 

birch Betula uber VA P Threatened

Virginia sneezeweed Helenium virginicum MO, VA P Threatened

Virginia spiraea Spiraea virginiana

GA, KY, NC, 

OH, PA, TN, 

VA, WV

P Threatened

Virgin Islands tree boa Epicrates monensis granti PR V Endangered

Virgin River Chub Gila seminuda (=robusta) AZ, NV, UT V Endangered

Waccamaw silverside Menidia extensa NC V Threatened

Wahane Pritchardia aylmer-robinsonii HI P Endangered

Walker's manioc Manihot walkerae TX P Endangered

Warm Springs pupfish Cyprinodon nevadensis 

pectoralis NV V Endangered

Warner sucker Catostomus warnerensis NV, OR V Threatened

Watercress darter Etheostoma nuchale AL V Endangered

Water howellia Howellia aquatilis CA, ID, MT, 

OR, WA P Threatened

Wawae`iole Huperzia mannii HI P Endangered

Wawae`iole Lycopodium (=Phlegmariurus) 

nutans

HI P Endangered

Welsh's milkweed Asclepias welshii AZ, UT P Threatened

Wenatchee Mountains 

checkermallow Sidalcea oregana var. calva WA P Endangered

Western lily Lilium occidentale CA, OR P Endangered

Western prairie fringed 

orchid Platanthera praeclara

IA, KS, MN, 

MO, ND, NE, 

OK, SD

P Threatened

Western snowy plover Charadrius alexandrinus 

nivosus CA, OR, WA V Threatened
A-61

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

West Indian manatee Trichechus manatus

AL, FL, GA, 

LA, MS, NC, 

PR, SC, TX

V Endangered

West Indian walnut 

(=Nogal) Juglans jamaicensis PR P Endangered

Wheeler's peperomia Peperomia wheeleri PR P Endangered

White Abalone Haliotis sorenseni CA I Endangered

White birds-in-a-nest Macbridea alba FL P Threatened

White bladderpod Lesquerella pallida TX P Endangered

White Bluffs 

bladderpod

Physaria douglasii 

tuplashensis WA P Proposed Threatened

White catspaw 

(pearlymussel)

Epioblasma obliquata 

perobliqua IN, OH I Endangered

White-haired

goldenrod Solidago albopilosa KY P Threatened

White irisette Sisyrinchium dichotomum NC, SC P Endangered

White-necked crow Corvus leucognaphalus NA1 V Endangered

White-rayed 

pentachaeta Pentachaeta bellidiflora CA P Endangered

White River spinedace Lepidomeda albivallis NV V Endangered

White River springfish Crenichthys baileyi baileyi NV V Endangered

White sedge Carex albida CA P Endangered

White sturgeon Acipenser transmontanus ID, MT V Endangered

White wartyback 

(pearlymussel) Plethobasus cicatricosus AL, IN, KY, TN I Endangered

Whooping crane Grus americana

CO, KS, MT, 

ND, NE, OK, 

SD, TX

V Endangered

Wide-leaf warea Warea amplexifolia FL P Endangered

Willamette daisy Erigeron decumbens var. 

decumbens OR P Endangered

Willowy monardella Monardella viminea CA P Endangered

Winged mapleleaf Quadrula fragosa AR, MN, MO, 

OK, WI I Endangered

Winkler cactus Pediocactus winkleri UT P Threatened
A-62

Federally Threatened, Endangered, and Proposed Species in Corn Production U.S. States and Puerto 

Rico (continued)

Common Name Scientific Name Current

Distribution

Vertebrate (V)

Invertebrate (I)

Plant (P)

Listing Status

Wireweed Polygonella basiramia FL P Endangered

Woodland caribou Rangifer tarandus caribou ID, WA V Endangered

Wood stork Mycteria americana

AL, FL, GA, 

MS, NC, SC V Endangered

Woundfin Plagopterus argentissimus AZ, NM, NV, 

UT V Endangered

Wright fishhook cactus Sclerocactus wrightiae UT P Endangered

Wyoming toad Bufo baxteri (=hemiophrys) WY V Endangered

Yadon's piperia Piperia yadonii CA P Endangered

Yaqui catfish Ictalurus pricei AZ V Threatened

Yaqui chub Gila purpurea AZ V Endangered

Yellow blossom 

(pearlymussel)

Epioblasma florentina 

florentina AL, TN I Endangered

Yellow-blotched map 

turtle Graptemys flavimaculata MS V Threatened

Yellowcheek darter Etheostoma moorei AR V Endangered

Yelloweye rockfish Sebastes ruberrimus NA1 V Threatened

Yellowfin madtom Noturus flavipinnis TN, VA V Threatened

Yellow larkspur Delphinium luteum CA P Endangered

Yellow-shouldered 

blackbird Agelaius xanthomus PR V Endangered

Yreka phlox Phlox hirsuta CA P Endangered

Yuma clapper rail Rallus longirostris yumanensis AZ, CA, NV V Endangered

Zapata bladderpod Lesquerella thamnophila TX P Endangered

Zayante band-winged 

grasshopper Trimerotropis infantilis CA I Endangered

Zuni fleabane Erigeron rhizomatus AZ, NM P Threatened

Note 1. Specific current distribution is not available, but these species are listed wherever found.

Reference:

USFWS. (2012). Species Reports, Environmental Conservation Online System. Retrieved May 

17, 2012, from U.S. Fish and Wildlife Service, http://ecos.fws.gov/tess_public/.