i

Pesticide Use in the 

Imported Fire Ant Program

Environmental Assessment

March 2012

United States

Department of 

Agriculture

Marketing and 

Regulatory 

Programs

Animal and 

Plant Health 

Inspection 

Service
ii

Pesticide Use in the Imported 

Fire Ant Program

Environmental Assessment

March 2012

Agency Contact:

Charles Brown

Director, Emergency Management

Emergency and Domestic Programs

Animal and Plant Health Inspection Service

U.S. Department of Agriculture

4700 River Rd. Unit 134

Riverdale, MD 20737

_____________________________________________________

The U.S. Department of Agriculture (USDA) prohibits discrimination in all its 

programs and activities on the basis of race, color, national origin, sex, 

religion, age, disability, political beliefs, sexual orientation, or marital or family 

status. (Not all prohibited bases apply to all programs.) Persons with 

disabilities who require alternative means for communication of program 

information (Braille, large print, audiotape, etc.) should contact USDA’S 

TARGET Center at (202) 720–2600 (voice and TDD).

To file a complaint of discrimination, write USDA, Director, Office of Civil Rights, 

Room 326–W, Whitten Building, 1400 Independence Avenue, SW, Washington, 

DC 20250–9410 or call (202) 720–5964 (voice and TDD). USDA is an equal 

opportunity provider and employer.

_____________________________________________________

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. 

_____________________________________________________

CAUTION: Pesticides can be injurious to humans, domestic animals, 

desirable plants, and fish or other wildlife—if they are not handled or applied 

properly. Use all pesticides selectively and carefully. Follow recommended 

practices for the disposal of surplus pesticides and pesticide containers.
iii

Table of Contents

I. Introduction ....................................................................................... 1

A. Distribution and Biology of IFA................................................. 1

B. APHIS Fire Ant Quarantine Program ....................................... 3

C. Purpose and Need for IFA Quarantine Program Changes..... 5

D. Scope of Analysis...................................................................... 7

II. Alternatives ...................................................................................... 8

A. No Action................................................................................... 8

B. Preferred Alternative................................................................. 9

III. Affected Environment...................................................................12

A. Land Use and Ecological Resources within the Geographic 

Area...............................................................................................12

B. Air Quality within the Geographic Area..................................14

C. Water Quality within the Geographic Area ............................14

IV. Environmental Effects..................................................................15

A. No Action.................................................................................16

B. Preferred Alternative...............................................................28

V. Cumulative Impacts ......................................................................41

VI. Other Environmental Considerations..........................................44

A. Executive Orders ....................................................................44

B. Threatened and Endangered Species ...................................45

VII. Listing of Agencies and Persons Consulted...............................46

VIII. Appendices.................................................................................47

Appendix I. Observed Damage to Wildlife by IFA .....................47

Appendix II. Land Resource Regions Overlapping with the 

Geographic Areas Covered in this Environmental Assessment 48

Appendix III. Major Uses of Land (2007) for States within the 

IFA Quarantine and the Expanded Geographic Area Covered in 

this Environmental Assessment...................................................50

Appendix IV. Counties within the IFA Quarantine and the 

Expanded Geographic Area Covered in this Environmental 
iv

Assessment that are Designated as Nonattainment Areas for 

One or More Common Air Pollutants Tracked by the 

Environmental Protection Agency (EPA) ....................................51

Appendix V. Number of Watersheds and Watersheds 

Containing Waters Impaired with Chemicals Used in the IFA 

Program ........................................................................................53

IX. References ...................................................................................55
1

I. Introduction

The invasive insects, Solenopsis invicta Buren (S. invicta Buren), and S. 

richteri Forel (S. richteri Forel) and their hybrids, collectively known as

imported fire ant1 (IFA) (Hymenoptera: Formicidae) are a health hazard to 

humans, domestic animals, and wildlife; a nuisance in public and 

agricultural lands; and can cause infrastructure damage. IFA has become

established throughout the southern United States, as well as Puerto Rico. 

In response to the introduction of IFA to the United States, the Federal 

government implemented a quarantine in 1958, with periodic revisions, to 

update expansion of IFA, as well as identify new control measures. An 

update to the approved list of pesticides for use in commercial plant 

nurseries and grass sod farms (under the Federal IFA quarantine program),

as well as an evaluation of the expansion of the quarantine area to 

determine whether control of IFA is needed in new areas, are needed to 

prevent further movement of IFA.

A. Distribution and Biology of IFA

Two species of IFA were introduced into the United States from South 

America at the port of Mobile, Alabama. The black imported fire ant, 

S. richteri Forel, arrived sometime around 1918 and the red imported fire 

ant, S. invicta Buren, in the late 1930s. Both species probably came to the 

port in soil used as ballast in cargo ships. 

Solenopsis invicta is known to infest portions or all of Alabama, Arkansas, 

California, Florida, Georgia, Louisiana, Mississippi, New Mexico, North 

Carolina, Oklahoma, South Carolina, Tennessee, Texas, Virginia, and 

Puerto Rico. In the United States, S. richteri is only reported from 

northeastern Mississippi, northwestern Alabama, and southern Tennessee. 

A hybrid of S. invicta and S. richteri has been found from the middle of 

both Mississippi and Alabama northward, in the southeastern corner of 

Tennessee, and the northwestern corner of Georgia (Diffie et al. 1988).

IFA disperses naturally through mating flights, colony movement (ants 

can relocate their colony), and sometimes through rafting2

 1 The common name for Solenopsis invicta is red imported fire ant; for S. richteri, black imported fire 

ant. Synonyms for imported fire ant include red imported fire ant, fire ant, RIFA and IFA.

during periodic 

floods. Naturalspread occurs slowly and within a local area. However, 

the rapid spread of IFA throughout the southern portion of the United 

States since the 1950s was likely due to human activities—fire ants can be 

transported in dirt clods attached to vehicles and machinery; can be moved 

in soil-containing products, including nursery stock and commercial sod; 

and can be associated with baled hay and woody ornamental plants used in 

2 Rafting is the process by which IFA form a mass of intertwined ants and float on water during heavy 

rains or floods (http://www.insectscience.org/11.171/i1536-2442-11-171.pdf)
2

landscaping. Soil used in construction projects, such as road construction, 

is also a likely avenue through which fire ants spread (King et al. 2009). 

The infestations in almond groves in Kern County, California likely 

originated from bee hives transported from infested States for the purpose 

of pollinating crops (Wojcik et al. 2001). 

Similar to other ant species, IFA form colonies in which ants have specific 

roles (also called a socially hierarchical colony). A typical S. invicta

colony (nest) has one or more queens. Within the colony there are two 

types of ant groups: worker groups (classified as minims, minors, and 

majors based on size) comprised of sterile females and sexual groups

(Lofgren et al. 1975). The percentage of the colony comprised of these 

two castes varies depending on the time of year and the age of the colony; 

sexuals are produced primarily in the spring. The female controls the sex 

of her offspring by fertilizing or not fertilizing an egg (Tschinkel 2006). 

Males arise from unfertilized eggs while females arise from fertilized eggs 

(Tschinkel 2006). The number of winged sexuals participating in a nuptial 

flight (males and females mate in the air) is around 600 to 700 per flight of 

which around 95 percent of the females will have mated (Tschinkel 2006). 

A mature colony, on average, participates in around eight to nine flights 

per year; not all sexuals are released for every flight. 

After their nuptial flight, new queens start forming and usually complete 

their nest within 6 to 7 hours after mating (Lofgren et al. 1975). The first 

eggs are laid within 24 to 48 hours after completing their nest. The time 

from egg to first adult worker is between 18 to 30 days—the first larvae 

hatch in about a week and both the larval (4 instars total) and pupal stages

last about a week (Lofgren et al. 1975, Tschinkel 2006). Queens may live 

for 6 or 7 years and can produce as many as 1,500 eggs per day using 

stored sperm from their one-time mating. Males live for approximately 

4 days. Workers (sterile females) live between 1 and 6 months (Tschinkel 

2006). Within 3 years (considered the colony’s maturation point), the 

colony’s population can reach 230,000 workers (which the authors 

consider to be a conservative estimate) (Lofgren et al. 1975). The colony 

size does fluctuate throughout the year, being at its highest population 

levels in late fall and at its lowest population levels in spring (Tschinkel 

2006). Colonies die of old age in 5 to 8 years and are replaced by younger 

colonies (Tschinkel 2006).

Temperature and soil moisture, as well as the physical properties of the 

soil are important for colony foundation and survival (Lofgren et al. 

1975). Fire ants are unable to effectively forage when soil temperatures at 

a 2-centimeter (cm) depth are below 15 °C; they are unable to produce a 

brood (eggs, larvae, and pupae) when soil temperatures are below 24 °C 

(Tschinkel 2006). In central and south Florida, brood production can 

occur year round; at its most northern range, brood production ceases in 
3

the wintertime. On average, the seasonal reproductive cycle begins in 

March and ends in October.

A mature mound can extend 1 meter or more into the ground, reaching the 

water table in some areas. The size of the mound above ground varies 

depending on the soil type. There is evidence that large colonies can 

occupy several mounds. A mature mound may remain viable for several 

years (Lofgren et al. 1975). The density of colonies in the United States 

averages around 500 mounds/hectare (ha); densities of 1,400 mounds/ha 

have been recorded (cited in (Allen et al. 2004)). 

Fire ants are generalist feeders, feeding on plants and domestic and wild 

animals. Preferred food sources include insects, spiders, myriapods 

(subphylum of arthropods containing millipedes, centipedes, and others), 

earthworms, and other small invertebrates (Lofgren et al. 1975).

States in which IFAs are present and likely to expand into additional noninfested counties include Arizona, California, New Mexico, North 

Carolina, and Texas, as well as a northern expansion in Arkansas,

Oklahoma, and Tennessee (Korzukhin et al. 2001). IFA could potentially 

spread to and annually survive in portions of Delaware, Hawaii, Maryland, 

Nevada, Oregon, Utah, Virginia and Washington (Korzukhin et al. 2001).

In more arid climates, IFA would likely be restricted to areas along water 

courses and irrigated lands (Korzukhin et al. 2001). A map of IFA 

distribution and expansion in the United States, based on Korzukhin et al.,

(2001) is available on the U.S. Department of Agricultural Research 

Service (ARS) website:

http://www.ars.usda.gov/Research/docs.htm?docid=9165. Overlaying 

climate change scenarios on predictive spread models indicate that the 

range of IFA survival in Oklahoma will likely move northward (and 

westward) given the increase in air temperatures and wetter climate (Levia 

and Frost 2004).

B. APHIS Fire Ant Quarantine Program

USDA–APHIS currently conducts regulatory actions to quarantine IFA 

under the Plant Protection Act (7 U.S. Code (U.S.C.) 7701, et seq.), and 

the implementing regulations are currently contained in 7 Code of Federal 

Regulations (CFR) 301 Subpart Imported Fire Ant (301.81–1–301.81–10). 

The purpose of the Federal quarantine (7 CFR § 301.81) is to prevent the 

artificial spread of IFA into noninfested areas of the United States by 

regulating the following articles:

• IFA queens and reproducing colonies of IFA

• Soil, separate or with other articles

o For example, containerized plants
4

• Baled hay or straw stored in direct contact with the ground

• Plants and sod with roots and soil attached, except plants 

maintained indoors in a home or office environment and not for 

sale

o For example, balled and burlapped plants, field sod, field 

grown commodities

• Used soil-moving equipment, unless removed of all noncompacted 

soil

The Federal IFA quarantine “does not require control or eradication 

programs” (USDA APHIS PPQ 2010). However, before regulated articles 

are moved from a quarantine area to a nonquarantine area they must be

free of infestation and must be treated according to approved procedures 

(USDA APHIS 2007), or must be grown or produced in a manner that 

would ensure freedom from infestation (USDA APHIS PPQ 2010). 

Regulated articles meeting these requirements must be accompanied with 

a certificate for interstate movement (USDA APHIS PPQ 2010). 

Facilities shipping regulated articles must be done either under a 

compliance agreement or a limited permit (USDA APHIS PPQ 2010).

According to 7 § CFR 301.81 (revised January 1, 2011) and Memo DA2009–54 (October 28, 2009, 

http://www.aphis.usda.gov/plant_health/plant_pest_info/fireants/download

s/da-2009-54.pdf), the following areas are under Federal quarantine

(figure 1):

• Entire State: Alabama, Florida, Georgia, Louisiana, Mississippi,

and South Carolina

• Part of the State: Arkansas, California (one county and part of two 

others), New Mexico (one county), North Carolina, Oklahoma, 

Tennessee, Texas, and Virginia

• Territories: Puerto Rico (entire)

The current IFA program involves surveys and quarantine requirements on 

potentially infested commodities. The quarantine requirements involve 

the use of chemical treatments on commodities to insure that shipments 

from nurseries, sod farms, and field-growing nursery facilities are free of 

IFA. 
5

Figure 1. Imported fire ant (IFA) quarantine in the United States as of 

December, 2011.

C. Purpose and Need for IFA Quarantine Program 

Changes

APHIS is responsible for taking actions to exclude, eradicate, and/or 

control plant pests under the Plant Protection Act (7 U.S.C. 7701 et seq.). 

As such, it is important that APHIS take the steps necessary to prevent the 

artificial spread of IFA from the current infested counties to new areas.

APHIS proposes to change its IFA Federal quarantine program regulations 

by revising the list of approved pesticides and the commodity type (plants 

grown in containers, balled and burlapped, or field or grass sod) to which 

they are applied for use against IFA in commercial nursery and sod 

facilities, and to expand the areas in which quarantine activities may be 

conducted. 

APHIS has determined that under the provisions of the National 

Environmental Policy Act (NEPA) (see 42 U.S.C. 4321 et seq.) and 

APHIS’ National Environmental Policy Act (NEPA) implementing 

procedures (see 7 CFR part 372), an environmental assessment (EA)

should be prepared for these proposed actions. The availability of this EA 

and a 30-day comment period will be announced by publishing a notice in 

the Federal Register. APHIS’ decisionmaker for the actions described in 

this EA will take appropriate action after reviewing the EA, its associated 

analyses, public comments received, and other relevant responses and 
6

recommendations. If major changes to the proposed actions in this EA 

occur as a result of this process, or if APHIS’ decision is a finding of no 

significant impact (FONSI), APHIS will prepare a similar announcement 

to notify the public of the decision being made. APHIS has prepared two 

other EAs that are relevant to this EA: Imported Fire Ant Regulatory 

Program, January 1999, and Imported Fire Ant Regulatory Program, 

February 1992.

APHIS needs to change the approved list of pesticides because options for 

chemical control of IFA through the use of insecticides have evolved over 

time. Changes in availability of insecticides that are effective against IFA,

as well as ensuring a range of pest management options requires APHIS to 

periodically evaluate new treatment options. In addition, the U.S. 

Environmental Protection Agency (EPA) regulates the registration, 

distribution, sale, and use of pesticides under its Federal Insecticide, 

Fungicide and Rodenticide Act (FIFRA; 7 U.S.C. §136 et seq. (1996))

regulations. As pesticide registrations change, the chemicals available for 

use to control IFA also change. USDA–APHIS needs to evaluate the 

current pesticide options for IFA control and determine their applicability,

and human health and environmental impacts resulting from use in the 

Federal quarantine program.

In addition, IFA continues to pose a threat to human health, domestic 

animals, wildlife, public and agricultural lands, and property so there is a 

need to ensure effective control methods are available.

From a human health perspective, an estimated 14 million people are 

stung annually (Drees 2002). “Approximately 30% of the people living in 

infested areas are stung each year; of these, approximately 1% may 

develop hypersensitivity to the ant’s venom” (Vinson, 1997 cited in

(Wojcik et al. 2001)). In 1998, approximately 33,000 people sought 

medical treatment for IFA bites in South Carolina at an estimated cost of 

$2.4 million (Caldwell et al. 2009).

Adverse economic impacts caused by IFA are mostly attributed to control 

programs rather than from direct impact from IFA. Sources of economic 

impact include the cost of treatment on agricultural lands to protect 

livestock and farm workers, and on public lands to protect people and 

wildlife; cost of treatment on residential property; cost to regulatory 

agencies; infrastructure damage to highways, telephone and cable lines; 

cost of medical treatment for both humans and animals; reduction in 

economic profit to industries restricted from shipping materials that are 

under quarantine; and funding costs for research. Annual cost of 

$1.3 billion and $1.2 billion are estimated for the States of Florida and 

Texas, respectively (Lard et al. 2006). Establishment of IFA in California 

could cost the State between $387 million and $989 million per year 

(Jetter et al. 2002); in Hawaii, $211 million per year (Gutrich et al. 2007). 
7

Lard et al. (2006) estimates IFA costs the United States, including Puerto 

Rico, ca. $6 billion annually. The range of fire ants is expected to expand 

and with it the economic impacts will likely increase as control programs 

are implemented in new areas.

Numerous papers on the mortality to vertebrates and invertebrates caused 

directly or indirectly by IFA are published in scientific literature. In 

addition, IFA is harmful to species designated as threatened or endangered 

at the Federal level, State level, or both (appendix 1 lists a few examples). 

IFA is considered a culprit in the extinction in the wild of the Stock Island 

tree snail (Orthalicus reses reses (Say)) (Wojcik et al. 2001). Diffie et al. 

(2010) estimate that over 246 reptilian species reside in areas in which fire 

ants inhabit, all of which can be impacted by IFA. Research is underway 

to determine the impact of IFA on the Schaus swallowtail, Papilio 

aristodemus onceanus Schaus, a federally listed endangered species whose 

population has been in decline (Wojcik et al. 2001).

IFA can negatively impact native arthropod communities through 

predation and competition, resulting in loss of ecological communities 

(including loss of species diversity and trophic simplification) (Allen et al. 

2001, Epperson and Allen 2010). Arthropods are an integral part of 

ecosystem functions, including nutrient cycling, seed dispersal, 

decomposition, and pollination (cited in (Epperson and Allen 2010)). 

Native ant species diversity and richness are greater in areas treated for 

IFA, indicating that arthropod communities are negatively impacted by 

IFA (Allen et al. 2001, Epperson and Allen 2010).

D. Scope of Analysis

This EA will analyze the human health and environmental impacts that 

can be reasonably expected to occur if the proposed action to update the 

Federal quarantine activities for IFA is implemented. These activities will 

only take place in commercial plant nurseries that produce containergrown, balled and burlapped, field grown plants and/or sod within the IFA 

quarantine and wish to ship to areas outside of the quarantine.

Current IFA infestations and associated quarantine areas are documented 

in all or part of Alabama, Arkansas, California, Florida, Georgia, 

Louisiana, Mississippi, New Mexico, North Carolina, Oklahoma, South 

Carolina, Tennessee, Texas, Virginia, and Puerto Rico. The areas 

requiring quarantine activities are likely to expand due to the effects of 

climate change. Maps depicting the potential expansion of the pest are 

available on the USDA Agricultural Research Service (ARS) Website at 

www.ars.usda.gov/Research/docs.htm?docid=9165. 

This EA will analyze quarantine activities in the current quarantine area

(figure 1), as well as activities that may be carried out in expanded 
8

quarantine areas as the detection of IFA in new areas could occur. The 

geographical region covered in this EA includes the current IFA 

quarantine area, as well as the remainder of the counties in the States of 

Arkansas, North Carolina, Oklahoma, Tennessee, Texas, and Virginia. In 

California, five additional counties are included in the scope (San 

Bernardino, Ventura, Santa Barbara, San Diego, and Imperial) and the 

counties of Los Angeles and Riverside are included entirely. Published 

data on the potential expansion of IFA demonstrate a much larger area for 

expansion than what is covered in the scope of this EA. The selection and 

addition of counties to the scope of analysis in this EA was based on a 

combination of factors, such as the current areas of IFA infestation, where 

recent expansion of IFA has been observed, and the published literature

regarding potential areas of expansion. 

II. Alternatives

This EA will analyze the potential environmental and human health effects

anticipated from two alternatives in response to the need—(1) no action,

and (2) the preferred alternative, changing certain IFA pesticides and use 

patterns. 

A. No Action

Under the no action alternative, the chemicals which are currently 

authorized by APHIS for the treatment of sod, field grown plants,

container grown plants, and balled and burlapped plants under the IFA 

quarantine (table 1–1) would continue to be used within the area under 

quarantine as long as they are registered for use by EPA. Two active 

ingredients, diazinon and tefluthrin, that have been part of the IFA 

quarantine program are no longer registered for IFA use and therefore will 

not be analyzed in this EA. 
9

Table 1–1. Current Insecticides Used for IFA Quarantine.

Active 

Ingredient

Formulation

Name

Formulation

Type+

Commodity

Container FieldgrownB&B1 Grass 

sod

Bifenthrin

Talstar®, 

Bifenthrin Pro®, 

Onyx Pro® G, F, EC X

Chlorpyrifos Dursban®

, 

Chlorpyrifos EC, WP, G X X X X

Diazinon2 Diazinon/D-z-n

® WP, EC X

Fenoxycarb Aw ard® Bait X

Fipronil

Chipco® ChoiceTM,

Chipco®,

Top ChoiceTM G X X3 X

Hydramethylnon Amdro®Pro,

Siege® Pro Bait X

Methoprene Extinguish® Bait X

Pyriproxyfen Distance® Bait X

Tefluthrin2 Fireban® G X

1

B&B = Balled and burlapped plants 2 No longer available for IFA quarantine use.

3 Approved by 24C in the State of Tennessee for field grown use

+ WP = wettable powder; EC = emulsifiable concentrate; G = granular; and F = flowable

B. Preferred Alternative

Under the preferred alternative, APHIS is proposing to add additional

insecticides and use patterns to the list of chemicals already allowed in the 

IFA program and listed in the no action alternative (table 1–2). In 

addition, APHIS is removing the use of diazinon and tefluthrin from the 

list of treatments for use in the IFA program because these are no longer 

registered for use. The additional insecticides are being added to provide 

a broader range of chemical treatment options and are not being proposed 

as additional treatments beyond what is currently required in the 

quarantine program. All of the products have residential and/or 

commercial uses in nurseries to control other pests.
10

Table 1–2. Preferred Insecticides and Use Patterns for IFA Quarantine.

Active 

Ingredient

Formulation

Name

Formulation

Type+

Commodity

Container FieldgrownB&B3 Grass 

sod

Bifenthrin

Talstar®, 

Bifenthrin Pro®, 

Onyx Pro®

G, F, EC X X X X

Chlorpyrifos Dursban®

, 

Chlorpyrifos EC, WP,G X X X X

Fenoxycarb Aw ard® Bait X

Fipronil

Chipco®ChoiceTM,

Chipco® Top,

ChoiceTM G X X1 X

Hydramethylnon Amdro®Pro, 

Siege®Pro Bait X

Methoprene Extinguish® Bait X

Pyriproxyfen Distance® Bait X

Bifenthrin +

Cypermethrin Talstar® Xtra G X X X

Bifenthrin + 

Clothianidin Aloft® SC X X

Bifenthrin + 

Imidacloprid Allectus® G, SC X

Permethrin2 GardStar® EC

Imidacloprid + 

Cyfluthrin DiscusTM G X X X

λ-cyhalothrin Scimitar® G, SC X X X X

1 Approved by 24C in state of Tennessee for field grown use 2 Use on/around hay and bees as a soil drench treatment for ants

3 B&B = Balled and burlapped plants + WP = wettable powder, EC = emulsifiable concentrate, G = granular, F = flowable, 

SC = suspension concentrate

In summary, the changes that would result if the preferred alternative is 

implemented are as follows: 

• For bifenthrin, the same three formulations (Talstar®, Bifenthrin Pro®, 

and Onyx Pro®) and the same formulation types (granular, flowable,

and emulsifiable concentrate) would be used on container-grown 

plants, field-grown plants, balled and burlapped plants, and grass sod

instead of container-grown plants only (four commodity types);

• For chlorpyrifos, the same two formulations (Dursban® and 

chrlorpyrifos) and the same formulation types (emulsifiable 

concentrate, wettable powder, and granular) would be used on all four 
11

commodity types, resulting in no change in the way this pesticide is 

used in the IFA program;

• For diazinon, the option for use of any formulation would be removed 

from the IFA program because it is no longer registered for this use;

• For fenoxycarb, the same bait formulation of Award® would used on 

field-grown plants, resulting in no change in the way this pesticide is 

used in the IFA program;

• For fipronil, the same two granular formulations of Chipco® ChoiceTM 

and Chipco® Top ChoiceTM would be used on container-grown plants, 

field-grown plants, and grass sod, resulting in no change in the way 

this pesticide is used in the IFA program;

• For hydramethylnon, the same two bait formulations of Amdro® Pro 

and Siege® Pro would be used on field-grown plants, resulting in no 

change in the way this pesticide is used in the IFA program;

• For methoprene, the same bait formulation of Extinguish®

would be 

used on field-grown plants, resulting in no change in the way this 

pesticide is used in the IFA program;

• For pyriproxyfen, the same bait formulation of Distance® would be 

used on field-grown plants, resulting in no change in the way this 

pesticide is used in the IFA program;

• For the pesticide combination of bifenthrin and cypermethrin, a

granular formulation of Talstar® Xtra, for use on container-grown 

plants, field-grown plants, and grass sod would be added to the options 

available for IFA control;

• For the pesticide combination of bifenthrin and clothianidin, one 

suspension concentrate formulation of Aloft® for use on field-grown 

plants and grass sod would be added to the options available for IFA 

control;

• For the pesticide combination of bifenthrin and imidacloprid, granular 

and suspension concentrate formulations of Allectus® for use on balled 

and burlapped plants would be added to the options available for IFA 

control;

• For permethrin, one emulsifiable concentrate formulation of GardStar®

for use on and around hay as a soil drench treatment for ants would be 

added to the options available for IFA control;
12

• For the pesticide combination of imidacloprid and cyfluthrin, one 

granular formulation of DiscusTM for use on field-grown plants, balled 

and burlapped plants, and grass sod would be added to the options 

available for IFA control;

• For the pesticide tefluthrin, the option for use of any formulation 

would be removed from the IFA program because it is no longer 

registered for this use; and 

• For the pesticide λ-cyhalothrin, granular and suspension concentrate 

formulations of Scimitar® for use on container-grown plants, fieldgrown plants, balled and burlapped plants, and grass sod would be 

added to the options available for IFA control.

III. Affected Environment

The area under the Federal IFA quarantine is broad (impacting 14 States 

and one territory) and has a diversity of soil types, animals (vertebrates

and invertebrates), plants, and climatic factors. Although the quarantine 

area is broad, IFA program activities, namely the application of pesticides 

at facilities that commercially produce or sell regulated articles for 

distribution outside of the quarantine area, will not impact the entire 

quarantine area; only those areas under or near treatment. 

The nursery and grass sod industry in the United States, including those 

located in the region covered in this EA, implement pest management in 

their facilities, and the use of pesticides may be one of the management 

options utilized. In conventional growing practices for nursery plants and 

grass sod, pesticides, including those belonging to the amidinohydrazone, 

carbamate, insect growth regulator, neonicotinoid, organophospate, 

phenylpyrazol, and pyrethroid pesticide classes may be used to control a 

range of insect pests, not just IFA. Pesticide formulations belonging to 

these classes are also used in conventional agricultural crop production to 

control insect pests; used in animal production to control nuisance pests to 

livestock; and for residential use to control garden or infrastructure pests,

or even pests on pets. 

The discussion below provides an overview of the affected environment, 

including ecological resources and air and water quality for areas under 

the current IFA quarantine, and the expanded areas described in this EA.

A. Land Use and Ecological Resources within the 

Geographic Area

There are 11 land resource regions that overlap with the geographic areas 

covered in this EA (appendix 2). Land resource regions are 
13

“geographically associated major land resource areas which approximate 

broad agricultural market regions” (USDA NRCS 2006). For a detailed 

description of the land resource regions, please see the Land Resource 

Regions and Major Land Resource Areas of the United States, the 

Caribbean, and the Pacific Basin available on the U.S. Natural Resources 

Conservation Service Website (ftp://ftpfc.sc.egov.usda.gov/NSSC/Ag_Handbook_296/Handbook_296_high.pdf).

Every 5 years, the USDA–Economic Research Service compiles a report 

on the major uses of land in the United States; the latest report available is 

based on data from 2007. Approximately 48 percent of land use in the 

region covered in this assessment is for cropland and grassland, which 

includes pasture and range. This is a slight overestimate because only 

eight counties in California and one county in New Mexico are included in 

the geographic scope; removing these States from land use calculations 

brings the estimated total to 46 percent. Appendix 3 provides a summary 

of land use in the States covered in the scope of this assessment.

National, State, county, and city parks, as well as National Wildlife 

Refuges are located within the geographic area described for this 

assessment. The estimates of acres dedicated to special-use areas 

available in appendix 3 include these lands. Parks are considered mixeduse and are used for recreational purposes, as well preservation of animal 

habitats and ecological resources. National Wildlife Refuges are managed 

by the U.S. Fish and Wildlife Service and are areas set aside to conserve 

fish, wildlife, and plants. A wide diversity of terrestrial and aquatic 

habitats occurs within the geographic boundary considered in this EA. 

These habitats support a wide diversity of fish and wildlife species, with 

many rare and endangered species. Approximately 606 species listed as 

threatened or endangered under the Endangered Species Act occur within 

the boundary defined in this EA. Natural habitats may have IFA 

infestations; however, the quarantine program is directed solely at 

treatments within commercial nurseries. These are highly disturbed areas 

that may have some use by wildlife, but would not be preferred habitats to 

support wildlife populations. Similar to soils in agricultural production, 

nurseries and sod farms are disturbed creating preferred habitat for IFA 

(Tschinkel 2006). 

There are approximately 9 dominant soil orders (of a total of 12 orders) 

and 44 dominant soil suborders (of a total of 64 suborders) in the land 

resource regions that are encompassed within the geographic area of this 

EA (appendix 2). Soil orders “are differentiated by the presence or 

absence of diagnostic horizons or features that reflect soil forming 

processes.” (USDA NRCS 1999). The criteria for differentiating 

suborders vary between soil orders. For example, a suborder under one 

soil order is differentiated based on its wetness, while a suborder under 

another soil order is differentiated based on its dominant temperature 
14

regime. The physical properties of soil influence water holding capacity 

and runoff, as well as the binding affinity of various pesticides. Both the 

physical properties of soil as well as soil moisture are important for IFA 

colony formation and survival (Lofgren et al. 1975). Disturbed soils that 

would support IFA colony formation will have different physical 

characteristics compared to any surrounding undisturbed soils. Soils 

become disturbed through various agricultural practices, including 

planting, harvesting, tilling, and application of organic and inorganic 

amendments.

 

B. Air Quality within the Geographic Area

There are 86 counties in the current quarantine area and expanded area 

described for this EA that are designated as nonattainment areas, meaning 

the air pollution levels persistently exceed the national ambient air quality 

standards set by EPA (appendix 4). Counties may reach nonattainment for 

more than one air pollutant, as is the case for several counties in the IFA 

quarantine area. Forty-nine counties are designated as nonattainment 

areas due to their particulate matter levels (combining county listings for 

both the 1997 and 2006 standards). PM-2.5 is fine particles of both solid 

particles and liquid droplets, and are believed to pose the largest health 

risks. Sources of fine particles include motor vehicles, power plants, 

wood burning and certain industrial processes (EPA 2011c). Five counties 

are designated as nonattainment areas due to their lead levels. Sources of 

lead emissions include ore and metals processing, and certain aircraft 

operating on leaded gasoline (EPA 2011c). Sixty-one counties are 

designated as nonattainment areas due to their ozone levels. The active 

ingredients, including byproducts, evaluated in this assessment are not 

classified as ozone producers or depleters, and are not expected to 

contribute to ozone air pollutants. APHIS recognizes that the potential 

exists for some incremental increase in ozone production, as well as some 

other types of air pollutants due to the use of combustion engines in the 

course of application of the pesticides under the preferred alternative. 

However, any increase would be minimal when compared to the use of 

combustion engines as part of normal agricultural practices. 

C. Water Quality within the Geographic Area

Several hundred watersheds are within the current quarantine area and 

expanded area described in this EA (appendix 5). A watershed is an area 

that drains to a common waterway, such as a stream, wetland, aquifer, 

ocean, and so on. American Heritage Rivers, created by Executive Order 

13061 (September, 11, 1997) with selection criteria developed by the 

Council on Environmental Quality (CEQ) are designated by EPA, and are 

rivers that represent natural, cultural, and historic resources. Five rivers 
15

designated as American Heritage Rivers flow through areas evaluated in 

this EA (appendix 5).

The Clean Water Act provides a structure for regulating the discharge of 

pollutants into waters and regulates quality standards for surface waters. 

Section 303(d) of the Clean Water Act requires States to develop lists of 

its impaired and threatened waters (stream/river segments, lakes) (EPA 

2011f). Causes for impairment are numerous and include categories such 

as pathogens, metals, salinity, sediments, pesticides, trash, and other 

organic and inorganic compounds. Most of the watersheds for States and 

their respective counties that are considered in this EA have one or more 

impaired waters, meaning that the water is not meeting one or more of its 

designated uses (based on 2010 watershed data except for Virginia where 

data was from 2008; data for Mississippi was poor) (EPA 2011f). Four 

chemicals currently used in the IFA Quarantine Program and three 

chemicals listed under the preferred alternative in this EA are found in one 

or more of these impaired waters. Bifenthrin, chlorpyrifos, and diazinon 

are reported in impaired waters in California; chlorpyrifos and diazinon 

are reported in impaired waters in Oklahoma; and fipronil is reported in 

impaired waters in Louisiana. Not all waters have been assessed in all 

watersheds. 

IV. Environmental Effects

This section of the EA will evaluate the potential impacts of the no action 

and preferred alternative. Risks to human health and the environment of 

each insecticide are summarized in the following sections. The proposed 

insecticides for the IFA quarantine are also used in nurseries to control 

insect pests other than IFA. The potential for impacts to human health are 

going to be greatest for workers and applicators in the IFA program. The 

use of insecticides in the IFA program are restricted to established 

nurseries and sod farms that want to ship commodities out of the current 

quarantine zone. There is the possibility for exposure to the public once 

the treated plants are shipped out of the nursery and delivered for planting. 

Because some of the treated plants could be used in landscaping, there is a 

potential for some exposure to the public by handling treated plants during 

and after planting. Incidental dermal or dietary exposure could occur in 

these situations; however, the risk is reduced by weathering and 

degradation of insecticides during holding and transport, as well as 

binding of program insecticides to soil particles. In addition, treated

commodities do not include any plants that would typically be eaten by 

humans; therefore, risk to the general public through this route of exposure 

would be low. However, the potential for dietary risk from exposure to 

program insecticides through drinking water are discussed for each 

pesticide. Dermal and inhalation risks to the general population would be 

greatest during the time of application but would be very low because 
16

treatments would only occur in nurseries where the public would not be 

present during application. A review of the labels for each insecticide 

offers a range of requirements for personal protective equipment, based on 

the potential risk of each insecticide. All applications made in nurseries to 

comply with the IFA quarantine will be done by qualified individuals and 

in compliance with all label recommendations to ensure applicator and 

worker exposure and subsequent risk is minimized. In some cases, use 

patterns for some formulations proposed in the preferred alternative are 

not currently registered for that particular use; however, APHIS is 

working with the registrants to expand labels for those formulations so 

that they can be incorporated into the quarantine program and nursery 

treatment program. In the interim, only those pesticides labeled for a 

particular use pattern will be used in the IFA quarantine program. 

From an environmental perspective, all treatments are focused on making 

applications to soil whether that occurs in containerized plants or in more 

open areas, such as sod. A majority of the insecticides used in the IFA 

program are nonsystemic3 in nature; therefore, no insecticide plant 

residues would be anticipated for most of the treatments, with the 

exception of treatments using imidacloprid and clothianidin which are 

systemic insecticides. The potential for risks to nontartget organisms 

consuming residues from plants and insects from a broadcast application4

are discussed in the following summaries. 

A. No Action

a. Human Health

Bifenthrin is a synthetic pyrethroid insecticide that acts on the peripheral 

and central nervous system impacting axons, and is effective as a contact 

or ingested compound. Bifenthrin can be used in multiple formulations in 

the IFA program, is incorporated into soil media for containerized plants,

and is not used for any other use patterns. Bifenthrin has moderate acute 

oral toxicity but low dermal toxicity. The reported median lethality value 

(LD50) in mammals ranges from 53.8 to 70.1 mg/kg. Bifenthrin is not 

considered to be a dermal sensitizer or an eye or skin irritant (Wassell et 

al. 2008). Acute effects of the currently used formulations appear to be 

similar or less than the technical active ingredient, based on available data 

on the material safety data sheet for each formulation. Bifenthrin is not 

considered to be a reproductive or developmental toxicant; however, it is 

considered a potential carcinogen, based on the formation of urinary 

bladder tumors when administered at high doses to mice. Risk to ground 

 3 Nonsystemic means that the pesticide remains on the outside of the plant that is treated. By 

comparison, a pesticide that is systemic gets incorporated into the plant that is treated. 4 Broadcast application means the uniform application of a pesticide in an area, typically 

accomplished using a spreader, sprayer, or other type of application technique.

1. Bifenthrin 

(Container 

Use Only)
17

and surface drinking water resources are not expected to be significant for 

the proposed use pattern, based on label restrictions regarding the 

protection of surface water and the environmental fate properties for 

bifenthrin which demonstrate low solubility and a high affinity for binding 

to soil. 

b. Ecological Resources

Bifenthrin has low to slight toxicity to birds, and moderate acute toxicity 

to wild mammals. Significant exposure and risk to nontarget terrestrial 

vertebrates are not expected due to low toxicity and the fact that 

applications are restricted to soil media in containerized plants where 

nontarget organisms would not be expected to forage. Impacts to 

terrestrial invertebrate populations in the environment surrounding the 

commercial nurseries from bifenthrin treatments are not anticipated as 

treatments are made to soil within the containers. Any incidental contact 

by terrestrial invertebrates in these containers could result in toxicity 

because pyrethroid insecticides are toxic to most terrestrial invertebrates. 

Bifenthrin is considered highly toxic to honey bees by oral and contact 

exposure. 

Similar to other pyrethroid insecticides, bifenthrin is considered highly 

toxic to fish and aquatic invertebrates. Toxicity values for both groups of 

organisms range from the low parts per trillion (ppt) to the low parts per 

billion (ppb), depending on the test species and conditions (Solomon et al. 

2001, Meléndez and Federoff 2010). Offsite transport of bifenthrin to 

aquatic habitats is not expected to occur because treatments are restricted 

to containerized media. Any bifenthrin that could move through the 

containerized media would not be at concentrations that could move 

offsite and result in adverse impacts to aquatic resources. Bifenthrin binds 

tightly to soil and has very low solubility, reducing the potential for 

transport and exposure to aquatic organisms. 

c. Environmental Quality

Bifenthrin impacts to soil are not anticipated under the current use pattern 

because it is applied only to containerized plants subject to quarantine 

treatment. Due to the method of application bifenthrin is also not 

expected to runoff or drift from the point of application in quantities that 

could impact aquatic resources because treatments occur only to 

containerized media. Any bifenthrin that could move offsite would not be 

expected to impact surface or groundwater. Bifenthrin has extremely low 

solubility and mobility in soil, suggesting that it would not be a threat to 

ground water (Meléndez and Federoff 2010). Bifenthrin does degrade 

slowly in soil and sediment, based on field terrestrial and aquatic 

dissipation data (Gan et al. 2008, Meléndez and Federoff 2010). 

Dissipation half-lives range from approximately 80 days to greater than 1
18

year under different soil and sediment conditions. Impacts to air quality 

from volatilization are not expected due to the low vapor pressure for 

bifenthrin. Some bifenthrin could occur in the atmosphere during 

application, but will be restricted to the area of treatment because

applications are made using ground sprayers with a large coarse droplet

size that will minimize drift. 

a. Human Health

Chlorpyrifos is an organophosphate insecticide with a mode of action that

occurs primarily through the inhibition of the cholinesterase enzyme. 

Chlorpyrifos is used as an emulsifiable concentrate or wettable powder 

formulation for the treatment of containerized and balled and burlapped 

plants. It may also be used in treating field-grown plants and grass sod 

prior to shipment. Acute oral toxicity is moderate based on median 

lethality values ranging from 60 to 1,000 mg/kg, depending on the test

species. Dermal toxicity is considered low, and the formulations can 

cause moderate eye and moderate to severe skin irritation, depending on 

the formulation being used. Chlorpyrifos is not considered mutagenic, 

teratogenic, or carcinogenic in studies submitted to support registration

(USDA APHIS 2005). Exposure to humans from the contamination of 

groundwater resources is not expected, based on the environmental fate of

chlorpyrifos and label requirements. Labeled ground application buffers

of 25 feet from surface water and spray drift mitigation language on 

chlorpyrifos labels for IFA will reduce the potential for contamination of 

surface drinking water. Spray drift mitigation measures include 

restrictions on droplet size, sprayer boom height, and wind speed 

restrictions. 

b. Ecological Resources

Chlorpyrifos is considered to be moderately to highly toxic to birds, 

depending on the test species (USDA APHIS 2005, EPA 2011a).

Symptoms of nonfatal exposure to birds include cholinesterase depression 

(ChE), weight loss, reduced egg production, and reduced hatchling 

survival. Indirect impacts to mammals and birds that depend on insects as 

part of their diet could occur for those species that forage exclusively in 

areas where chlorpyrifos may be broadcast applied, such as field grown 

plants and sod fields. These types of areas are highly disturbed areas,

particularly grass sod, which is removed after treatment. Wild mammals 

and birds would forage outside of these disturbed areas, therefore, indirect 

impacts would be expected to be minimal. Impacts to terrestrial 

invertebrates, such as worker honey bees, are expected in areas where 

treatment would occur; however, impacts to pollinators is expected to be 

minor as applications are made using ground equipment and to plants that 

would not have flowers present where pollinator exposure would be more 

likely to occur.

2. Chlorpyrifos
19

Chlorpyrifos is highly toxic to fish and aquatic invertebrates with acute 

median lethality values ranging from the low ppt to low ppb range, 

depending on the test species (USDA APHIS 2005, EPA 2011a). 

Exposure and risk to aquatic species will be reduced by adherence to label 

requirements to reduce drift, and by the application of 25-foot buffers 

from aquatic resources.

c. Environmental Quality

Potential effects of chlorpyrifos on air, soil, or water quality would be 

restricted to areas near the site of application. Chlorpyrifos can persist in 

soil and water for several months under certain conditions; however, the 

persistence is generally only for a month or less. This is dependent on the 

organic content of the soil. Chlorpyrifos degrades quickly in the presence 

of light, with a half-life of approximately 3 hours. In water, it will bind 

readily with sediment with aqueous half-lives ranging from 7 to 28 days. 

Labeled application buffers prohibiting treatment in proximity to water 

bodies and spray drift mitigation restrictions will reduce the potential for 

contamination of surface water habitats. Chlorpyrifos can volatilize into 

the atmosphere; however, its persistence is expected to be short, with a 

half-life of only a few hours because of its photolytic sensitivity (Racke 

1993). Chlorpyrifos can impact air quality through drift from broadcast 

ground applications. These impacts would be restricted to areas within the 

nurseries with offsite transport reduced by adherence to label requirements 

regarding the minimization of drift.

a. Human Health

Fenoxycarb is a juvenile hormone agonist that is classified as an insect 

growth regulator. Juvenile hormone is produced naturally by insects and 

is important in their development and reproduction. In this case,

fenoxycarb prevents the larval insects from maturing to an adult. Its use in 

the IFA program is as a bait formulation called Award® that is used for 

making ground-based field applications; it is not used on container-grown 

and balled and burlapped plants or in grass sod production. The current 

registration for fenoxycarb and all associated uses is scheduled to expire in 

December 2012, at which point only reserves in commerce will be 

available for use (EPA 2011b). The technical active ingredient is 

practically nontoxic to mammals in oral, dermal, and inhalation exposures 

(Sullivan 2000a). The formulated material is slightly more toxic than the 

technical material with an oral LD50 value of 4,921 mg/kg, and would be 

classified as slightly toxic. Formulation dermal and inhalation toxicity is 

considered practically nontoxic, with median values greater than the 

highest test concentration. The potential for eye and skin irritation is 

considered minimal to slight for the Award® formulation, and it is not 

considered a skin sensitizer. Fenoxycarb is not a developmental or 

3. Fenoxycarb
20

reproductive toxicant, and has not been shown to be mutagenic. 

Fenoxycarb does show evidence of carcinogenicity, based on liver and 

lung tumors in subchronic and chronic studies using mice (NIH 2011). 

b. Ecological Resources

Toxicity to terrestrial vertebrates, such as wild mammals and birds, is 

expected to be low, based on available data for fenoxycarb. Mammalian 

toxicity data used to evaluate the potential for human health impacts 

demonstrates low toxicity, as well as the oral and dietary toxicity data for 

birds (EPA 2011a). Data for the northern bobwhite and mallard duck 

show no lethal impacts occurring at concentrations greater than the highest 

test concentration in each study. Acute toxicity studies demonstrate low 

toxicity to pollinators, such as adult or larval honey bees (Aupinel et al. 

2007, EPA 2011a). Studies designed to evaluate sublethal impacts to 

honey bees have shown impacts to honey bees; however, treatments were 

made using a liquid formulation under the assumption that applications 

would occur to flowering plants (Thompson et al. 2005, Aupinel et al. 

2007, Heylen et al. 2010). Fenoxycarb applications in the IFA program 

are made using a ground bait formulation where exposure to honey bees 

through foraging on treated flowering plants is not anticipated. There 

could be some impacts to other terrestrial invertebrates, in particular 

during development; however, these impacts would be restricted to the 

area of treatment within a nursery. 

Fenoxycarb toxicity to fish is moderate to high with median lethality 

values ranging from the mid ppb to low part per million (ppm) range for 

warm water and freshwater species (EPA 2011a). Acute toxicity to 

aquatic invertebrates varies in the mid ppb to low ppm range based on 

available data for freshwater and marine invertebrates. Comparative 

chronic toxicity between fish and aquatic invertebrates is significantly 

greater with effect concentrations in the low ppt range for invertebrates 

compared to ppb for fish. Chronic studies using various freshwater 

cladocerans as test organisms have shown impacts to reproduction and 

increased male production (Oda et al. 2005, Tatarazako and Oda 2007, 

Matsumoto et al. 2008). Current label requirements regarding restrictions 

on applications near water and the method of application in the IFA 

program reduce risks to aquatic species. Applications are made using a 

bait formulation, which will minimize drift and any runoff of fenoxycarb 

from treated areas. Any fenoxycarb that would move offsite would be 

primarily as material bound to soil, reducing bioavailability and risk to 

water-column organisms.

c. Environmental Quality

Fenoxycarb impacts to soil, water, and air are expected to be minor and 

restricted to the area of treatment because of the formulation used in the 
21

IFA program and the environmental fate of the insecticide. Fenoxycarb 

degradation in soil appears to be bi-phasic with primary half-lives of less 

than 10 days, and secondary half-lives greater than 80 days under aerobic 

conditions (Sullivan 2010). Fenoxycarb has moderate solubility in water 

but has a strong affinity to bind to soil and sediment, with organic 

partitioning coefficient values ranging from 1,251 to 2,599, depending on

soil types (Sullivan 2010). The tendency to adsorb to soil and sediment 

reduces the risk to surface and groundwater resources with any fenoxycarb 

entering surface water primarily bound to soil in runoff. The primary 

environmental metabolite of fenoxycarb, however, does have greater 

mobility in soil and could impact surface and groundwater resources. Any 

fenoxycarb that may enter surface water is susceptible to microbial 

degradation. The reported aquatic half-life of fenoxycarb under aerobic 

conditions is 19 days, while under anaerobic conditions it is greater than 

1,000 days (Sullivan 2010). Volatilization into the atmosphere from water 

or soil is not expected to occur in quantities that could impact air quality. 

Fenoxycarb is applied as bait consisting of large particles that would not 

be susceptible to drift. The chemical characteristics that determine the 

potential for volatilization show that concentrations in the air would be 

very low. Any material that would volatilize would degrade in less than 6

hours (Sullivan 2010).

a. Human Health

Fipronil is a phenyl pyrazole insecticide that acts by interfering with 

chloride ions passing through the chloride channel resulting in 

overstimulation of the central nervous system. Fipronil is used in the IFA 

program as a granular formulation (i.e., Chipco®) for treatment of 

containers and grass sod. Applications to field grown plants are also 

allowed under a Special Local Need (FIFRA Section 24(c)) pesticide

approval in Tennessee. It is not used on balled and burlapped plants. The 

technical grade material is moderately toxic to mammals in oral and 

inhalation acute toxicity studies with median lethality values of 92 and 

354 mg/kg, respectively (Drew et al. 2009). Fipronil is considered 

practically nontoxic in dermal exposures. The formulations proposed for 

use in the IFA program are considered practically nontoxic in oral, dermal,

and inhalation exposures, based on available data. Eye and skin irritation 

varies from slight to moderate. Fipronil is not mutagenic, however, it is a 

possible human carcinogen because of an increase in thyroid follicular cell 

tumors in the rat. Developmental and reproductive toxicity studies report 

no observable effect levels (NOELs) ranging from less than 

0.10 mg/kg/day to 20 mg/kg/day. Fipronil is neurotoxic to dogs and rats 

in acute and subchronic studies (Drew et al. 2009). Exposure to workers 

and applicators will be reduced by using a granular formulation. Threats 

to groundwater are not anticipated due to the environmental fate of 

fipronil which does not indicate mobility or leaching. There is the 

potential for surface water contamination; however, adherence to label 

4. Fipronil
22

restrictions, including application buffer zones, will minimize the potential 

for contamination of surface water used for drinking water.

b. Ecological Resources

The acute toxicity of fipronil to wild mammals is moderate based on 

available data for studies used to support human health assessments. 

Fipronil toxicity to birds is highly variable. Acute oral toxicity is 

considered low to mallards with LD50 values exceeding 2,000 mg/kg while 

the equivalent endpoint for the northern bobwhite is 11.3 mg/kg 

suggesting high toxicity to upland gamebirds. A similar trend is seen in 

subacute dietary studies where the toxicity is much higher for the northern 

bobwhite compared to the mallard (Tingle et al. 2003). Toxicity to 

terrestrial invertebrates is also variable depending on the test species. 

Fipronil appears to have low toxicity to earthworms however it has been 

shown to be toxic to some beneficial insects (Tingle et al. 2003). 

Impacts to sensitive terrestrial invertebrates would be expected in 

commercial sod applications. These impacts would be restricted to the 

areas of application that are already highly disturbed because the sod is 

grown and then removed for shipment. Risks to wild mammals and birds 

that could forage in these areas would be greatest after treatment but prior 

to harvest. Indirect risks to wild mammals and birds that depend on 

terrestrial invertebrates would not be expected to occur because they

would forage in areas other than the treated areas which are intensively 

managed for sod production and then harvested prior to shipment. 

Fipronil and its degradates are highly toxic to aquatic species. Median 

lethality values for the parent material to fish range from approximately 

42 to 248 ppb in acute exposures (Tingle et al. 2003). Sensitivity to 

aquatic invertebrates is more variable however fipronil is highly toxic to 

aquatic invertebrates with LC50 values ranging from low ppt for midge 

larvae to the low ppb for the freshwater cladoceran (Tingle et al. 2003).

Sediment toxicity is also high for the midge in exposures to fipronil and 

associated metabolites (Maul et al. 2008). Applications adjacent to water 

bodies could result in runoff that could impact aquatic resources. Risk to 

aquatic resources would be greatest for sod applications compared to 

treatments to containerized plants. Label restrictions regarding the 

protection of water bodies with application buffers ranging from 15 to 60 

feet will reduce risk to aquatic resources. In the case of the protection of 

freshwater resources, the application buffer must contain groundcover that 

will also reduce the flow of fipronil-contaminated water from areas of 

treatment to aquatic areas, as well as trap sediment bound fipronil 

particles.
23

c. Environmental Quality

Reported values for field dissipation half-lives are 33 to 75 days for bare 

soil and 12 to 15 days in turf. Under aerobic conditions, organisms 

present in the soil gradually breakdown fipronil. Aerobic soil metabolism 

studies reported the half-life of fipronil in sandy loam to be 122 days with 

the amide and sulfone metabolites accounting for 27 to 38 percent, and 

14 to 24 percent of the total amount of pesticide applied, respectively 

(Tingle et al., 2003). Fipronil binds tightly to soil so runoff from treated 

fields would contain most of the insecticide bound to soil particles. In 

water, the reported solubilities for fipronil are 2.0 to 2.4 ppm (Tingle et al., 

2003). The reported half-life for fipronil under aerobic aquatic conditions 

was 14.5 days. The major metabolite (a sulfide degradate) typically 

represents 74 percent of the total residue after 30 days. Fipronil has a 

relatively low vapor pressure indicating it does not readily volatilize. 

Consequently, drift would be the only expected pathway for movement 

into the air which would be minor because all proposed formulations are 

granular and would not be anticipated to drift from areas of application. 

a. Human Health

Hydramethylnon is an amidinohydrazone insecticide that binds to 

cytochrome in the electron transport system of mitochondria.

Hydramethylnon works as a metabolic inhibitor by blocking the biological 

process in the insect that makes adenosine triphosphate (ATP). ATP is a 

compound required by most biological processes to provide energy for 

life. Hydramethylnon is used in the IFA program on field-grown plants; it 

is not used on container-grown and balled and burlapped plants or in grass 

sod production. It is selectively toxic to insects with chewing or sponging 

mouthparts, and functions as a slow acting stomach toxicant. It is 

relatively nontoxic to insects that use other modes of feeding and to 

insects where exposure is limited to cuticular contact. Toxicity of the 

technical active ingredient is considered moderate in oral exposures with 

median lethality values ranging from 817 to 1,502 mg/kg. Acute toxicity 

from dermal and inhalation exposures are low with a reported inhalation 

median lethality value of 2.9 mg/L, and a value of greater than 2,000 

mg/kg for dermal exposure (EPA 1998). The formulation proposed in the 

IFA program is granular bait which is considered practically nontoxic in 

acute, oral, dermal, and inhalation exposures. The formulation is also not 

considered to be an eye/skin irritant or skin sensitizer. Hydramethylnon is 

not considered to be mutagenic, teratogenic, or a developmental toxicant 

based on studies to support registration that were conducted using the 

technical ingredient. 

Hydramethlynon is classified as a possible carcinogen based on an 

increased incidence in lung adenomas in long-term exposure studies using 

mice. Similar results were not observed in studies using the rat; however,

5. Hydramethylnon
24

impacts to male rats included a decrease in size and atrophy of testes (EPA 

2003a). 

b. Ecological Resources

Hydramethylnon has low toxicity to wild mammals, based on mammalian 

data submitted to support human health assessments. Avian toxicity is 

low determined from available oral and dietary data. The northern 

bobwhite is more sensitive in acute and subacute exposures compared to 

the mallard (EPA 1998). No chronic toxicity data appears to be available 

for birds. Toxicity to terrestrial invertebrates, such as pollinators, is low 

based on contact studies (EPA 2011a). Apperson et al. (1984) showed 

minimal impacts to native ant populations after treatment for IFA with the 

formulation proposed for use in the IFA program. Other field studies have 

shown some impacts to native ant populations, as well as ground-dwelling 

pests, such as cockroaches and crickets (Plentovich et al. 2010). Impacts 

to select terrestrial invertebrates are possible; however, these impacts will 

be minimized by the use of granular bait and would occur only in the area 

of treatment. These impacts are not expected to have indirect effects to 

other animals that depend on insects for prey. The selective nature of the 

bait formulation and the active ingredient will minimize population level 

impacts.

Available aquatic toxicity data for hydramethylnon demonstrates high 

toxicity to most species. Fish median lethality values range from 

100 μg/L for channel catfish to 1.7 mg/L for the bluegill sunfish (EPA 

2011a). Acute toxicity to invertebrates ranges from the low ppb for the 

mysid shrimp to greater than1 ppm for the freshwater cladoceran (EPA 

2011a). Chronic toxicity of the formulation and technical active 

ingredient is high to aquatic invertebrates (EPA, 2011). Hydramethylnon 

is also considered highly toxic to aquatic plants. Risk to aquatic resources 

could occur in cases where applications are made adjacent to shallow 

water bodies. The bait formulation is a granule which will reduce the 

offsite transport of drift. Also, there are label restrictions designed to 

protect aquatic nontarget organisms. This includes wind speed restrictions 

and avoiding conditions which could result in movement into sensitive

areas. 

c. Environmental Quality

The formulation proposed in the IFA program and the environmental fate 

of hydramethylnon suggest that any impacts to soil, water, or air will be 

restricted to the area of application. On soil surfaces, hydramethylnon 

degrades quickly due to its sensitivity to light. Half-lives of less than 

4 days have been reported for soil in biphasic reactions while the 

photolytic half-life in water is less than one day. In the absence of light,

microbial degradation is slow with reported half-lives greater than 1 year 
25

(EPA 1998). Any material that does not degrade will bind tightly to soil 

from the available data suggesting that hydramethylnon is not mobile and 

expected to impact water quality. Impacts to air quality are not expected 

because the formulation is a granule applied by ground equipment which 

will reduce the potential for drift. Hydramethylnon is also not expected to 

volatilize into the atmosphere from soil or water, based on available 

product chemistry data (EPA 1998). 

a. Human Health

Methoprene is an insect growth regulator that mimics the insect juvenile 

hormone which is critical to insect development. Methoprene is used in 

the IFA program on field-grown plants; it is not used on container-grown 

and balled and burlapped plants or in grass sod production. Technical 

methoprene is considered practically nontoxic to mammals in acute oral, 

dermal, and inhalation exposures. Median acute lethality values range 

from 5,000 to 34,000 mg/kg, and dermal and inhalation values are greater 

than 2,000 mg/kg and 20 mg/L, respectively (EPA 1991). The technical 

ingredient is also not considered an eye or skin irritant, and is not a skin 

sensitizer. 

Data for the formulation proposed in the IFA program does not appear to 

be available; however, based on data for the technical active ingredient 

and the granular formulation proposed in the IFA program, the toxicity is 

not anticipated to be significantly greater than the technical material. 

Methoprene is not considered to be a mutagenic or carcinogenic 

compound, and in chronic dosing studies no observable effect levels 

(NOELs) were observed at the upper dosing range in studies designed to 

evaluate reproductive and developmental impacts. Risks to workers are 

low because the toxicity is low and the granular formulation will reduce 

exposure. 

Methoprene is not expected to impact water resources that could be used 

as drinking water. Methoprene is not mobile; therefore leaching into 

groundwater is not anticipated. Threats to surface water are reduced by 

the formulation proposed for use which will minimize drift. Low 

solubility and selective partitioning to soil and sediment will reduce the 

likelihood of methoprene residues in surface water that could be used for 

drinking water. 

b. Ecological Resources

Toxicity of methoprene to wild mammals is low, based on data submitted 

for human health assessments. Methoprene is also considered practically 

nontoxic to birds in acute and subacute exposures with median lethality

values greater than the highest test concentration (EPA 2011a). Longterm avian reproductive studies show effects at 30 ppm for the mallard,

6. Methoprene
26

but not the northern bobwhite where no chronic reproductive effects were 

noted. Methoprene has selective toxicity to terrestrial invertebrates due to 

the mode of action and when an insect may be exposed. Impacts to some 

soil-borne terrestrial invertebrates have been noted and may occur in this 

program; however, based on the method of application and formulation 

used in the IFA program, impacts would be restricted to areas where the 

bait is used for field grown plants (Campiche et al. 2007). 

Pollinator impacts are not anticipated due to the lack of a significant

exposure pathway to insects, such as honey bees, because applications are 

made to the ground using a granular formulation. In addition, available 

data shows that impacts to honey bees, including sublethal impacts, occur 

at doses that would not be expected to occur in the IFA program or 

through the method of application used in those studies (Robinson 1985, 

Deng and Waddington 1997).

Median lethality values for methoprene toxicity to fish range from the low 

ppm for cold water species, such as the trout, to greater than 100 ppm for 

channel catfish suggesting that methoprene is slightly to practically 

nontoxic to fish (EPA 2001, 2011a). Methoprene varies in toxicity to 

aquatic invertebrates depending on the test species. Median lethality 

values range from the low ppb to low ppm which would be classified as 

slightly to highly toxic. Several studies have been published regarding the 

potential impacts of methoprene and its metabolites to amphibians from its

use as a mosquitocide. A summary of acute toxicity data for methoprene 

shows that toxicity to amphibians is low with values greater than the 

highest test concentration which ranged from 1.0 to 10 ppm with no other 

adverse effects noted (EPA 2001). Studies designed to assess the effects 

of methoprene and its metabolites on the development of amphibians have 

shown impacts occurring above the solubility for methoprene in water, or 

at concentrations that could not occur from applications in the IFA 

program (Degitz et al. 2003, Henrick 2007).

c. Environmental Quality

Methoprene degrades quickly in soil under aerobic and anaerobic 

conditions, with half-lives ranging from 10 to 14 days. Methoprene also 

binds tightly to soil and sediment and, due to its low solubility, will 

partition to sediment in cases where it moves offsite from drift or runoff to 

aquatic habitats. In water, methoprene is resistant to hydrolysis but breaks 

down quickly in the presence of light, with half-lives less than 13 days 

(EPA 1991). Methoprene does exhibit properties that suggest a slight 

potential for volatilization into the atmosphere from soil and water 

(Csondes 2004). This effect is reduced by the preference of methoprene to 

bind to soil and water, and any methoprene that will volatilize is 

susceptible to degradation by sunlight. Movement of methoprene from the 
27

site of application from drift will be minimal because it is applied as bait 

and not susceptible to drift when compared to a liquid formulation.

a. Human Health

Pyriproxyfen is part of a group of insecticides (known as insect growth 

regulators) that act as a juvenile hormone analog. Juvenile hormone is 

critical in the development, reproduction, and diapause of insects. It is 

used as an insecticide to prevent larval insects from maturing to adults. 

The product currently used in the IFA program is Distance® which is a 

bait formulation used in field-grown plants; it is not used on containergrown or balled and burlapped plants or in grass sod production. Acute 

toxicity data for the pyriproxyfen active ingredient and the proposed 

formulation demonstrate very low toxicity from oral, dermal, or inhalation 

exposures. Median lethality values (LD/LC50) for all three exposure 

pathways are greater than the highest test concentrations suggesting that 

the formulation is practically nontoxic in acute exposures. Handling the 

formulated product can result in minor eye irritation, but is not a skin 

irritant or skin sensitizer. 

In longer term studies, pyriproxyfen has been shown to have low toxicity 

with NOELs well above any exposures scenarios that could occur in the 

IFA program (Hanson 2009). Pyriproxyfen and its associated metabolites 

are not considered to be carcinogenic or mutagenic, as demonstrated in

available mammalian studies to support registration of the active 

ingredient (Bayoumi et al. 2003, Hanson 2009). Available mammalian 

toxicity data that has been submitted for registration of pyriproxyfen does 

not indicate any effects related to endocrine disruption. The greatest risk 

of exposure will be to workers during application. Applications will only 

be made by certified personnel following all label recommendations 

regarding worker safety. 

b. Ecological Resources

Proposed pyriproxyfen applications are not expected to have adverse 

impacts to fish or wildlife, based on the method of application, the low 

toxicity of the insecticide to most organisms, and program mitigations to 

reduce exposure and risk. Pyriproxyfen has low toxicity to wild mammals 

and birds suggesting little direct risk and, based on the mode of action of 

pyriproxyfen and the small areas of treatment, would not be expected to 

have adverse impacts for those terrestrial organisms that depend on insects 

as prey items. Pyriproxyfen will have some impacts to nontarget 

terrestrial invertebrates; however, these impacts will be restricted to the 

area of treatment and will only impact some invertebrates because of the

selective nature of the insecticide. Available acute contact toxicity data 

for pollinators shows that pyriproxyfen is practically nontoxic to adult 

honey bees (EPA 2011a). Also, no toxicity has been observed in adult 

7. Pyriproxyfen
28

bumblebees or to male production and brood production. However, 

pyriproxyfen may impact larval bumblebee mortality at concentrations 

higher than the application rates used in this program (Mommaerts et al. 

2006). 

Pyriproxyfen toxicity to aquatic organisms is variable with acute toxicity 

above water solubility (0.367 mg/L) for most fish species, suggesting low 

acute risk to aquatic vertebrates (EPA 2011a). Sublethal impacts in acute 

and chronic exposures can occur at concentrations in the low ppb range for 

fish, and in the ppt range for aquatic invertebrates (Sihuincha et al. 2005, 

Matsumoto et al. 2008, EPA 2011a). Median lethal acute effects to 

aquatic invertebrates vary from the middle to upper ppb range, depending

on the test species (EPA 2011a). Direct or indirect risk to aquatic 

organisms through loss of food items is expected to be low because of the 

application method previously described that will reduce the likelihood of 

offsite drift and runoff. 

c. Environmental Quality

Impacts to soil quality from pyriproxyfen applications are not expected, 

because of the location of the treatments and the fate of pyriproxyfen in 

soil. Any contact with soil will be localized and not expected to persist, 

based on field dissipation half-lives ranging from 3.5 to 16.5 days, and 

aerobic soil metabolism half-lives of less than 2 weeks (Sullivan 2000b). 

Pyriproxyfen is not anticipated to have impacts to air quality due to the 

proposed method of application and environmental fate for the insecticide. 

Pyriproxyfen has a low vapor pressure suggesting that volatilization into 

the atmosphere from plants and soil will be minimal. Because it is applied 

as bait, movement out of the area of treatment due to drift is not 

anticipated. Impacts to surface or groundwater are also not anticipated 

due to the low solubility of pyriproxyfen in water, as well as its preference 

to bind to soil and sediment. This will also reduce the potential for 

volatilization from water into the atmosphere, which is considered 

moderate for pyriproxyfen, based on available fate data (Sullivan 2000b).

B. Preferred Alternative

Expansion of bifenthrin use includes applications to field-grown plants, as 

well as balled and burlapped plants and sod that could require treatment in 

the IFA quarantine zone. In addition to its use as a stand-alone active 

ingredient in various formulations, bifenthrin applications may also occur 

in combination with other active ingredients, such as cypermethrin, 

clothianidin, and imidacloprid (which are discussed below). 

1. Bifenthrin

(In-field 

Commodities, 

Balled and 

Burlapped 

Plants, 

Grass Sod)
29

a. Human Health

Expansion of bifenthrin use in the IFA program is not anticipated to have 

significant additional human health risk beyond that discussed in the no 

action alternative. Although increased usage could result in increased 

potential exposure to workers and applicators, the personal protective 

equipment and pesticide label restrictions required for the proposed 

granular formulations reduce exposure and risk as compared to the 

concentrate formulation. Broadcast applications like those proposed for 

field plants and grass sod could increase the potential for drinking water 

contamination compared to container-only applications, as described in 

the no action alternative. However, an increase in risk to ground drinking 

water resources is not expected because of the low solubility and 

extremely low mobility of bifenthrin, suggesting that it would not leach 

into groundwater. Offsite transport into surface water would be very low 

for the granular formulations due to lack of drift. Adherence to label 

restrictions including, in some cases, application buffers will minimize 

transport of bifenthrin and any other active ingredients to surface drinking 

water resources from drift or runoff.

b. Ecological Resources

Expanded use of bifenthrin in the IFA program could result in an increase

in risk to nontarget organisms from bifenthrin exposure, in particular to 

aquatic resources. Expanded treatments to balled and burlapped plants

will not result in increased risk to nontarget organisms beyond that 

previously discussed for containerized media in the no action alternative. 

However, treatments to field grown plants and grass sod would have a 

greater potential risk to nontarget organisms because these applications are 

broadcast applied to fields where exposure would be greater to terrestrial 

and aquatic resources. Impacts to terrestrial invertebrates that may occur 

in the area of broadcast applications would be restricted primarily to the 

treatment area because of the ground-based applications of bifenthrin and 

formulations proposed for use. Increased risk to aquatic resources would 

also be expected; however, label restrictions, including buffers for some 

formulations, will reduce the potential for adverse impacts to aquatic 

resources immediately adjacent to nursery facilities.

c. Environmental Quality

Any impacts described for bifenthrin under the no action alternative would 

be anticipated to be more widespread under the preferred alternative 

because bifenthrin use would expand. 
30

a. Human Health

Cypermethrin is a pyrethroid insecticide that effects the axon of the nerve 

resulting in paralysis (EPA 2005b). Cypermethrin has several agricultural 

and nonagricultural uses to control a variety of insect pests. For the IFA 

program, its proposed use is to treat containers, field-grown plants, and 

grass sod in a formulation that also contains bifenthrin.

The technical active ingredient, cypermethrin, and the proposed 

formulation, Talstar® Xtra, is moderately toxic in oral exposures, but is 

considered practically nontoxic in dermal and inhalation exposures. The 

formulated material is severely irritating to the eye and moderately 

irritating to the skin. It is also considered a mild skin sensitizer. 

Cypermethrin is not considered mutagenic or teratogenic; however, it is 

considered a possible carcinogen because of results from a chronic mouse 

study where benign lung tumors were observed at the highest dose level. 

These levels are well above those expected in this program. Similar 

effects were not observed in other test species in chronic studies 

(McNeilly and Wang 2007). There is data that demonstrate endocrinerelated impacts in vertebrates, but at residues that would not be expected 

to occur in this program. Jin et al. (2011) observed a decrease in 

testosterone levels in male mice dosed at 20 mg/kg of body weight. Wang 

et al. (2011) also observed effects to mice after maternal exposure during 

lactation to male offspring. Doses of 25 mg/kg resulted in reduced serum 

and testicular testosterone levels in male mice that returned to normal as 

they reached maturity; however, a reduction in testicular weights and 

tissue effects remained unchanged. These values are in the effect range 

for studies that have been submitted to support the registration of 

cypermethrin. Risk to human health, and in particular workers and 

applicators, will be low due to the toxicity of cypermethrin and the 

granular formulation proposed for use. Exposure to cypermethrin in 

drinking water is not anticipated. 

The proposed formulation is a granule which will minimize the potential 

for offsite drift. Cypermethrin has very low water solubility and 

preferentially binds to soil and sediment, suggesting that it would not be 

susceptible to leaching into groundwater and would not be present in any

runoff to surface water bound to soil particles.

b. Ecological Resources

Cypermethrin has low acute and chronic avian toxicity with reported acute 

median lethal doses and chronic no observable effect concentrations 

(NOECs) greater than the highest test concentration (EPA 2005b). 

Toxicity is high to most terrestrial invertebrates, including honey bees;

however, the granular formulation proposed for use in the IFA program 

will reduce potential offsite impacts due to the low drift potential. 

2. Cypermethrin
31

Broadcast applications would be expected to have impacts to some 

terrestrial invertebrates; however, these impacts would be restricted to the 

area of application and, in the case of soil-borne invertebrates, would be 

minimized by the affinity for the insecticide to bind to soil, reducing 

bioavailability over time (Hartnik and Styrishave 2008). The impacts that 

could occur to some terrestrial invertebrates from IFA treatment with 

cypermethrin is not expected to pose an indirect risk to terrestrial 

vertebrates that depend on invertebrates for prey, in particular for 

container treatments. In the case of field applications, vertebrates would 

be expected to forage over areas greater than the area of treatment. 

Cypermethrin is considered highly toxic to aquatic invertebrates and 

vertebrates with reported median lethality values in the low ppt to low ppb

range, depending on the test species, although fish were slightly less 

sensitive when compared to aquatic invertebrates (Solomon et al. 2001, 

EPA 2005b). Acute and chronic risk to aquatic habitats is low because of 

the granular formulation proposed for use which reduces the potential for 

drift. Runoff will also be low because cypermethrin has low water 

solubility and will bind to soil and sediment reducing bioavailability to 

aquatic organisms. In addition, label language regarding the protection of 

aquatic habitats will reduce the risk to aquatic biota.

c. Environmental Quality

Cypermethrin is not expected to cause adverse impacts to soil, water, or 

air quality due to the method of application and the environmental fate of 

the insecticide. Cypermethrin breaks down in soil under aerobic and 

anaerobic conditions, with half-lives of less than 65 days (EPA 2005b). 

As discussed previously, there is the potential for impacts to soil-borne 

invertebrates; however, this will be restricted to the area of treatment 

because of the granular formulation proposed for use. Cypermerthrin has 

very low water solubility and a high binding affinity to soil and sediment 

that would result in a very low probability of surface or groundwater 

contamination. Cypermethrin that would move offsite as drift and enter 

surface water would dissipate quickly from the water column due to its 

low water solubility and affinity for sediment particles. The rapid 

partitioning of pyrethroid insecticides from water to sediments has been 

observed in field applications, as well as laboratory data (Crossland 1982). 

In the field, half-lives are less than a day under a variety of conditions 

(Roessink et al. 2005, He et al. 2008). Physical and chemical 

characteristics of cypermethrin preclude significant volatilization into the 

atmosphere. Cypermethrin would also not be present in the atmosphere as 

drift because the proposed formulation is a granule and would not be 

expected to remain in the atmosphere after application.
32

a. Human Health

Clothianidin is a systemic pesticide that belongs to the neonicotinoid 

insecticide class which acts on the nicotinic acetylcholine receptor 

affecting the central nervous system in insects. Clothianidin is proposed 

for use in this program using the formulation, Aloft® SC, which also 

contains the insecticide bifenthrin. It will be used to treat field plants and 

sod, but not container-grown or balled and burlapped plants. Clothianidin 

has low acute oral toxicity to rats but is moderately toxic to mice, with a 

reported median lethality value of 425 mg/kg (EPA 2003b). Acute dermal 

and inhalation toxicity of the active ingredient and the proposed 

formulation is low with median lethality values exceeding the highest 

concentration tested. Clothianidin is not considered to be teratogenic, 

mutagenic, or carcinogenic, based on available mammalian studies. The 

formulation proposed for use in this program is a slight to moderate eye 

irritant and slight skin irritant and is considered a skin sensitizer, based on 

data available on the material safety data sheet. 

Clothianidin does exhibit chemical fate properties that suggest mobility in 

soil and could contaminate drinking water. Conservative estimates of 

exposure from surface and groundwater contamination do not present any 

risk to the general population. Risk to groundwater is further reduced by 

avoiding applications in areas with a high water table and/or permeable 

soils. Risk to surface water will be reduced by following label restrictions 

regarding application buffers from surface water resources.

b. Ecological Resources

Clothianidin has low to moderate toxicity to wild mammals and is 

considered practically nontoxic to birds, based on oral and dietary 

exposures (EPA 2003b, 2011a). Conservative assumptions regarding the 

ingestion of contaminated prey items, such as insects, demonstrate very 

low risk to wild mammals and birds that may forage on treated fieldgrown plants in nurseries. Indirect risk to vertebrate populations from the 

loss of prey items is not anticipated from the treatment of fields because 

they are not typically large areas, they are already disturbed due to other 

activities, and not exclusive habitats for foraging. Clothianidin is toxic to 

honey bees and, because of its systemic action, may impact pollinators due 

to residues in pollen and nectar. Studies designed to assess these types of 

impacts in bumblebees have shown that maximum clothianidin residues 

measured in the field had no observed effects on foraging ability or colony 

health (Franklin et al. 2004). Clothianidin was linked to a 2008 bee death 

incident in Germany. The combination of conditions that occurred in that 

incident (i.e., application method, weather, use pattern) are not expected in 

this program; therefore, that type of exposure and risk to honey bees and 

pollinators are not likely to occur. Label restrictions also reduce bee 

exposure by restricting applications on blooming, pollen, shedding, and

3. Clothianidin
33

nectar-producing parts of the plant if bees are anticipated to forage in the 

area within a 5-day window after treatment. 

Acute toxicity to fish is low with median lethality values greater than the 

highest test concentration. Acute toxicity to aquatic invertebrates is more 

variable with median lethality values ranging in the low ppb range for 

some freshwater and marine invertebrates, such as mysid shrimp and 

chironomids (i.e. midges) to greater than 100 ppm for standard test 

species, such as the freshwater cladoceran (EPA 2003b, 2011a). 

Adherence to label precautions, including a 25-foot buffer, will reduce the 

risk to aquatic biota.

 

c. Environmental Quality

Clothianidin applications to field-grown plants and grass sod are not 

expected to have adverse impacts to soil, water, or air quality beyond the 

area of treatment. Clothianidin degradation in soil is slow with laboratory 

and field studies documenting half-lives of approximately 148 days to 

greater than two years. Clothianidin used in combination with bifenthrin 

as proposed in this program would result in impacts to soil invertebrates;

however, these impacts would be restricted primarily to the areas of 

application which are managed nurseries. Clothianidin is considered to be 

highly mobile in soil and could contaminate water in areas where 

applications are made in close proximity to surface water or to permeable

soils with a high groundwater table. The label for the formulation 

proposed in this program requires a 25-foot application buffer from 

various water bodies. Avoiding applications to soils that are permeable 

will also reduce the likelihood of groundwater contamination. Any 

clothianidin that would reach water would be susceptible to degradation 

by light with a reported half-life of less than 1 day. Degradation of 

clothianidin from hydrolysis or biological factors is slower because 

clothianidin is resistant to hydrolysis and has an aquatic metabolism halflife value of approximately 1 month (EPA 2003b). Impacts to air quality 

are not anticipated due to the low vapor pressure of clothianidin and 

method of application which includes the use of ground equipment. 

a. Human Health

Permethrin is a pyrethroid insecticide that has a varied toxicology profile.

Proposed use in the IFA program is on and around hay and beehives, but

not for treatment of container-grown, field-grown, or balled and burlapped 

plants and grass sod. Acute mammalian toxicity of permethrin is variable 

for the active ingredient with oral LD50 values ranging from approximately 

40 mg/kg to greater than 3,580 mg/kg. Dermal toxicity is considered low 

with LD50 values of greater than 2,000 mg/kg for the rabbit and rat

(Kinard et al. 2005). Acute inhalation is also low (LC50 >23.5 mg/L), as is 

the potential for acute eye and dermal irritation (Kinard et al. 2005). The 

4. Permethrin
34

formulation proposed for use, Gardstar®, has moderate acute oral toxicity 

to mammals with a median lethality value of 1,490 mg/kg. Similar to the 

technical active ingredient, dermal and inhalation toxicity is very low with 

values reported as greater than the highest concentration tested in those 

studies. The formulation is considered slightly irritating to the skin but is 

not a skin sensitizer; however, it is corrosive to the eye according to data 

on the material safety data sheet. Chronic toxicity studies of permethrin 

have demonstrated low toxicity in prenatal developmental and 

reproductive studies. Based on the review of studies submitted to EPA for 

reregistration, the no observable adverse effect level (NOAEL) in these 

types of studies ranged from 50 mg/kg/day to 600 mg/kg/day (Kinard et 

al. 2005). Long-term toxicity studies that assessed carcinogenicity using 

the dog, rat, and mouse reported NOAEL values ranged from 36.9 to 

316.1 mg/kg/day, depending on species and endpoint. Permethrin has 

been established as a possible human carcinogen by EPA; however, the 

exposure levels where those types of effects occurred were high, and the 

effect was only seen in mice, not rat or dog studies. 

b. Ecological Resources

Nontarget terrestrial vertebrates, such as birds, do not appear to be 

sensitive to permethrin exposure, based on the low LD50 toxicity values 

for several bird species that range from greater than 2,000 to greater than 

23,000 mg/kg (Rexrode and Meléndez 2005). Chronic toxicity to birds is 

also low with NOEC values ranging from 25 to 500 ppm, which were the 

highest test concentrations used in each study. Permethrin is toxic to 

honey bees, as well as other beneficial insects; however, the risk will be 

localized because proposed applications will occur as a soil drench around 

hay bales and adjacent to beehives. 

Aquatic organisms are more sensitive to permethrin than other test 

organisms, based on the range of toxicity values to marine and freshwater 

fish and invertebrates (EPA 2011a). A large number of freshwater and 

marine aquatic toxicity studies have been conducted using permethrin with 

a result of high acute and chronic toxicity to aquatic fauna. Generally, fish 

are less sensitive than invertebrates with fish LC50 values ranging from the 

high ppt to mid ppb range, depending on the species and respective life 

stage, study duration, and test conditions. The marine and freshwater 

aquatic invertebrate toxicity range is lower with reported LC50/EC50 values 

ranging from the low ppt to low ppb range (Solomon et al. 2001, Rexrode 

and Meléndez 2005). Permethrin chronic toxicity to fish and aquatic 

invertebrates is also high, with NOEC values ranging from the low ppt to 

low ppb range for fish and aquatic invertebrates, respectively. The 

proposed use of permethrin in this program as a soil drench to small 

localized areas around hay bales and in proximity to bee colonies will 

reduce the potential amount of permethrin that could runoff or drift into 

aquatic areas. As a soil drench, large droplets can be used that will 
35

mitigate drift concerns. Runoff to aquatic areas will be minimized due to 

the preferential binding affinity of permethrin to soil and sediment, and 

label restrictions regarding surface water protection.

c. Environmental Quality

The potential for impacts to soil, water, and air quality beyond the site of 

application are not anticipated for the proposed use of permethrin in the 

IFA program. There would be potential impacts to soil-borne terrestrial

invertebrates in the area where the soil drench would occur; however,

because these would not be broadcast applications the impacts would be 

localized at the point of treatment. Degradation half-lives in soil under 

aerobic conditions are typically less than 40 days; however, under 

anaerobic conditions may exceed 204 days (Rexrode and Meléndez 2005). 

In water, similar differences in half-lives occur between aerobic and 

anaerobic conditions. Permethrin has low water solubility and a strong 

affinity for binding to soil and sediment. Risk to groundwater is not 

anticipated, based on the fate of permethrin in water and the proposed 

application methods for the IFA program. Permethrin may impact surface 

water from drift; however, the use of large droplets and localized 

treatments will minimize the potential for drift. Permethrin that may enter 

surface water from runoff will be bound to soil particles or, once in the 

water, will rapidly bind to sediment. This is reflected in the aquatic field 

dissipation data for permethrin with reported half-lives of approximately 3

days or less in studies conducted using pond water. Impacts to air quality 

are not anticipated because applications will be made using large droplets 

that would not be expected to remain in the atmosphere. In addition, the 

chemical fate information for permethrin, in particular the vapor pressure

value, indicates that permethrin would not be expected to volatilize into 

the atmosphere in quantities that could result in negative impacts to air 

quality (Rexrode and Meléndez 2005).

a. Human Health

Imidacloprid belongs to a class of insecticides called neonicotinoids which 

act by binding directly to the acetylcholine binding receptor. Technical 

and formulated imidacloprid has low to moderate acute oral mammalian 

toxicity with median toxicity values ranging from 400 to greater than

2,000 mg/kg. The technical material, as well as several formulations, are 

considered practically nontoxic from dermal or inhalation exposure 

(Anatra-Cordone and Durkin 2005). Acute lethal median toxicity values 

are typically greater than 2,000 mg/kg and 2.5 mg/L for dermal and 

inhalation exposures, respectively. Its proposed use in the IFA program is 

in two different formulations that are premixed with other active 

ingredients. The first formulation, Allectus®, is proposed for use in balled 

and burlapped plants with bifenthrin, and in the second formulation, 

DiscusTM, it is premixed with cyfluthrin and would be used in field-grown

5. Imidacloprid
36

plants, balled and burlapped plants, and grass sod; neither formulation 

would be used in container-grown plants. The toxicity and risk of 

bifenthrin and cyfluthrin are discussed individually elsewhere in this 

section. Available acute toxicity data for formulations similar to those 

proposed in the IFA program but with higher percentages of each active 

ingredient suggest low acute oral, dermal, and inhalation toxicity. Both 

formulations are not considered to be a skin sensitizer, and have low risk 

as a skin and eye irritant. Available data for imidacloprid and associated 

metabolites suggest a lack of mutagenic, carcinogenic, or genotoxic 

effects at relevant doses. Developmental-, immune-, and endocrinerelated effects have been observed in some mammal studies. In all cases,

the noted effects were observed at doses above maternal effects in the case 

of developmental studies, and at concentrations and durations not expected 

in the IFA program (Anatra-Cordone and Durkin 2005). 

Potential risks to human health are restricted, primarily, to applicators. As 

proposed in this program, the use of granular formulations will minimize 

oral, dermal, and inhalation exposure during application. Adherence to 

label language regarding personal protective equipment and the low oral, 

dermal, and inhalation toxicity of these two formulations will minimize 

risk to workers who would be making applications with either 

formulation. Imidacloprid does have chemical properties that suggest it 

could be a threat to groundwater. Avoiding applications in areas where a 

high water table is present and soils that are highly permeable will reduce 

the potential for groundwater contamination. 

b. Ecological Resources

Imidacloprid is considered to have moderate toxicity to wild mammals and

is considered toxic to birds, with acute oral median lethal toxicity values 

ranging from 41 to 152 mg/kg. Concerns have been raised about potential 

lethal and sublethal effects to honey bees and other pollinators. Median 

lethal toxicity values of imidacloprid have been based upon oral or contact 

exposure. Laboratory and field studies of honey bees indicate a lack of 

adverse effects at test concentrations comparable to realistic exposure 

scenarios, and adverse health impacts to hives only with greater exposures 

(USDA APHIS 2008). However, recent laboratory studies assessing 

sublethal impacts of imidacloprid have demonstrated impacts to honey

bees when exposed to lower levels of imidacloprid and the insect 

pathogen, Nosemia spp. (Pettis et al. 2012). Broadcast applications of 

DiscusTM would pose the greatest risk to pollinators and other sensitive

terrestrial invertebrates due to the method of applications and presence of 

the broad spectrum insecticide, cyfluthrin. Labeled restrictions regarding 

the protection of honey bees during application will help reduce exposure 

and risk. Exposure is further reduced in sod treatments as honey bees 

would not be expected to be attracted to these areas due to a lack of 

flowering plants.
37

Exposure to wild mammals and birds from applications of imidacloprid 

and associated residues is not expected to occur at levels that could result 

in significant risk. The terrestrial insects that feed upon vegetation of 

those host plants that have been treated with these applications are likely 

to be impacted, but the effects would be restricted to the areas of 

treatment. Indirect impacts to vertebrate populations that depend on insect 

prey are not anticipated. All treatments take place in commercial 

nurseries. Areas of sod that could be treated with the DiscusTM formulation 

would be expected to have some impacts to nontarget terrestrial 

invertebrates; however, the impacts would be restricted primarily to areas 

of treatment where sod would be removed for shipment. Vertebrates that 

might forage in these areas would also forage outside of the treatment area 

since their foraging range would not be restricted to highly disturbed areas 

within the nurseries. 

Imidacloprid has low toxicity to aquatic organisms including fish, 

amphibians, and some aquatic invertebrates. Acute toxicity to fish and 

amphibians is low with acute median lethal concentrations typically 

exceeding 100 mg/L (Anatra-Cordone and Durkin 2005, EPA 2011a). 

Chronic toxicity to fish is in the low ppm range, depending on the test 

species and endpoint. Aquatic invertebrates are more sensitive to 

imidacloprid when compared to fish, with acute median toxicity values in 

the low ppb range to greater than 100 mg/L, depending on the test species 

(Anatra-Cordone and Durkin 2005, EPA 2011a). Aquatic vertebrates and 

invertebrates can be exposed through runoff or drift from the site of 

application. Drift is not considered a significant route of exposure because

the formulations proposed for use are granules. Runoff could occur and 

would be greatest for the DiscusTM formulation because it is proposed for 

field use. Conservative estimates of potential residues that could runoff 

from the proposed applications are not expected to have any direct impacts 

to aquatic vertebrate populations. Indirect risk through the loss of aquatic 

prey items is also not anticipated, based on the potential range of 

concentrations and toxicity data for aquatic invertebrates.

c. Environmental Quality

Imidacloprid persistence in soil can range from 27 to 229 days, based on 

field dissipation studies (Anatra-Cordone and Durkin 2005, Fossen 2006). 

Imidacloprid does not adsorb strongly to soil particles. Imidacloprid is 

soluble in water and has a half-life under natural light of less than 5 hours 

in water, but is stable to hydrolysis. Based on the chemical properties of 

imidacloprid, there is the potential for leaching into groundwater 

resources. Adherence to label requirements, as well as the avoidance of 

applications to permeable soils and/or areas where the water table is high

will ensure the protection of groundwater. Imidacloprid is not expected to 

impact air quality because the method of application will not result in 
38

significant drift. Volatilization to the atmosphere is also not anticipated, 

based on the chemical properties of imidacloprid.

a. Human Health

Cyfluthrin is a synthetic pyrethroid insecticide with broad spectrum 

activity. The mode of toxic action occurs by causing the sodium channels 

to stimulate nerves to produce repetitive discharges. Muscle contractions 

are sustained until a block of the contractions occurs. Nerve paralysis can 

occur at high levels of exposure. The DiscusTM formulation, which is a 

mixture of imidacloprid and cyfluthrin, will be used on field-grown plants, 

balled and burlapped plants, and grass sod, but not in container-grown 

plants, as discussed in the previous section of this document on 

imidacloprid. The acute oral median lethal toxicity of cyfluthrin is 

considered to be low to moderate in mammals. Inhalation and acute 

dermal toxicity are considered to be low. The formulation of cyfluthrin to 

be used in the program is of comparable or lower acute toxicity than the 

active ingredient. The program applications pose no evident dermal 

irritation or sensitization, but may result in mild eye irritation. An acute 

neurotoxicity study using the rat resulted in a decrease in motor activity at 

10 mg/kg/day, with a resulting NOEL of 2 mg/kg/day (EPA 2005a).

Reproductive and developmental toxicity studies in rats found a maternal 

NOEL of 3 mg/kg/day, and a developmental NOEL of 10 mg/kg/day. 

Cyfluthrin is not considered to pose mutagenic or carcinogenic risks (EPA 

1997). Cyfluthrin risk to surface or groundwater will be reduced due to 

the formulation proposed for use and the environmental fate of 

pyrethroids. Drift is not anticipated because the formulation is a granule,

and movement into groundwater is unlikely due to the very low mobility 

and solubility of cyfluthrin. The DiscusTM formulation proposed for use in 

the IFA program contains the active ingredient imidacloprid which does 

have chemical properties that suggest mobility in soils and possible 

leaching into groundwater. Avoiding applications to permeable soils or in 

areas where a high water table is present will reduce the risk to 

groundwater that could be used as drinking water.

b. Ecological Resources

The acute oral median lethal toxicity of cyfluthrin is considered to be low 

to moderate for mammals. Inhalation and acute dermal toxicity are 

considered to be low. The formulation of cyfluthrin to be used in the 

program is of comparable or lower toxicity than the active ingredient. 

Cyfluthrin is considered to be practically nontoxic to birds, with acute oral 

median lethal toxicity values greater than 2,000 mg/kg (EPA, 2011). 

Chronic toxicity to birds is also low, based on reproductive studies 

conducted with the mallard and northern bobwhite, with no effect 

concentrations greater than 250 ppm (EPA 2011a).

6. Cyfluthrin
39

The broad-spectrum activity of cyfluthrin results in high toxicity to most 

insects, including pollinators. The 48-hour contact median lethal dose for 

honey bees is 0.037 μg/bee (EPA 2011a). Pollinators, such as honey bees,

should not be impacted; however, because applications are made using a 

granular formulation, no applications to flowering parts of plants are 

anticipated, and the insecticide is not systemic in plants. Impacts to soilborne terrestrial invertebrates are not expected for applications to balled 

and burlapped plants, although impacts to field grown plants and grass sod 

would be anticipated where applications occur. Commercial nurseries are 

intensively managed and their environment is not likely to be favorable to 

native, terrestrial invertebrates.

Cyfluthrin is highly toxic to fish and very highly toxic to most aquatic 

invertebrates (EPA 2011a). The greatest risk to aquatic resources is 

through drift from cyfluthrin applications. Cyfluthrin runoff is not 

expected to be significant to aquatic resources because this type of 

insecticide binds tightly to soil and has very low solubility, thereby 

reducing the potential for transport and exposure to most aquatic 

organisms. There is the potential for risk to sediment-dwelling 

invertebrates; however, adherence to label recommendations and the lack 

of drift will reduce the potential for aquatic residues that could result in 

impacts to aquatic invertebrate populations.

c. Environmental Quality

Cyfluthrin impacts to soil, water, and air quality are expected to be 

minimal, based on the environmental fate and label requirements for 

application. Cyfluthrin half-lives in soil are variable depending on pH and 

organic matter. Laboratory and field dissipation half-lives range from 

approximately 30 to 94 days. Once cyfluthrin reaches the soil, it binds 

very tightly to soil particles, and is not considered to be water soluble. Its 

high affinity for soil and low solubility suggest that any cyfluthrin that 

reaches an aquatic resource will be soil bound or will partition very 

rapidly to the sediment. The lack of mobility suggests that ground water 

contamination will not be a concern. Surface water quality could be 

impacted from drift during applications; however, several mitigation 

measures are stated on the label to protect surface water quality. 

Cyfluthrin will only occur in the atmosphere during application, but will 

dissipate rapidly and is not expected to volatilize back into the atmosphere 

based on its chemical properties. 

a. Human Health

Lambda cyhalothrin is a pyrethroid insecticide with a mode of action 

similar to those previously described in this EA. The proposed use in the 

IFA program would be to containers, balled and burlapped plants, field7. Lambda 

cyhalothrin
40

grown plants, and sod using the formulation Scimitar® GC, which is a 

liquid concentrate. The technical active ingredient has moderate acute 

oral toxicity with LD50 values of 56 to 79 mg/kg (Durkin 2010). Dermal 

and inhalation toxicity is also moderate with values of 623 mg/kg and 

0.065 mg/L, respectively. Similar data for the formulation proposed in the 

IFA program shows much lower toxicity with oral, dermal, and inhalation 

values greater than the highest concentration tested and would be 

considered practically nontoxic. The formulation proposed for use is not 

considered to be an eye irritant, but is a slight skin irritant. Exposure of 

the concentrated material to the skin can cause parasthesia which is a 

slight tingling or numbness sensation. Lambda cyhalothrin is not a 

developmental or reproductive toxicant at relevant exposure levels, and is 

not considered mutagenic or carcinogenic. Adherence to label directions 

and program requirements will minimize the potential exposure and risk to 

applicators and workers who would be at risk in the proposed applications 

to various commodities in commercial nurseries under quarantine. 

b. Ecological Resources

Lambda cyhalothrin is considered practically nontoxic to birds, based on 

available data for the bobwhite quail and mallard duck (EPA 2011a). 

Chronic toxicity is also low with NOEC values greater than the highest 

test concentration in long-term reproductive studies. Lambda cyhalothrin 

is considered highly toxic to honey bees and other pollinators and, due to 

its broad spectrum activity, would be expected to impact terrestrial 

invertebrates in areas of treatment. 

Lambda cyhalothrin is very highly toxic to aquatic vertebrates and 

invertebrates in acute and chronic exposures. Acute and chronic toxicity 

to freshwater and marine fish are from the low ppt to low ppb range (EPA 

2011a). Aquatic invertebrates are more variable in their sensitivity to 

lambda cyhalothrin, based on available data. Acute median lethality 

values range from 1 ppt for mosquito larvae and freshwater amphipods to 

2.4 ppb for midge larvae. Current labeling for the proposed formulation 

require a 25-foot application buffer from water bodies for all uses and 

additional drift mitigation measures, such as droplet size requirements, 

vegetative filter strips, temperature inversion, and wind speed restrictions 

for sod uses which will reduce the exposure and risk to aquatic fauna. 

c. Environmental Quality

Impacts to soil, water, and air quality are not anticipated for the proposed 

use of lambda cyhalothrin beyond the areas of application within 

commercial nurseries. The half-life of lambda cyhalothrin in soil is less 

than 50 days under aerobic conditions, and the insecticide will bind 

strongly to soil based on available data regarding partitioning between soil 

and water. In water, lambda cyhalothrin has very low water solubility 
41

and, due to its preferential binding to soil and sediment, will not occur in 

solution. Under aerobic conditions in water the half-life is approximately 

21 days. Due to the low solubility and high affinity for soil, lambda 

cyhalothrin is not expected to contaminate groundwater. Surface water 

contamination is also minimized due to the environmental fate of lambda 

cyhalothrin and label restrictions that require buffer zones, as well as other 

measures, depending on the use pattern, that will reduce offsite drift and 

runoff. The reported vapor pressure for lambda cyhalothrin indicates that 

it will not volatilize into the atmosphere and impact air quality, and will 

only occur in the atmosphere near the ground in areas where applications 

occur in the nurseries.

V. Cumulative Impacts

Cumulative impacts are those impacts on the environment which result 

from the incremental impact of a proposed action when added to other 

past, present, and reasonably foreseeable future actions regardless of what 

agency (Federal or non-Federal) or person undertakes such other actions. 

Cumulative impacts can result from individually minor but collectively 

significant actions taking place over a period of time. 

The insecticides proposed to be added to the list of available insecticides

for the IFA quarantine program are also used in a wide variety of 

residential and/or commercial applications throughout the area covered in 

the affected environment of this EA, based on information collected from 

pesticide labels (available in the EPA Pesticide Product Label System 

(EPA 2011d)). Land use summaries for each State discussed in the 

affected environment of this EA and the broad spectrum activity for a 

majority of the IFA insecticides suggests that urban and agricultural use of 

these products also occurs. These products are used to treat multiple pests,

including IFA, at a greater frequency of use than that used in the IFA 

quarantine program. In addition, several of the proposed insecticides are 

also part of pest management and eradication programs supported by 

APHIS, some of which overlap in counties where IFA treatments could 

occur. (Information for APHIS plant pest programs is available on the

APHIS website:

http://www.aphis.usda.gov/plant_health/plant_pest_info/index.shtml.) 

For example, cypermethrin is listed as a chemical option in the Asian 

citrus psyllid (ACP), and the boll weevil and pink bollworm moth 

eradication programs. In addition, the ACP program has several chemical 

treatment options with some of those overlapping with insecticides being 

proposed, or currently used, in the IFA program (clothianidin, 

imidacloprid, chlorpyrifos, bifenthrin, zeta-cypermethrin, cyfluthrin and 

permethrin). Additional pesticide active ingredients available in the boll 

weevil program that are part of the IFA program include permethrin, 
42

chlorpyrifos, bifenthrin, cyfluthrin, lambda-cyhalothrin and zetacypermethrin. In the pink bollworm program, chlorpyrifos and permethrin 

are additional pesticide active ingredients that are either part of the current 

IFA program or being proposed for use. Chlorpyrifos use is also listed as 

a treatment option for the European gypsy moth and light brown apple 

moth programs. While several APHIS programs have pesticide-active 

ingredients that are part of the current and proposed new list for IFA, 

cumulative impacts from this program relative to other APHIS programs 

would be expected to be minimal. In the case of the boll weevil and pink 

bollworm programs, applications are confined to cotton fields; insecticides 

are only used in rare cases where other treatments, such as trapping, sterile 

insect technique, and mating disruption will not result in eradication 

within a particular field. Recent insecticide treatments in both of these 

programs have been minimal or have not occurred in some years due to 

the success of other control measures. In addition, programs like the light 

brown apple moth are restricted to California, thus the potential for 

cumulative impacts would be restricted to those areas where there is 

overlap without impact on the remaining States that are part of the IFA 

quarantine. The pink bollworm program is only active in select counties 

within California, New Mexico, Arizona, and Texas, and no chemical 

treatments occurred in 2011. There is the possibility that some nurseries 

treating for ACP may also treat for IFA; however, there is uncertainty in 

which treatments would be used in each program, and when treatments

would occur in relation to each other. Both programs offer multiple 

chemical options from which to select in meeting the requirements of the 

quarantine. 

 

In the case of the IFA quarantine, all program insecticide treatments will 

only occur in commercial nurseries where ground disturbance and other 

activities (e.g., pesticide use and fertilizer application) are routine 

activities unrelated to IFA. Cumulative impacts to human health and 

terrestrial resources (e.g., soil and nontarget fauna from the proposed 

pesticides) are expected to be minor within the current quarantine as 

applications for IFA already take place. The newer active ingredients 

appear to have equal or less risk to human health, and will be confined 

primarily to applicators that treat plants prior to shipment. Some of the 

proposed new insecticides (e.g., imidacloprid and clothianidin) do have a 

greater risk of mobility and could impact drinking water; however, label 

language will reduce the risk of these insecticides to aquatic resources. 

Geographic areas where the IFA quarantine does not currently exist, but 

covered in this EA, would expect to see increased insecticide use due to 

the IFA quarantine once the county becomes part of the IFA quarantine. 

Increased pesticide loading would be anticipated within the nurseries; 

however, adherence to label language will reduce the potential for 

significant cumulative impacts beyond those already occurring with other 

activities in the nursery. There is the potential for cumulative impacts to 

aquatic resources that are adjacent to nursery operations. Offsite transport
43

of pesticide runoff into receiving streams from applications to 

containerized plants, as well as broadcast applications in nurseries, have 

been noted in several studies (Stearman and Wells 1997, Briggs et al. 

1998, Gan and Lee 2005, Gan 2006). Two products proposed for new or 

expanded use in this EA, permethrin and bifenthrin, have been shown to 

occur in runoff from nurseries (Gan 2006). Bifenthrin, in particular, is 

linked to impaired water bodies in counties in California that are part of 

the IFA quarantine. Treatments using bifenthrin in proximity to these 

impaired water bodies could have cumulative impacts in addition to the 

residues that already occur. Due to temporal and spatial uncertainty in 

bifenthrin use patterns, it is difficult to quantify the potential for additional 

pesticide loading and impacts. The same is true for chlorpyrifos and 

fipronil which are listed as causes for impairment for one or more water

bodies within the current quarantine. In other cases where impairment is 

due to reasons other than the proposed pesticides, there is the concern for 

mixture toxicity which could result in cumulative impacts to water quality 

and aquatic resources. Water bodies that are impaired for reasons other 

than pyrethroid and organophosphate insecticide toxicity may also be 

impacted with increased pesticide use because impacts could be a result of 

mixture effects. Water quality data from areas within the current IFA 

quarantine, as well as outside the quarantine, show pesticide mixtures to 

be a common occurrence in surface water with varying impacts to aquatic 

organisms (Gilliom et al. 2007). Mixtures, including pesticides currently 

used and proposed for use in the IFA program, can have additive or 

greater than additive toxicity to aquatic and terrestrial organisms (Deneer 

2000, Lydy and Austin 2004, Key et al. 2007, Trimble et al. 2009, 

Svendsen et al. 2010). In the case of pyrethroids, such as permethrin and

cyfluthrin, they may also have slightly antagonistic toxicity to aquatic 

biota, therefore there is uncertainty in the ability to quantify the potential 

cumulative impacts of these mixtures (Brander et al. 2009). Many of the 

proposed new formulations have buffer zone restrictions, as well as other 

protective label language regarding aquatic resources that will minimize 

the potential for any cumulative impacts to aquatic resources. 

 

Incremental cumulative impacts to human health and the environment are 

expected to be minor within the nurseries to be treated and, in particular, 

to those already under the IFA quarantine. The additional pesticides that 

can be used do not appear to result in additional risk to human health 

beyond those currently used in the program. Cumulative impacts from 

offsite transport through runoff and drift are more difficult to quantify due 

to the geographic area considered in the EA, and the uncertainty regarding 

spatial and temporal use patterns of pesticides and other contaminants in 

aquatic resources. In cases where the nurseries are not adjacent to aquatic 

resources, no cumulative impacts would be expected. In cases where 

aquatic resources are in proximity to treatment areas, the method of 

application, the formulations proposed, label restrictions, and the fate of 
44

most insecticides proposed for use will reduce the potential for cumulative 

impacts to any aquatic resources.

VI. Other Environmental Considerations

A. Executive Orders

Consistent with Executive Order (EO) 12898, “Federal Actions to Address 

Environmental Justice in Minority Populations and Low-Income 

Populations,” APHIS considered the potential for the proposed action to 

have any disproportionately high adverse human health or environmental 

effects on any minority populations and low-income populations. IFA 

quarantine treatments will only take place in nurseries that occur within 

the current quarantine area, and have regulated articles that require 

treatment prior to shipment to areas that are not part of the quarantine. 

These nurseries are established commercial facilities where applications 

will only be made in the nurseries and not in locations where the public 

(including minority and low-income populations) would be present. The 

potential for the offsite movement of pesticide is reduced by the proposed 

use patterns of each formulation, and adherence to all label language 

designed to protect the public, as well as workers and applicators, within 

the nurseries. Because chemical treatments are being applied only in 

nurseries, APHIS has determined that the human health and environmental 

effects from the proposed applications are minimal and are not expected to 

have disproportionate adverse effects to any minority or low-income 

populations. 

Consistent with EO 13045, “Protection of Children from Environmental 

Health Risks and Safety Risks,” APHIS considered the potential for 

disproportionately adverse environmental health and safety risks to 

children resulting from the proposed action. All proposed treatments will 

occur within production nursery facilities where the public, including 

children, would not be present. Drift to areas adjacent to production 

nurseries where children could be present is not expected because the 

methods of application and formulations used have a low potential to 

move offsite through the atmosphere. The lack of exposure to this portion 

of the population would suggest that risks to children from the proposed 

application of insecticides would not be expected to result in adverse 

impacts. Items shipped out of the quarantine area after treatment and then 

moved to areas where children may occur is another potential route of 

exposure. 

Exposure of IFA treatments to children is greatest in soil which is where 

IFA resides and is the focus of treatments in the quarantine program. 

Exposure to children would be low in these situations because the soil 

associated with the roots of the plant that may have residues would be 
45

localized relative to the amount of untreated soil in the area if plants are 

transplanted. Two of the proposed formulations contain active 

ingredients, imidacloprid and clothianidin, that are considered systemic. 

Therefore, plants treated with these pesticides would contain some 

residues. Use of both insecticides in the IFA program would not be to 

plants grown for food, thus reducing the potential for dietary exposure that 

could result in adverse effects to children and the general population. In 

addition, treated plants with any IFA insecticide may be held after

treatment at the nursery prior to shipping where degradation and 

weathering would occur, further reducing exposure. Based on the 

available data regarding the toxicity of each insecticide and their proposed 

use pattern, APHIS determined that no disproportionate effects to children 

are anticipated as a consequence of implementing the preferred alternative

B. Threatened and Endangered Species

Section 7 of the Endangered Species Act and its implementing regulations 

require Federal agencies to ensure that their actions are not likely to 

jeopardize the continued existence of endangered or threatened species or 

result in the destruction or adverse modification of critical habitat. APHIS 

is preparing a biological assessment (BA) that evaluates the potential for 

impacts to listed species under the jurisdiction of the Fish and Wildlife 

Service (FWS). The potential for affecting endangered and threatened 

species exists primarily within the nurseries where pesticide treatments 

would occur. The FWS BA addresses the potential for impacts to 

approximately 606 listed species that have been identified to occur within 

the current quarantine area and the expanded areas described in this EA. 

Effects determinations and mitigation measures have been proposed for 

those species where co-occurrence between treatments and habitat may 

occur. Any conservation measures decided upon will be incorporated into 

the compliance agreements required by the nurseries. Concurrence with 

FWS on the BA will ensure that adequate protective measures are in place 

for the protection of listed species that may co-occur with program 

activities. 
46

VII. Listing of Agencies and Persons

Consulted

U.S. Department of Agriculture

Animal and Plant Health Inspection Service

Plant Protection and Quarantine

CPHST Gulfport Lab

3505 25th Ave. 

Gulfport, MS 39501

U.S. Department of Agriculture

Animal and Plant Health Inspection Service

Policy and Program Development 

Environmental and Risk Analysis Services

4700 River Road, Unit 149

Riverdale, MD 20737

U.S. Department of Agriculture

Animal and Plant Health Inspection Service

Plant Protection and Quarantine

Emergency and Domestic Programs

Environmental Compliance

4700 River Road, Unit 150

Riverdale, MD 20737
47

VIII. Appendices

Appendix I. Observed Damage to Wildlife by IFA

Animal (Type) Noted Effects Reference

Gopher tortoise Direct predation on hatchlings (Allen et al. 2004)

Alligator mississippiensis Infested nests received less maintenance by 

females resulting in hatchlings w ith low er birth 

rate

(Allen et al. 2004)

Burmese python Eggs susceptible to IFA in laboratory studies (Diffie et al. 2010)

Loggerhead sea turtle (federally

listed endangered species)

Eggs susceptible to IFA in laboratory studies (Diffie et al. 2010)

Diamondback terrapin (IUCN Red 

List1 as low er risk or near 

threatened)

Eggs susceptible to IFA in laboratory studies (Diffie et al. 2010)

Yellow belly slider Eggs susceptible to IFA in laboratory studies (Diffie et al. 2010)

Eastern painted turtle Eggs susceptible to IFA in laboratory studies (Diffie et al. 2010)

Yellow rat snake Eggs susceptible to IFA in laboratory studies (Diffie et al. 2010)

Vireo griseus (black capped vireo 

is federally endangered; w hiteeyed vireo)

Protection of nests from IFA predation 

increased nest survival by 10%

(Campomizzi et al. 2009)

Orthalicus reses reses (Say) 

(Stock Island tree snail)

Federally listed as threatened; Florida State 

listed as endangered; extinct from the w ild; 

IFA thought to be a major factor in its 

extinction

(Wojcik et al. 2001)

Cottontail rabbit (Sylvilagus 

floridanus (Allen))

Mortality (33 to 75%) of new born rabbits 

when exposed to fire ants

Hill, E.P., 1970. Observations 

of imported fire ant predation 

on nestling cottontails. Proc. 

Southeast. Assoc. Game Fish 

Comm. 23: 171–181 (cited in 

(Wojcik et al. 2001))

Box turtle (Terrapene carolina 

triunguis (Agssiz))

Mortality of adult turtles due to IFA stings Montgomery, W.B., 1996. 

Predation by the fire ant, 

Solenopsis invicta, on the 

three-toed box turtle, 

Terrapene carolina triunguis. 

Bull. Chicago

Herpetol. Soc. 31: 105–106. 

(cited in (Wojcik et al. 2001))

Toad (Bufo houstonensis

(Sanders))

IFA stings caused mortality of young toads; 

federally listed as endangered

Freed, P.S. and K. Neitman,

1988. Notes on predation on 

the endangered Houston 

toad, Bufo houstonensis.

Tex. J. Sci. 40: 454–456.

(cited in (Wojcik et al. 2001))

1 IUCN = International Union for Conservation of Nature and Natural Resources. The IUCN Red List provides information on 

the conservation status of plant and animal species (http://www.iucnredlist.org/).
48

Appendix II. Land Resource Regions Overlapping with the Geographic Areas Covered in this 

Environmental Assessment

Land Resource Region 

(LRR) Overlapping with 

Federal Quarantine1

States or Parts Thereof 

Under Federal Quarantine 

and Fall within the LRR 

States or Parts Thereof 

within the LRR Not Under 

Federal Quarantine

Soil Orders and Suborders Found in the LRR

C—California subtropical 

fruit, truck, and specialty 

crop region

California (one county under 

quarantine and parts of 2 other 

counties)

There are four dominant soil orders: Alfisols, Entisols, 

Mollisols, and Vertisols. 

There are six dominant soil suborders: Xeralfs,

Xererts, and Xerolls; Fluvents, Orthents, and Ochrepts are 

found in the flood plains and alluvial fans and are soils 

important for agricultural purposes.

D—Western range and 

irrigated region 

California – one county; New 

Mexico - one county

There are three dominant soil orders: Aridisols, Entisols, and 

Mollisols. 

There are five dominant soil suborders: Argids, Calcids, 

Orthents, Ustolls, and Xerolls.

G—Western Great Plains 

Range and Irrigated Region

Texas (small portion of the 

northw est corner), Oklahoma 

(very small portion)

Colorado, Kansas, Montana, 

Nebraska, New Mexico, North 

Dakota, South Dakota, 

Wyoming

There are tw o dominant soil orders: Entisols, Mollisols.

There are four dominant soil suborders: Ustorhents, 

Torriorhents, Haplustolls, and Argiustolls.

H—Central Great Plains 

w inter w heat and range 

region

Oklahoma, Texas Colorado, Kansas, Nebraska, 

New Mexico

The dominant soil order is Mollisols, but significant acreages 

of Alfisols, Entisols, and Inceptisols are also present. The 

dominant soil suborder is Argiustolls. Other suborders 

include Haplustolls, Ustipsamments, Calciustolls, Paleustolls, 

and Paleustalfs.

I—Southw est plateaus and 

plains range and cotton 

region

Texas There are five dominant soil orders: Alfisols, Aridisols, 

Inceptisols, Mollisols, and Vertisols. 

There are five dominant soil suborders: Calcids, Ustalfs, 

Ustolls, Usterts, and Ustepts.

J—Southw estern prairies 

cotton and forage region

Oklahoma, Texas Kansas There are four dominant soil orders: Mollisols, Entisols, 

Alfisols, and Vertisols. 

There are four major soil suborders: Paleustalfs,

Haplustolls, Haplusterts, and Argiustolls.

N—East and central farming 

and forest region 

Alabama, Arkansas, Georgia, 

North Carolina, Oklahoma, South 

Carolina, Tennessee, Virginia 

Illinois, Indiana, Kentucky, 

Missouri, Ohio, Pennsylvania, 

West Virginia; very small areas 

in Kansas, Maryland, New York

There are four dominant soil orders: Alfisols, Entisols, 

Inceptisols, or Ultisols. 

There are four major soil suborders: Dystrudepts, 

Hapludalfs, Hapludults, and Paleudults.

O—Mississippi delta cotton 

and feed grains region

Arkansas, Louisiana, Mississippi, 

Tennessee

Missouri, very small areas in 

Kentucky and Illinois

There are four dominant soil orders: Alfisols, Vertisols, 

Inceptisols, or Entisols. 
49

There are five major suborders: Aqualfs, Aquerts, Epiaqualfs, 

Epiaquerts, and Udifluvents.

P—South Atlantic and gulf 

slope cash crops, forest, 

and livestock region

Alabama, Arkansas, Florida, 

Georgia, Louisiana, Mississippi, 

North Carolina, Oklahoma, South 

Carolina, Tennessee, Texas, 

Virginia 

Illinois, Kentucky, Missouri There are five major soil orders: Alfisols, Entisols, 

Inceptisols, Ultisols, or Vertisols. There are 14 major soil 

suborders: 

Dystruderts, Dystrudepts, Fragiudalfs, Eutrudepts, 

Fluvaquents, Fraglossudalfs, Hapludalfs, Hapluderts, 

Hapludults, Kandiudults, Kanhapludults, Paleudalfs, 

Paleudults, and

Quartzipsamments.

T—Atlantic and Gulf Coast 

low land forest and crop 

region 

Alabama, Florida, Georgia, 

Louisiana, Mississippi, North 

Carolina, South Carolina, Texas, 

Virginia

Delaw are, Maryland, New 

Jersey

There are five dominant soil orders: Alfisols, Entisols, 

Histosols, Spodosols, and Ultisols.

There are five dominant soil suborders: Aqualfs, Aquents, 

Aquults, Psamments, and Udults.

U—Florida subtropical fruit, 

truck crop, and range region

Florida The dominant soil order is Entisols, and significant areas of 

Alfisols and Histosols. 

There are three dominant suborders: Aqualfs, Aquents, and 

Psamments. 1

Land resource regions (LRRs) are geographically associated major land resource areas (MLRAs) which approximate broad agricultural market regions (USDA–NRCS). 

LRRs are categorized by capital letters. Major land resource areas (MLRAs) are geographically associated land resource units (LRUs). MLRAs are described in the 

Agriculture Handbook 206, and include brief descriptions of total area of the MLRA in a particular State; list of major cities, highways, and culturally significant Federal- and 

State-owned lands within each MLRA; and information on physiography, geology, climate, w ater, soils, biological resources, and land use in the MLRA. 

(Source: (USDA NRCS 2006)
50

Appendix III. Major Uses of Land (2007) for States within the IFA 

Quarantine and the Expanded Geographic Area Covered in this

Environmental Assessment

State Cropland

Grassland 

Pasture 

and Range

Forestuse 

Land

Specialuse 

Areas

Urban 

Areas

Miscellaneous 

Other Land

Total 

Land 

Area1

------------------------------------- 1,000 acres -------------------------------------

Alabama 3,104 2,642 22,587 1,535 1,140 1,468 32,476 

Arkansas 8,240 3,293 18,596 1,568 589 1,039 33,324 

California2 9,550 27,524 26,983 25,377 5,166 5,213 99,814 

Florida 2,760 5,558 15,649 5,008 4,052 1,486 34,513 

Georgia 4,619 1,292 24,267 2,073 2,465 2,344 37,060 

Louisiana 4,435 1,860 14,142 1,975 1,088 4,380 27,880 

Mississippi 5,556 2,055 19,579 958 607 1,265 30,020 

New Mexico2 2,367 52,122 14,977 6,477 493 1,232 77,668 

North 

Carolina 4,843 1,231 18,037 2,858 2,357 1,849 31,175 

Oklahoma 12,840 18,707 7,620 1,731 736 2,312 43,947 

South 

Carolina 2,001 795 12,646 1,081 1,230 1,517 19,270 

Tennessee 6,019 2,093 13,913 2,072 1,594 688 26,379 

Texas 34,115 101,735 17,159 6,220 4,646 3,676 167,550 

Virginia 3,251 2,463 15,350 1,662 1,555 1,059 25,340 

1

Miscellaneous areas, such as marshes, open swamps, bare rock areas, deserts, rural residential areas, and other uses not 

inventoried.

2

Values for California and New Mexico are for the entire State; however, only eight counties in California and one county in 

New Mexico are part of the geographic scope of this assessment.

Source: (USDA ERS 2007, Nickerson et al. 2011).
51

Appendix IV. Counties within the IFA Quarantine and the Expanded 

Geographic Area Covered in this Environmental Assessment 

that are Designated as Nonattainment Areas for One or More 

Common Air Pollutants Tracked by the Environmental 

Protection Agency (EPA)

State or Part Thereof Under 

IFA Quarantine and the States 

and Counties Considered in 

the EA1

Number of Counties 

with Nonattainment 

Status1

County with Nonattainment 

Status Pollutant2

Alabama (all 67 counties are under 

IFA quarantine) 5

Jackson, Jefferson, Shelby, Walker PM-2.5 1997

Jefferson, Shelby, Walker PM-2.5 2006

Pike Lead 2008

Arkansas (part or all of 33 counties 

are under IFA quarantine; This EA 

considers all 75 counties)

0 No counties listed

California (part or all of 3 counties 

are under IFA quarantine; This EA 

considers 8 counties out of 57)

7

Los Angeles Lead 2008

Los Angeles, Orange, Riverside, 

San Bernardino PM-2.5 1997

Imperial, Los Angeles, Orange, 

Riverside, San Bernardino PM-2.5 2006

Imperial, Los Angeles, Orange, 

Riverside, San Bernardino PM-10

Imperial, Los Angeles, Orange, 

Riverside, San Bernardino, San 

Diego, Ventura

8-Hr Ozone

Florida (all 66 counties are under IFA 

quarantine) 1 Hillsborough Lead 2008

Georgia (all 156 counties are under 

IFA quarantine) 27

Barrow , Bartow , Bibb, Carroll, 

Catoosa, Cherokee, Clayton, Cobb, 

Cow eta, De Kalb, Douglas, Fayette, 

Floyd, Forsyth, Fulton, Gw innett, 

Hall, Heard, Henry, Monroe, 

New ton, Paulding, Putnam, 

Rockdale, Spalding, Walker, Walton

PM-2.5 1997

Barrow , Bartow , Carroll, Cherokee, 

Clayton, Cobb, Cow eta, De Kalb, 

Douglas, Fayette, Forsyth, Fulton, 

Gw innett, Hall, Henry, New ton, 

Paulding, Rockdale, Spalding, 

Walton

8-Hr Ozone

Louisiana (all 60 counties are under 

IFA quarantine) 5

Ascension, East Baton Rouge, 

Iberville, Livingston, West Baton

Rouge

8-Hr Ozone

Mississippi (all 82 counties are under 

IFA quarantine) 0 No counties listed

New Mexico (1 county out of 33 is 

under IFA quarantine) 1 Dona Ana PM-10

North Carolina (60 counties – all or 10 Cataw ba, Davidson, Guilford PM-2.5 1997
52

part thereof – are under IFA 

quarantine; this EA considers all 100 

counties)

Cabarrus, Gaston, Iredell, Lincoln, 

Mecklenburg, Row an, Union 8-Hr Ozone

Oklahoma (8 counties fall w ithin the

IFA quarantine; this EA considers all 

77 counties)

0 No counties listed

South Carolina (all 46 counties are 

under IFA quarantine) 1 York 8-Hr Ozone

Tennessee (55 counties are w ithin 

the IFA quarantine; this EA considers 

all 93 counties)

7

Anderson, Blount, Hamilton, Knox, 

Loudon, Roane PM-2.5 1997

Anderson, Blount, Knox, Loudon, 

Roane PM-2.5 2006

Sullivan Lead 2008

Texas (188 counties fall w ithin the 

IFA quarantine; this EA considers all 

254 counties)

18

Collin Lead 2008, 

2009

El Paso PM-10

Brazoria, Chambers, Collin, Dallas, 

Denton, Ellis, Fort Bend, Galveston, 

Harris, Johnson, Kauf man, Liberty, 

Montgomery, Parker, Rockw all, 

Tarrant, Waller

8-Hr Ozone

Virginia (2 counties fall w ithin the IFA 

quarantine; this EA considers all 95 

counties)

4 Arlington, Fairfax, Loudoun, Prince 

William

PM-2.5 1997; 

8-Hr Ozone

 

1 The IFA quarantine area includes States of: Alabama, Florida, Georgia, Louisiana, Mississippi, South Carolina, and parts 

of Arkansas, California (part of Los Angeles and Riverside County and the entire county of Orange), New Mexico (one 

county), North Carolina, Oklahoma, Tennessee, Texas, and Virginia. The geographic range of this EA includes the current 

quarantine area, as well as areas into which IFA is likely to expand, based on research done by Korzukhin et al. (2001). The 

expanded region includes the entire State of Arkansas, North Carolina, Oklahoma, Tennessee, Texas, and Virginia. It also 

includes several additional counties in California (San Bernardino, Ventura, Santa Barbara, San Diego, and Imperial) and 

the entire county of Los Angeles, and Riverside in California. 2 PM-10 = Particulate matter 10 micrometers in diameter or less; PM-2.5 = Particulate matter 2.5 micrometers in diameter or 

less; the year follow ing a pollutant is the version of the standard used at the time of the measurement; 8-Hr Ozone is 

measured by taking “the 3-year average of the fourth-highest daily maximum 8-hour average ozone concentrations 

measured at each monitor within an area over each year must not exceed 0.08 ppm”.

Source: (EPA 2011c)
53

Appendix V. Number of Watersheds and Watersheds Containing 

Waters Impaired with Chemicals Used in the IFA Program

State or Part Thereof 

within the Current 

Federal Quarantine

Number of Watersheds within the 

Current Quarantine Area1 and within 

the Expanded Geographical Region 

Covered in this EA3

Chemicals Used or Proposed 

For Use in The IFA Program 

Found in Impaired Waters

Alabama (entire State) 52 Chlorpyrifos

Arkansas (part of State) 22 (est.) 1

59 total 3

None listed

California (part of State) 4 (est.) 1

40 total

Calleguas Watershed (Ventura Co.):

Chlorpyrifos, Diazinon, Bifenthrin; 

Los Angeles Watershed (Los 

Angeles and Ventura Co.):

Diazinon; 

Newport Bay Watershed (Orange 

Co.): Chlorpyrifos, Diazinon; 

Salton Sea Watershed (Imperial, 

Riverside, San Bernardino, San 

Diego Co.): Chlorpyrifos, Diazinon;

San Diego Watershed (San Diego 

Co.): Diazinon; 

San Gabriel Watershed (Los 

Angeles, Orange, and San 

Bernardino Co.): Diazinon;

Santa Clara Watershed (Los 

Angeles, Santa Barbara, and 

Ventura Co.): Chlorpyrifos, 

Diazinon; 

Santa Maria Watershed (Santa 

Barbara Co.): Chlorpyrifos 

Florida (entire State) 54 3 None listed

Georgia (entire State) 52 3 None listed

Louisiana (entire State) 60 3 Fipronil

Mississippi (entire State) 59 3 None listed

New Mexico (Dona Ana

County)

4 None listed

North Carolina (part of State) 28 (est.) 1

58 total 3

None listed

Oklahoma (part of State) 20 (est.) 1

67 total 3

Lower Canadian-Walnut Watershed, 

Deep Fork Watershed, Lower 

Cimarron-Skeleton Watershed: 

Chlorpyrifos 

Lower Verdigris Watershed, 

Polecat-snake Watershed:

Diazinon

Puerto Rico (entire territory) 11 3 Pesticides listed but type not 

specified

South Carolina (entire State) 38 3 None listed

Tennessee (part of State) 23 (est.) 1

60 total 3

None listed

Texas (part of State) 112 (est.) 1 None listed
54

210 total 3

Virginia (part of State) 4 (est.) 1

53 total 3

None listed

1

The (est.) indicates the number is an estimate; w e are unable to precisely overlay the States or counties under partial IFA 

quarantine with watershed and national w ildlife refuge areas using the maps and resources consulted. The estimates 

provide enough information for the purposes of this document. 

2

The number of federally listed threatened or endangered species is unique for each National Wildlife Refuge but is not 

unique across refuges; a species may be found in multiple refuges.

3

The total number of watersheds per State was obtained from EPA’s Surf your watershed 

(http://cfpub.epa.gov/surf/locate/index.cfm).

 

Sources: (EPA 2011e, FWS 2011a, b)
55

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