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Environmental Assessment Rangeland Grasshopper and Mormon 

Cricket Suppression Program

ARIZONA

EA Number: AZ-20-01

Site-Specific

Graham and Gila County portion within the San Carlos Apache Reservation;

Mohave County Hualapai Reservation;

Cochise County portion of Coronado National Forest – Winchester Mountains

Prepared by:

Animal and Plant Health Inspection Service

3640 East Wier Ave. 

Phoenix, Arizona 85040

May 6, 2020
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Table of Contents

I. Need for Proposed Action...................................................................................................... 4

A. Purpose and Need Statement .............................................................................................. 4

B. Background Discussion ...................................................................................................... 5

C. About This Process............................................................................................................. 7

II. Alternatives............................................................................................................................ 7

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

B. Insecticide Applications at Conventional Rates or Reduced Agent Area Treatments with Adaptive 

Management Strategy (Preferred Alternative).......................................................................... 8

C. Experimental Treatments Alternative ............................................................................... 10

III. Affected Environment.......................................................................................................... 10

A. Description of Affected Environment............................................................................... 12

1. Human Health ................................................................................................................... 13

2. Nontarget Species .......................................................................................................... 14

3. Socioeconomic Issues.................................................................................................... 17

4. Cultural Resources and Events ...................................................................................... 17

5. Special Considerations for Certain Populations ............................................................ 18

IV. Environmental Consequences.............................................................................................. 19

A. Environmental Consequences of the Alternatives............................................................ 19

1. No Action Alternative.................................................................................................... 19

2. Insecticide Applications at Conventional Rates or Reduced Agent Area Treatments with Adaptive 

Management Strategy ........................................................................................................... 20

3. Experimental Treatments Alternative ............................................................................ 25

B. Other Environmental Considerations................................................................................ 25

1. Cumulative Impacts....................................................................................................... 27

2. Executive Order No. 12898, Federal Actions to Address Environmental Justice in Minority 

Populations and Low-Income Populations........................................................................... 28

3. Executive Order No. 13045, Protection of Children from Environmental Health Risks and Safety Risks

........................................................................................................................................ 29

4. Tribal Consultation ........................................................................................................ 30

5. Executive Order 13186, Responsibilities of Federal Agencies to Protect Migratory Birds 

........................................................................................................................................ 30

6. Endangered Species Act ................................................................................................ 30

7. Bald and Golden Eagle Protection Act .......................................................................... 31

8. Additional Species of Concern ...................................................................................... 32

9. Fires and Human Health Hazards.................................................................................. 32

10. Cultural and Historical Resources ................................................................................. 32

V. Literature Cited .................................................................................................................... 33

VI. Listing of Agencies and Persons Consulted......................................................................... 44
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Appendices

Appendix 1: FY 2020 Guidelines for Treatment of Rangeland for the Suppression of Grasshoppers and 

Mormon Crickets, USDA APHIS PPQ Western Region...........................................

Appendix 2: Map of Affected Environment............................................................

Appendix 3: Map of Proposed Action Areas Covered by the Two Environmental Assessments for the State of 

Arizona. (EA# AZ-20-01 and AZ-20-02)..................................................................

Appendix 4: Map of the Hualapai Tribe. Proposed Action Area. ..........................

Appendix 5: Map of the San Carlos Apache Tribal Proposed Action Area. ..........

Appendix 6: Map of the Coronado National Forest Proposed Action Area. ..........

Appendix 7: FWS/NMFS Correspondence .............................................................

Appendix 8: Public Comments and APHIS Response .................................

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Site-Specific Environmental Assessment 

Rangeland Grasshopper and Mormon Cricket Suppression Program

ARIZONA

Site-Specific

Mohave County Hualapai Reservation

Graham and Gila County portion within the San Carlos Apache Reservation 

Cochise County portion of Coronado National Forest – Winchester Mountains

I. Need for Proposed Action

A. Purpose and Need Statement

An infestation of grasshoppers or Mormon crickets may occur in may occur on rangeland in Mohave 

County on the Hualapai Indian Reservation; on rangeland in Graham and Gila County, San Carlos 

Apache Reservation and on rangeland in Cochise County, Coronado National Forest - Winchester

Mountains, portion of Arizona. The Animal and Plant Health Inspection Service (APHIS) may, upon 

request by land managers or State departments of agriculture, conduct treatments to suppress 

grasshopper infestations as part of the Rangeland Grasshopper and Mormon Cricket Suppression 

Program (program). The term “grasshopper” used in this environmental assessment (EA) refers to both 

grasshoppers and Mormon crickets, unless differentiation is necessary.

Populations of grasshoppers that trigger the need for a suppression program are normally considered on 

a case-by-case basis. Participation is based on potential damage such as stressing and/or causing the 

mortality of native and planted range plants or adjacent crops due to the feeding habits of large 

numbers of grasshoppers. The benefits of treatments include the suppressing of over abundant 

grasshopper populations to lower adverse impacts to range plants and adjacent crops. Treatment would 

also decrease the economic impact to local agricultural operations and permit normal range plant 

utilization by wildlife and livestock.

The goal of the proposed suppression program analyzed in this EA is to reduce grasshopper populations 

below an economic infestation level1 in order to protect rangeland ecosystems and/or cropland adjacent 

to rangeland. This environmental assessment (EA) analyzes potential environmental consequences of the

proposed action and its alternatives. This EA applies to a proposed suppression program that would take

place from 04/01/20 to 09/30/20 on rangeland in Mohave County on the Hualapai Indian Reservation; on 

rangeland in Graham and Gila County, San Carlos Apache Reservation and on rangeland in Cochise

County, Coronado National Forest - Winchester Mountains, portion of Arizona. This EA is prepared in 

accordance with the requirements under the National Environmental Policy Act of 1969 (NEPA) (42 

United States Code § 4321 et. seq.) and the NEPA procedural requirements promulgated by the Council 

on Environmental Quality, United States Department of Agriculture (USDA), and APHIS.

1 The “economic infestation level” is a measurement of the economic losses caused by a particular population level of grasshoppers to the infested rangeland. 

This value is determined on a case-by-case basis with knowledge of many factors including, but not limited to, the following: economic use of available 

forage or crops; grasshopper species, age, and density present; rangeland productivity and composition; accessibility and cost of alternative forage; and 

weather patterns. In decision-making, the level of economic infestation is balanced against the cost of treating to determine an “economic threshold” below 

which there would not be an overall benefit for the treatment. Short-term economic benefits accrue during the years of treatments, but additional long-term 

benefit may accrue and be considered in deciding the total value gained by treatment. Additional losses to rangeland habitat and cultural and personal values 

(e.g., aesthetics and cultural resources), although a part of decision-making, are not part of the economic values in determining the necessity of treatment. 
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B. Background Discussion

Rangelands provide many goods and services, including food, fiber, recreational opportunities, and 

grazing land for cattle (Havstad et al., 2007; Follett and Reed, 2010). Grasshoppers and Mormon 

crickets are part of rangeland ecosystems, serving as food for wildlife and playing an important role in 

nutrient cycling. However, grasshoppers and Mormon crickets have the potential to occur at population 

levels, particularly during high levels referred to as outbreaks (Belovsky et al., 1996), that result in 

competition with livestock and other herbivores for rangeland forage and can result in damage to 

rangeland plant species.

In rangeland ecosystem areas of the United States, grasshopper populations can build up to outbreak 

levels despite even the best land management and other efforts to prevent outbreaks. At such a time, a 

rapid and effective response may be requested and needed to reduce the destruction of rangeland 

vegetation. In some cases, a response is needed to prevent grasshopper migration to cropland adjacent to 

rangeland. 

APHIS conducts surveys for grasshopper populations on rangeland in the Western United States, 

provides technical assistance on grasshopper management to land owners and managers, and may 

cooperatively suppress grasshoppers when direct intervention is requested by a Federal land 

management agency or a State agriculture department (on behalf of a State or local government, or a 

private group or individual. APHIS’ enabling legislation provides, in relevant part, that ‘on request of 

the administering agency or the agriculture department of an affected State, the Secretary, to protect 

rangeland, shall immediately treat Federal, State, or private lands that are infested with grasshoppers or 

Mormon crickets’... (7 U.S.C. § 7717(c) (1). The need for rapid and effective response when an 

outbreak occurs limits the options available to APHIS. The application of an insecticide within all or 

part of the outbreak area is the response available to APHIS to rapidly suppress or reduce grasshopper 

populations and effectively protect rangeland. 

In June 2002, APHIS completed an Environmental Impact Statement (EIS) document concerning 

suppression of grasshopper populations in 17 Western States (Rangeland Grasshopper and Mormon 

Cricket Suppression Program, Environmental Impact Statement, June 21, 2002). The EIS described the 

actions available to APHIS to reduce the destruction caused by grasshopper populations in Arizona, 

California, Colorado, Idaho, Kansas, Montana, Nebraska, Nevada, New Mexico, North Dakota, 

Oklahoma, Oregon, South Dakota, Texas, Utah, Washington, and Wyoming. During November 2019, 

APHIS published an updated EIS to incorporate the available data and analyze the environmental risk of 

new program tools. 

APHIS has authority under the Plant Protection Act of 2000 (PPA) (7 United States Code (U.S.C.) § 

7701) to take actions to control and minimize the economic, ecological, and human health impacts that 

harmful plant pests can cause. APHIS uses this authority to protect U.S. agriculture, forests, and other 

natural resources from harmful pest species.

Section 417 of the PPA (7 U.S.C. § 7717) authorizes APHIS’ efforts to minimize the economic impacts

of grasshoppers. Section 417(a) states that subject to the availability of funds, the Secretary “shall carry 

out a program to control grasshoppers and Mormon crickets on all Federal lands to protect rangeland.”

Section 417(c) (1) states that “Subject to the availability of funds pursuant to this section, on request of 

the administering agency or the agriculture department of an affected State, the Secretary, to protect 

rangeland, shall immediately treat Federal, State, or private lands that are infested with grasshoppers or 

Mormon crickets at levels of economic infestation, unless the Secretary determines that delaying 

treatment will not cause greater economic damage to adjacent owners of rangeland.” Section 417(c)(2) 
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states, “In carrying out this section, the Secretary shall work in conjunction with other Federal, State, 

and private prevention, control, or suppression efforts to protect rangeland.”

APHIS has the authority to implement Section 417 of the PPA through the Rangeland Grasshopper 

and Mormon Cricket Suppression Program. The priorities of the APHIS program are:

• to conduct surveys for grasshopper and Mormon cricket 

populations on rangelands in the western United States,

• to provide technical assistance on grasshopper management to

land owners/managers, and

• subject to the availability of funds, to suppress grasshoppers and

Mormon crickets on rangeland when direct intervention is requested 

by the land owner/manager.

Additional information regarding technical assistance and other aspects of the program can be 

obtained from the USDA Agricultural Research Service site at

http://www.sidney.ars.usda.gov/grasshopper/index.htm.

On September 16, 2016, APHIS and the Bureau of Indian Affairs (BIA) signed a Memorandum of 

Understanding (MOU) detailing cooperative efforts between the two groups on suppression of 

grasshoppers on BIA managed lands. This MOU clarifies that APHIS will prepare and issue to the public, 

site-specific environmental documents that evaluate potential impacts associated with the proposed 

measures to suppress economically damaging grasshopper populations. The MOU also states that these 

documents will be prepared under the APHIS NEPA implementing procedures with cooperation and 

input from the BIA.

The MOU further states that the responsible BIA official will request in writing the inclusion of 

appropriate lands in the APHIS suppression project when treatment on BIA land is necessary. The BIA 

must also approve a Pesticide Use Proposal for APHIS to treat infestations. According to the provisions 

of the MOU, APHIS can begin treatments after APHIS issues an appropriate decision document and 

BIA approves the Pesticide Use Proposal.

On November 6, 2019, APHIS and the Forest Service (FS) signed a Memorandum of Understanding 

(MOU) detailing cooperative efforts between the two groups on suppression of grasshoppers on FS 

managed lands (Document #19-8100-0573-MU, November 6, 2019). This MOU clarifies that APHIS 

will prepare and issue to the public, site-specific environmental documents that evaluate potential 

impacts associated with the proposed measures to suppress economically damaging grasshopper 

populations. The MOU also states that these documents will be prepared under the APHIS NEPA 

implementing procedures with cooperation and input from the FS.

The MOU further states that the responsible FS official will request in writing the inclusion of 

appropriate lands in the APHIS suppression project when treatment on FS land is necessary. The FS 

must also approve a Pesticide Use Proposal for APHIS to treat infestations. According to the provisions 

of the MOU, APHIS can begin treatments after APHIS issues an appropriate decision document and FS 

approves the Pesticide Use Proposal.
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On October 15, 2015, APHIS and the Bureau of Land Management (BLM) signed a Memorandum of 

Understanding (MOU) detailing cooperative efforts between the two groups on suppression of 

grasshoppers on BLM managed lands (Document #15-8100-0870-MU, October 15, 2015). This MOU 

clarifies that APHIS will prepare and issue to the public, site-specific environmental documents that 

evaluate potential impacts associated with the proposed measures to suppress economically damaging 

grasshopper populations. The MOU also states that these documents will be prepared under the APHIS 

NEPA implementing procedures with cooperation and input from the BLM.

The MOU further states that the responsible BLM official will request in writing the inclusion of 

appropriate lands in the APHIS suppression project when treatment on BLM land is necessary. The 

BLM must also approve a Pesticide Use Proposal for APHIS to treat infestations. According to the 

provisions of the MOU, APHIS can begin treatments after APHIS issues an appropriate decision 

document and BLM approves the Pesticide Use Proposal.

C. About This Process

The EA process for grasshopper management is complicated by the fact that there is very little time 

between requests for treatment and the need for APHIS to take action with respect to those requests. 

Surveys help to determine general areas, among the scores of millions of acres that potentially could be 

affected, where grasshopper infestations may occur in the spring of the following year. There is 

considerable uncertainty, however, in the forecasts, so that examining specific treatment areas for 

analysis under NEPA is not possible. At the same time, the program strives to alert the public in a timely 

manner to its more concrete treatment plans and avoid or minimize harm to the environment in 

implementing those plans.

The current EIS provides a solid analytical and regulatory foundation; however, it may not be enough to 

satisfy NEPA completely for actual treatment proposals. The program typically prepares a Draft EA 

tiered to the current EIS for each of the 17 Western States, or portion of a state, that may receive a 

request for treatment. The Draft EA analyzes aspects of environmental quality that could be affected by 

treatments in the area where grasshopper outbreaks are anticipated. The Draft EA will be made available 

to the public for a 30-day comment period. When the program receives a treatment request and 

determines that treatment is necessary, the specific site within the state will be evaluated to determine if 

environmental issues were not thoroughly evaluated in the Draft EA. If all environmental issues were 

covered in the Draft EA, the program will prepare a Final EA and Finding of No Significant Impact 

(FONSI) and send copies of those documents to any parties that submitted comments on the Draft EA 

and other appropriate stakeholders. To allow the program to respond to requests in a timely manner the 

Final EA and FONSI will then be posted to the APHIS website and the program will publish a notice of 

availability in the same manner used to advertise the availability of the Draft EA. 

II. Alternatives

To engage in comprehensive NEPA risk analysis APHIS must frame potential agency decisions into 

distinct alternative actions. These program alternatives are then evaluated to determine the significance 

of environmental effects. The 2002 EIS presented three alternatives: (A) No Action; (B) Insecticide 

Applications at Conventional Rates and Complete Area Coverage; and (C) Reduced Agent Area 

Treatments (RAATs), and their potential impacts were described and analyzed in detail. The 2019 EIS 

was tiered to, and updated the 2002 EIS. Therefore the 2019 EIS considered the environmental 

background or ‘No Action’ alternative of maintaining the program that was described in the 2002 EIS 

and Record of Decision. The 2019 EIS also considered an alternative where APHIS would not fund or 

participate in grasshopper suppression programs. The preferred alternative of the 2019 EIS allowed 

APHIS to update the program with new information and technologies that were not analyzed in the 2002 
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EIS. Copies of the complete 2002 and 2019 EIS documents are available for review at 3640 East Wier 

Ave., Phoenix, Arizona 85040. The Final Human Health and Ecological Risk Assessments for program 

pesticides are also available. These documents are also available at the Rangeland Grasshopper and 

Mormon Cricket Program web site, http://www.aphis.usda.gov/plant-health/grasshopper. 

All insecticides used by APHIS for grasshopper suppression are used in accordance with applicable 

product label instructions and restrictions. Representative product specimen labels can be accessed at the 

Crop Data Management Systems, Inc. web site at www.cdms.net/manuf/manuf.asp. Labels for actual 

products used in suppression programs will vary, depending on supply issues. All insecticide treatments 

conducted by APHIS will be implemented in accordance with APHIS’ treatment guidelines, included as 

Appendix 1 to this EA. APHIS supports the use of IPM to prevent grasshopper outbreaks on or near 

Federal lands. These actions are and should continue to be considered by agencies as part of proper land 

management. APHIS treatments are a component of the IPM strategies that may be employed by Federal 

land management agencies. APHIS also adheres to any restrictions proposed Federal land management 

agencies that may be a part of their IPM strategies. 

This EA analyzes the significance of environmental effects that could result from the alternatives

described below. These alternatives differ from those described in the 2019 EIS because grasshopper 

treatments are not likely to occur in most of Arizona and therefore the environmental baseline should 

describe a no treatment scenario.

A. No Action Alternative

Under Alternative A, the No Action alternative, APHIS would not fund or participate in any program to 

suppress grasshopper infestations within Arizona. Under this alternative, APHIS may opt to provide 

limited technical assistance, but any suppression program would be implemented by a Federal land 

management agency, a State agriculture department, a local government, or a private group or 

individual.

B. Insecticide Applications at Conventional Rates or Reduced Agent Area Treatments 

with Adaptive Management Strategy (Preferred Alternative)

Under Alternative B, the Preferred Alternative, APHIS would manage a grasshopper treatment program 

using techniques and tools discussed hereafter to suppress outbreaks. The insecticides available for use 

by APHIS include the U.S. Environmental Protection Agency (USEPA) registered chemicals carbaryl, 

diflubenzuron. These chemicals have varied modes of action: carbaryl work by inhibiting 

acetylcholinesterase (enzymes involved in nerve impulses); diflubenzuron is a chitin inhibitor; and 

APHIS would make a single application per year to a treatment area, and could apply insecticide at an 

APHIS rate conventionally used for grasshopper suppression treatments, or more typically as reduced 

agent area treatments (RAATs). APHIS selects which insecticides and rates are appropriate for 

suppression of a grasshopper outbreak based on several biological, logistical, environmental, and 

economical criteria. The identification of grasshopper species and their life stage largely determines the 

choice of insecticides used among those available to the program. RAATs are the most common 

application method for all program insecticides, and only rarely do rangeland pest conditions warrant 

full coverage and higher rates.

Preferred Alternative: Reduced Agent-Area Treatment (RAAT) approach as described in the literature, 

(Lockwood et al. 1999) involves applying low rates of insecticides in intermittent swaths of treated and 

untreated swaths, to control grasshopper infestations in an effort to achieve a more economically and 

environmentally sound pest management strategy compared to traditional blanket applications at high 

rates. A RAAT’s approach is an IPM strategy that takes advantage of grasshopper movement and 
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conservation biological control to allow insecticides to be applied on rangeland at a reduced rate and to a 

reduced amount of area, while still sustaining acceptable control of the population.

The RAATs strategy is effective for grasshopper suppression because the insecticide controls 

grasshoppers within treated swaths while conserving grasshopper predators and parasites in swaths not 

directly treated (Norelius & Lockwood. 1999, Lockwood et al. 2002). RAATs can decrease the rate of 

insecticide applied by either using lower insecticide concentrations or decreasing the deposition of 

insecticide applied by alternating one or more treatment swaths. Both options are most often

incorporated simultaneously into RAATs. Either carbaryl or diflubenzuron, would be considered under 

this alternative at the following application rates:

• 8.0 fluid ounces (0.25 lb a.i.) of carbaryl ULV spray per acre;

• 10.0 pounds (0.20 lb a.i.) of 2 percent carbaryl bait per acre;

• 10.0 pounds (0.50 lb a.i.) of 5 percent carbaryl bait per acre;

• 0.75 fluid ounce (0.012 lb a.i.) of diflubenzuron per acre;

• 1.0 fluid ounce (0.016 lb a.i.) of diflubenzuron per acre

The width of the area not directly treated (the untreated swath) under the RAATs approach is not 

standardized, due to varying equipment throughout the 17 Western States. The proportion of land treated 

in a RAATs approach is a complex function of the rate of grasshopper movement, which is a function of 

developmental stage, population density, and weather (Narisu et al., 1999, 2000, Lockwood et al. 2001)

as well as the properties of the insecticide (insecticides with longer residuals allow wider spacing 

between treated swaths). Foster et al. (2000) left 20 to 50% of their study plots untreated, while 

Lockwood et al. (2000) left 20 to 67% of their treatment areas untreated. Currently the grasshopper 

program typically leaves 50% of a spray block untreated for ground applications where the swath width 

is between 20 and 45 feet. For aerial applications, the skipped swath width is typically no more 100 feet 

for carbaryl and 200 feet for diflubenzuron. The selection of insecticide and the use of an associated 

swath widths is site dependent. Rather than suppress grasshopper populations to the greatest extent 

possible, the goal of this alternative is to suppress grasshopper populations to a desired level.

Conventional rates and complete area coverage, is an approach that APHIS has used in the past but is 

currently uncommon. Under this alternative, carbaryl, or diflubenzuron would cover all treatable sites 

within the designated treatment block per label directions. The application rates under this alternative 

are as follows:

• 16.0 fluid ounces (0.50 pound active ingredient (lb a.i.)) of carbaryl spray per acre;

• 10.0 pounds (0.50 lb a.i.) of 5 percent carbaryl bait per acre;

• 2.0 fluid ounce of diflubenzuron per acre

The potential generalized environmental effects of the application of carbaryl and diflubenzuron under 

this alternative are discussed in detail in the 2019 EIS. A description of anticipated site-specific impacts 

from this alternative may be found in Part IV of this document.
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C. Experimental Treatments Alternative

APHIS-PPQ continues to refine its methods of grasshopper and Mormon cricket management in order to 

improve the abilities of the Rangeland Grasshopper and Mormon Cricket Suppression Program (herein 

referred to as the Program) to make it more economically feasible, and environmentally acceptable. 

These refinements can include reduced rates of currently used pesticides, improved formulations, 

development of more target-specific baits, development of biological pesticide suppression alternatives, 

and improvements to aerial (e.g., incorporating the use of Unmanned Aircraft Systems (UAS)) and 

ground application equipment. A division of APHIS-PPQ, Science and Technology’s (S&T) Phoenix 

Lab is located in Arizona and its Rangeland Grasshopper and Mormon Cricket Management Team 

(Rangeland Unit) conducts methods development and evaluations on behalf of the Program. The 

Rangeland Unit’s primary mission is to comply with Section 7717 of the Plant Protection Act and 

protect the health of rangelands (wildlife habitats and where domestic livestock graze) against 

economically damaging cyclical outbreaks of grasshoppers and Mormon crickets. The Rangeland Unit 

tests and develops more effective, economical, and less environmentally harmful management methods 

for the Program and its federal, state, tribal, and private stakeholders. 

To achieve this mission, experimental plots ranging in area from less than one foot to 640 acres are used 

and often replicated. The primary purpose of these experiments is to test and develop improved methods 

of management for grasshoppers and Mormon crickets. This often includes testing and refining pesticide 

and biopesticide formulations that may be incorporated into the Program. These investigations often 

occur in the summer (May-August) and the locations typically vary annually. The plots often include 

“no treatment” (or control) areas that are monitored to compare with treated areas. Some of these plots 

may be monitored for additional years to gather information on the effects of utilized pesticides on nontarget arthropods. Note that an Experimental Use Permit is not needed when testing non-labeled 

experimental pesticides if the use is limited to laboratory or greenhouse tests, or limited replicated field 

Trials involving 10 acres or less per pest for terrestrial tests.

Studies and experimental plots are typically located on large acreages of rangelands and the Rangeland 

Unit often works on private land with the permission of landowners. Locations of experimental trials 

will be made available to the appropriate agencies in order to ensure these activities are not conducted 

near sensitive species or habitats. Due to the small size of the experimental plots, no adverse effects to 

the environment, including protected species and their critical habitats, are expected, and great care is 

taken to avoid sensitive areas of concern prior to initiating studies.

Methods Development Studies

Methods development studies may use planes and all-terrain vehicles (ATVs) to apply labeled pesticides 

using conventional applications and the Reduced Agent Area Treatments (RAATs) methodology. The 

experiments may include the use of an ultra-low volume sprayer system for applying biopesticides (such 

as native fungal pathogens). Mixtures of native pathogens and low doses of pesticides may be conducted 

to determine if these multiple stressor combinations enhance mortality. Aircraft will be operated by 

Federal Aviation Administration-licensed pilots with an aerial pesticide applicator’s permit. 

Rangeland Unit often uses one square foot micro plots covered by various types of cages depending on 

the study type and species used. These types of study plots are preferred for Mormon cricket treatments 

and those involving non-labeled experimental pesticides or biopesticides. Our most common application 

method for micro plots is simulating aerial applications via the Field Aerial Application Spray 

Simulation Tower Technique (FAASSTT). This system consists of a large tube enclosed on all sides 

except for the bottom, so micro plot treatments can be accurately applied to only the intended treatment 
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target. Treatments are applied with the FAASSTT in micro doses via a syringe and airbrush apparatus 

mounted in the top.

Rangeland Unit is also investigating the potential use of Unmanned Aerial Systems (UAS) for a number 

of purposes related to grasshopper and Mormon cricket detection and treatment. UAS will be operated 

by FAA-licensed pilots with an aerial pesticide applicator’s permit.

Pesticides and Biopesticides Used in Studies

Pesticides likely to be involved in studies currently include: 

1) Liquids: diflubenzuron (Dimilin 2L and generics: currently Unforgiven and Cavalier 2L) and 

chlorantraniliprole (Prevathon). Program standard application rates are: diflubenzuron - 1.0 fl. oz./acre 

in a total volume of 31 fl. oz./acre; chlorantraniliprole - 2.0 fl. oz./acre (RAATs) or 4.0 fl. oz./acre 

(conventional coverage), both in a total volume of 32 fl. oz./acre. Experimental rates often vary, but the 

doses are lower than standard Program rates unless otherwise noted. 

2) Baits: carbaryl. Program standard application rates: 2% bait at 10 lbs. /acre (2 lbs. AI/acre) or 5% bait 

at 4 lbs. /acre (2 lbs. AI/acre). 

3) LinOilEx (Formulation 103), a proprietary combination of easily available natural oils and some 

commonly encountered household products, created by Manfred Hartbauer, University of Graz, Austria. 

Note that LinOilEx (Formulation 103) is experimental; for more information, see “Potential Impacts of 

LinOilEx Applications” in the section “Information on Experimental Treatments.”

Biopesticides likely to be involved in studies currently include: 

1) Metarhizium robertsii (isolate DWR2009), a native fungal pathogen. Note that Metarhizium robertsii

(isolate DWR2009) is experimental; for more information, see “Potential Impacts of Metarhizium 

robertsii Applications” in the section “Information on Experimental Treatments.”

2) Beauveria bassiana GHA, a native fungal pathogen sold commercially and registered for use across 

the U.S.

At this time, we are unsure where in the 17 states we will be doing most of the following proposed 

experimental field studies. The final location decision is dependent upon grasshopper and/or Mormon 

cricket population densities, and availability of suitable sites, but we plan to most likely work in 

Arizona, Idaho, New Mexico, Oregon, Montana, or Washington.

Study 1: Evaluate efficacy of a UAS-mounted bait spreader applying 2% carbaryl bait at 5 lbs/acre. 

This study plans to use replicated 40 acre plots (320 acres total) on Colville Confederated Tribes land in 

Washington sometime in May/June, but is contingent upon a population of sufficient size. Mortality will 

be then be observed for a duration of time to determine efficacy.

Study 2: Evaluate persistence of the experimental biopesticide DWR2009 in bait form by coating wheat 

bran with the pathogen. A species of local abundance will be placed into replicated microplot cages and 

fed the baits by hand. Mortality and sporulation will be then be observed for a duration of time to

determine persistence in both the field and lab.

Study 3: Evaluate efficacy of the experimental biopesticide DWR2009 in bait form by coating wheat 

bran with the pathogen. A species of local abundance will be placed into replicated microplot cages and 
12

fed the baits by hand. Mortality and sporulation will be then be observed for a duration of time to 

determine efficacy in both the field and lab. 

Study 4: A stressor study to evaluate efficacy of the experimental biopesticide DWR2009 in liquid form 

when combined with Dimilin 2L. The FAASSTT will be utilized to apply varying dose levels of Dimilin 

2L (below label rates) in order to compare efficacy, starting at the rate of 1.0 fl. oz. /acre. Replicated 

microplots will be treated and then a species of local abundance will be placed into each cage. Mortality 

will be then be observed for a duration of time to determine efficacy.

Study 5: Evaluate efficacy of the experimental biopesticide DWR2009 in liquid and bait form (by 

coating wheat bran with the pathogen) using ultra-ultra low volume RAATs (involves a timing device 

and ULV nozzles) and a 10 acre plot. ATV-mounted liquid and bait spreaders will be utilized to apply 

DWR2009. Specimens will be periodically collected to observe mortality and sporulation for a duration 

of time to determine efficacy.

Study 6: Evaluate efficacy of the experimental, non-traditional pesticide LinOilEx (Formulation 103). A 

micro-FAASSTT (airbrush system mounted on a 5 gal bucket) will be utilized to apply varying dose 

levels in order to compare efficacy, starting at the base rate of 6.64 ml/cage. A species of local 

abundance will be placed into replicated microplot cages and sprayed directly. Mortality will be then be 

observed for a duration of time to determine efficacy.

III. Affected Environment

A. Description of Affected Environment

The proposed suppression program could potentially encompass acreage on rangeland in Coconino and 

Mohave County on the Hualapai Indian Reservation (appendix 4), in locations on the San Carlos Apache 

Reservation (appendix 5). The proposed treatment areas are identified as follows; rangeland in all tribal 

grazing allotments north of US 70, (the northern boundary made by the Salt and Black River and 

tributaries will be excluded from treatments and buffered by 1 mile from the canyon rim of the river), 

including Anchor -7, Ash Creek, R-100, Slaughter, POP, IDT and the portion of Tonto north of US 70. 

Antelope Flat area will exclude Cottonwood Canyon to the southeast from treatment area with a .5 

mile buffer along the canyon extending back to US 70. Ash Flat will exclude Bonita Creek from Bonita 

Springs downstream with a protective buffer being applied 1 mile upstream from Bonita Springs. Big 

Prairie area will exclude all forested areas and will only include rangeland areas. The vegetative

communities are; semiarid grasslands; Plains & Great Basin Grasslands; Great Basin Conifer woodland; 

Interior Chaparral covered in this area. Soil types include basalt and basalt flows, weakly consolidated 

sandstone and siltstone, unconsolidated alluvial sand, silt, and some gravel.

The proposed suppression program could potentially encompass acreage in locations on the Coronado 

National Forest within Winchester Mountains (appendix 6).

Elevations range from approximately 3,500 to over 6,000 feet. Potential treatment sites are within 

watersheds which drain into tributaries of the Gila river; Bonita Creek, Hackberry Creek, Hackberry 

Draw, Cottonwood Canyon Salt Creek, and San Carlos River. Potential treatment sites are also within 

watersheds which drain into the Salt River; Ash Creek and Black River. There are stock tanks in the 

potential treatment area. All potential treatment areas fall within the Arizona Interior Chaparral biome 

(Brown, 1994), grassland representative species of this biome include:

Plants: Emory oak (Quercus emoryi), alligator bark juniper (Juniperus deppeana), pinyon pine (Pinus 

edulis), gray oak (Quercus grisea), canyon live oak (Quercus chrysolepis), Arizona oak (Quercus 

arizonica), western chokecherry (Prunus virginiana), shrub live-oak (Quercus turbinella), ceanothus 
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(Ceanothus greggii), crucifixion thorn (Canotia holocantha), penstemon (Penstemon spp.), desert 

verbena (Verbena wrightii), Wright buckwheat (Eriogonum wrightii), narrowleaf yerbasanta

(Eriodictyon angustifolium), sideoats grama (Bouteloua curtipendula), cane bluestem (Bothriochloa 

barbinodis), plains lovegrass (Eragrostis intermedia), Black grama (Bouteloua eriopoda), Blue grama, 

(Bouteloua gracilis) Hairy grama, (Bouteloua hirsuta) Rothrock’s grama, (Bouteloua rothrockii), 

Fendler three-awn (Aristida spp.), agave (Agave parryi), beargrass (Nolina microcarpa), sotol 

(Dasylirion wheeleri), banana yucca (Yucca baccata), , squirreltail, (Elymus elymoides), Arizona 

cottontop, (Digitaria californica), Green sprangletop (Leptochloa dubia), Junegrass, (Koeleria spp.), 

Western wheatgrass (Pascopyrum smithii), Tobosagrass, (Pleuraphis mutica), Vine Mesquite, (Panicum 

obtusum), curly-mesquite (Hilaria belangeri ), Cholla (Opuntia spp.), Prickly Pear (Opuntia spp.),

Mammals: cliff chipmunk (Eutamias dorsalis), white-throated woodrat (Neotoma albigula), mule deer 

(Odocoileus hemionus), brush mouse (Peromyscus boylei), rock mouse (P. difficilis), white- footed 

mouse (P. leucopus), eastern cottontail (Sylvilagus floridanus holzeri), pronghorn antelope (Antilocapra 

americana), elk (Cervus elaphus) javalina (Pecari tajacu), jackrabbit (Lepus spp.), coyote (Canis 

latran), White-tailed deer (Odocoileus virginianus).

Birds: rufous-crowned sparrow (Aimophila ruficeps), scrub jay (Aphelocoma coerulescens), canyon 

wren (Catherpes mexicanus), rufous-sided towhee (Pipilo erythrophthalmus), brown towhee (P. fuscus), 

bushtit (Psaltriparus minimus), black-chinned sparrow (Spizella atrogularis), crissal thrasher 

(Toxostoma dorsale), burrowing owl (Athene cunicularia).

Amphibians and reptiles: glossy snake (Arizona elegans), Arizona alligator lizard(Gerrhonotus kingi), 

night snake (Hypsiglena torquata), Sonoran mountain kingsnake (Lampropeltis pyromelana), 

southwestern blind snake (Leptotyphlops humilis), Sonora whipsnake (Masticophis bilineatus), desert 

striped whipsnake (M. taeniatus), western fence lizard (Scleroporus occidentalis), eastern fence lizard 

(S. undulates), western blackhead snake (Tantilla planiceps), Sonoran lyre snake (Trimorphodon 

biscutatus lambda), Texas lyre snake (T. b. vilkinsoni), side-blotched lizard (Uta stansburiana), Arizona 

night lizard (Zantusia arizonae), Western Diamond-backed Rattlesnake (Crotalus atrox), Black-tailed 

Rattlesnake (Crotalus molossus), Arizona Black Rattlesnake (Crotalus cerberus)

B. Site-Specific Considerations

1. Human Health

The 2019 EIS contains detailed hazard, exposure, and risk analyses for the chemicals available to 

APHIS. APHIS has incorporated by reference the analysis from the EIS and the associated risk 

assessments of pesticides which are mentioned this EA. These documents are titled, The Final Human 

Health and Ecological Risk Assessments (USDA, APHIS 2018a, 2018b, 2018c, 2018d) for program 

pesticides which are available at the following website, http://www.aphis.usda.gov/planthealth/grasshopper.

Impacts to workers and the general public were analyzed for all possible routes of exposure (dermal, 

oral, inhalation) under a range of conditions designed to overestimate risk. The operational procedures 

and spraying conditions examined in those analyses conform to those expected for operations. The

following discussion summarizes the hazards, potential exposure, and risk to workers and the general

public for operations within these potential proposed treatment areas detailed in this EA. The operational 

procedures identified in Appendix 1 would be required in all cases and further mitigation measures are 

identified in this section, as appropriate.
14

The suppression program would be conducted on federally managed rangelands. No treatments will

occur over congested or residential areas, recreation areas, and schools. The nearest residential or 

populated area to potential treatment areas are at least 6 miles away. Refer to the Operational 

Procedures, Specific Procedures for Aerial and Ground Applications in Appendix 1 for further 

information.

Groundwater wells are a major source of domestic water supplies. Groundwater and surface water 

are the major rural and livestock water sources. No impact is anticipated. Strict adherence to label 

requirements and the USDA treatment guidelines (appendix 1) will be followed in regard to 

treatments bordering open surface waters.

2. Nontarget Species

 Threatened & Endangered Species and Sensitive Species of Concern

The area assessed by this EA includes a variety of organisms i.e.; terrestrial vertebrates and 

invertebrates, migratory birds, biocontrol agents, pollinators, aquatic organisms, plants (both native and 

introduced), etc. APHIS will employ measures, such as buffer zones, to protect these species and their 

habitat. APHIS will also consult with local agency officials to determine appropriate protective 

measures.

Federally Listed Threatened and Endangered Species:

MAMMALS

Endangered Mexican gray wolf, Canis lupus baileyi - Endangered

Ocelot, Leopardus pardalis - Endangered

Black-footed ferret, Mustela nigripes -Endangered

BIRDS

Mexican spotted owl, Strix occidentalis lucida - Threatened 

Southwestern willow flycatcher, Empidonax traillii extimus -Endangered 

Western yellow-billed cuckoo, Coccyzus americanus – Threatened 

California condor, Gymnogyps californianus - Endangered

Yuma Ridgway’s rail, Rallus obsoletus yumanensis – Endangered

FISH

Apache trout, Oncorhynchus apache - Threatened 

Desert pupfish, Cyprinodon macularius - Endangered 

Gila chub, Gila intermedia - Endangered

Gila topminnow, Poeciliopsis occidentalis occidentalis - Endangered 

Loach minnow, Tiaroga cobitis - Threatened
15

Spikedace, Meda fulgida - Threatened 

Humpback chub, Gila cypha

Razorback sucker, Xyrauchen texanus – Endangered

Woundfin Plagopterus argentissimus – Endangered

AMPHIBIANS

Chiricahua leopard frog, Rana chiricahuensis - Threatened

PLANTS

Arizona cliffrose, Purshia subintegra - Endangered

Arizona hedgehog cactus, Echinocereus triglochidiatus var. arizonicus - Endangered

REPTILES

Northern Mexican gartersnake, Thamnophis eques megalops - Threatened 

Narrow-headed gartersnake, Thamnophis rufipunctatus - Threatened

Sensitive Species of Concern:

Sonoran Desert tortoise, Gopherus morafkai – Candidate 

Headwater chub, Gila nigra - Candidate

Roundtail chub, Gila robusta – Candidate

 

 Bald and Golden Eagle Protection Act (BGEPA)

The Eagle Act (16 U.S.C. 668-668c), enacted in 1940, and amended several times since then, prohibits 

anyone, without a permit issued by the Secretary of the Interior, from “taking” bald eagles, including 

their parts, nests, or eggs. The Act provides criminal and civil penalties for persons who “take, possess,

sell, purchase, barter, offer to sell, purchase or barter, transport, export or import, at any time or any

manner, any bald eagle ... [or any golden eagle], alive or dead, or any part, nest, or egg thereof.” The Act

defines “take” as “pursue, shoot, shoot at, poison, wound, kill, capture, trap, collect, molest or disturb.” 

“Disturb’’ means: "Disturb means to agitate or bother a bald or golden eagle to a degree that causes, or 

is likely to cause, based on the best scientific information available, 1) injury to an eagle, 2) a decrease 

in its productivity, by substantially interfering with normal breeding, feeding, or sheltering behavior, or 

3) nest abandonment, by substantially interfering with normal breeding, feeding, or sheltering behavior." 

In addition to immediate impacts, this definition also covers impacts that result from human- induced

alterations initiated around a previously used nest site during a time when eagles are not present, if, upon 

the eagles return, such alterations agitate or bother an eagle to a degree that injures an eagle or 

substantially interferes with normal breeding, feeding, or sheltering habits and causes, or is likely to 

cause, a loss of productivity or nest abandonment.

As listed in the National Bald Eagle Management Guidelines (USFWS, May 2007) and adapting 

recommendations from (Driscoll et al. 2006) the following mitigation measures will be followed.

Category G Helicopters and fixed-wing aircraft. Except for authorized biologists trained in survey 

techniques, avoid operating aircraft within 2,000 feet of the nest during the breeding season, except 

where eagles have demonstrated tolerance for such activity. In addition, Category A (Agriculture) and 

Category D (Off Road Vehicle Use) both provide the same guidance for use of ATV's or trucks: No 

buffer is necessary around nest sites outside the breeding season. During the breeding season, do not 
16

operate off-road vehicles within 1,000 feet of the nest. In open areas, where there is increased visibility

and exposure to noise, this distance should be extended to 1,000 feet.

 Representative wildlife and plant spp.

See Table 1 for list of representative wildlife, and plant spp.

Under the no action alternative, destruction of grasses and forbs by grasshoppers could cause localized 

disruption of food and cover for a number of wildlife species. Under chemical control there is a 

possibility of indirect effects on local wildlife populations, particularly insectivorous birds that depend 

on a readily available supply of insects, including grasshoppers, for their own food supply and for their 

young. We have found no valid data which suggests that (absent a spill) any species other than certain 

mice would be subjected to a dosage in excess of 1/5 of the LD50 for carbaryl (Pg. B-37 GH EIS.) 

Therefore, it is not apparent that any fatalities would be likely to occur as a result of carbaryl 

intoxication.

Malathion and carbaryl have been shown to reduce brain cholinesterase (ChE) (an enzyme important in 

nerve cell transmissions) levels in birds. Effects of ChE inhibition are not fully understood but could 

cause inability to gather food, escape predation, or care for young.

In any given treatment season, only a fraction (less than 1 percent) of the total rangeland in a region is 

likely to be sprayed for grasshopper control. For species that are wide spread and numerous lowered 

survival and lowered reproductive success in a small portion of their habitat would not constitute a 

significant threat to the population.

The wildlife risk assessment in APHIS FEIS 2002 estimated wildlife doses of Malathion and carbaryl to 

representative rangeland species and compared them with toxicity reference levels. No dose of 

Malathion will approach or exceed the reference species LD50. Some individual animals may be at risk 

of fatality or behavioral alterations that make them more susceptible to predation resulting from ChE 

level changes in Malathion spraying for grasshopper control. However, most individual animals would 

not be seriously affected.

Carbaryl also poses a low risk to wildlife, with few fatalities likely to occur and a low risk of behavioral 

anomalies caused by cholinesterase depression. There is some chance of adverse effects on bird 

reproduction through the use of any of these chemicals or diesel oil through direct toxicity to developing 

embryos in birds' eggs.

Some species of herbivorous mammals and birds may consume wheat bran bait after it has been applied

to grasshopper-infested areas. Carbaryl is moderately toxic to mammals and slightly toxic to birds. We 

have found no valid data which suggests that (absent a spill) any species other than certain mice would 

be subjected to a dosage in excess of 1/5 of the LD50 for carbaryl (Pg. B-37 GH EIS.) Therefore, it is 

not apparent that any fatalities would be likely to occur as a result of carbaryl intoxication. Additionally, 

we note that carbaryl 5% bait is labeled at 3 lbs. /1000ft2 in poultry houses when poultry are present.

(http://www.cdms.net/manuf/)

Chitin or chitin-like substances are not as important to terrestrial mammals, birds, and other vertebrates 

as chitin is to insects; therefore, the chitin inhibiting properties of diflubenzuron applications under the 

conditions of Alternative 2 such as reductions in the food base for insectivorous wildlife species, 

especially birds. As stated above, diflubenzuron is practically nontoxic to birds, including those birds 

that ingest moribund grasshoppers resulting from diflubenzuron applications, as described in Alternative 

2.
17

While immature grasshoppers and other immature insects can be reduced up to 98 percent in area 

covered with diflubenzuron, some grasshoppers and other insects remain in the treatment area. Although 

the density of grasshoppers and other insects may be low, it is most likely sufficient to sustain birds and 

other insectivores until insect populations recover. Those rangeland birds that feed primarily on

grasshoppers may switch to other diet items. However, in some areas the reduced number of invertebrates 

necessary for bird survival and development may result in birds having less available food. In these 

cases, birds will either have less than optimal diets or travel to untreated areas for suitable prey items, 

causing a greater foraging effort and a possible increased susceptibility to predation. It also should be 

noted that suppressing grasshopper populations conserves rangeland vegetation that often is important 

habitat to rangeland wildlife. Habitat loss is frequently the most important factor leading to the decline of

a species, and reducing grasshopper densities can be an aid in reducing habitat loss.

APHIS is the lead agency in Arizona regarding biological control for invasive weeds. All biocontrol 

programs are coordinated between APHIS and Federal, Tribal, State agencies and Weed Management 

Districts and City Municipalities. APHIS has GIS data for all Biological Control programs throughout 

Arizona. There has been no overlap between biocontrol programs and grasshopper treatments. If this 

does become the case in the future, the grasshopper program would eliminate questionable acreage from 

the treatment area.

3. Socioeconomic Issues

Livestock grazing and hunting are the main uses of the potential treatment area. These grasslands 

provide forage for cattle and wildlife. Farming, forestry occupations, agriculture, fishing and hunting, 

and mining provide 10.6% of the employment on San Carlos Apache Reservation (U.S. Bureau of the 

Census, Census 2000).

The total population of the Hualapai Reservation is about 1,621 of whom 1,353 are tribal members (2000 

U.S. Census). The principal economic activities are tourism, cattle ranching, and arts and crafts. The 

Hualapai Reservation is rich in hunting, fishing, and river rafting opportunities. The tribe sells guided 

big-game hunting permits for desert bighorn sheep, trophy elk, antelope, and mountain lion.

The possible treatment areas are subject to reoccurring drought. A combination of drought and 

grasshopper damage causes economic stress to landowners and permittees. The control of grasshoppers

in this area would have beneficial economic impacts to local land owners. The forage not utilized by

grasshoppers will be available for livestock consumption, and harvesting. This will allow greater 

livestock grazing, decreased needs for supplemental feed, and increased monetary returns.

4. Cultural Resources and Events

To ensure that historical or cultural sites, monuments, buildings or artifacts of special concern are not 

adversely affected by program treatments, APHIS will confer with BIA, or other appropriate land 

management agencies on a local level to protect these areas of special concern. APHIS will also confer

with the appropriate Tribal Authority and with the BIA office at a local level to ensure that the timing and

location of planned program treatments do not coincide or conflict with cultural events or observances, on 

Tribal and/or allotted lands.
18

5. Special Considerations for Certain Populations

a) Executive Order No. 12898, Federal Actions to Address Environmental Justice in Minority 

Populations and Low-Income Populations

Executive Order (E.O.) 12898, Federal Actions To Address Environmental Justice in Minority 

Populations and Low-Income Populations, was signed by President Clinton on February 11, 1994 (59 

Federal Register (FR) 7269). This E.O. requires each Federal agency to make achieving environmental 

justice part of its mission by identifying and addressing, as appropriate, disproportionately high and 

adverse human health or environmental effects of its programs, policies, and activities on minority 

populations and low-income populations. Consistent with this E.O., APHIS will consider the potential 

for disproportionately high and adverse human health or environmental effects on minority populations 

and low-income populations for any of its actions related to grasshopper suppression programs. 

The San Carlos Apache Reservation has a population of 9,385, with 96.6% of the population being 

American Indian. The remaining population consists of 3.9% white, 0.2% African American, 0.3% Asian, 

and 0.1% Native Hawaiian or Other Pacific Islander, 0.7% some other race. The median household 

income is $16,894 per year, with a per capita income of $5,200. Over 50% of the population lives in 

poverty status (U.S. Census Bureau 2000).

The total population of the Hualapai Reservation is about 1,621 of whom 1,353 are tribal members (2000

U.S. Census). There are slightly more females (52.8%) than males (47.2%) within the Hualapai Tribe. 

The percentage of males in the Hualapai Tribe was lower than either the State (49.7%) or the County 

(50.0%), while females (52.8%) comprised a larger proportion of the population among the Hualapai

that either the State (50.3%) or the County (50.0%). The majority of Hualapai tribal members identify 

themselves as American Indian or Alaska Native alone (95%), while the remaining 5 percent are split 

between white alone, some other race alone, and multi-race persons. Poverty rates on the Hualapai Tribe

(41%) are more than twice as high as the State (15%) and the County (16%). More than half (53%) of all

children under 18 years of age are considered to be living in poverty, while one-third (32%) of tribal 

members between 18 and 64 also live in poverty. One-fourth (26%) of tribal members over 65 years of

age live in poverty, three times the State (8%) and the County (7%) rates (U.S. Census Bureau 2000).

b) Executive Order No. 13045, Protection of Children from Environmental Health Risks and 

Safety Risks

The increased scientific knowledge about the environmental health risks and safety risks associated with 

hazardous substance exposures to children and recognition of these issues in Congress and Federal 

agencies brought about legislation and other requirements to protect the health and safety of children. 

On April 21, 1997, President Clinton signed E.O. 13045, Protection of Children From Environmental 

Health Risks and Safety Risks (62 FR 19885). This E.O. requires each Federal agency, consistent with 

its mission, to identify and assess environmental health risks and safety risks that may disproportionately 

affect children and to ensure that its policies, programs, activities, and standards address those risks. 

APHIS has developed agency guidance for its programs to follow to ensure the protection of children 

(USDA, APHIS, 1999). 

Approximately 47% of the population on the San Carlos Apache Reservation is under 19 years of age 

(4,450 of 9,385) (U.S. Census Bureau 2000). Approximately 31% of the population on the Hualapai 

Reservation is under 17 years of age (418 of 1353) (U.S. Census Bureau 2000). The human health risk 

assessment for the 2002 EIS analyzed the effects of exposure to children from the three insecticides.

Based on review of the insecticides and their use in the grasshopper program, the assessment concluded

that the likelihood of children being exposed to insecticides is very slight and that no disproportionate 
19

adverse effects to children are anticipated over the negligible effects to the general populations.

Treatments are primarily conducted on open rangelands where children would not be expected to be 

present during treatment or enter should there be any restricted entry period after treatment.

IV. Environmental Consequences

Each alternative described in this EA potentially has adverse environmental effects. The general 

environmental impacts of each alternative are discussed in detail in the 2002 and 2019 EIS. The specific 

impacts of the alternatives are highly dependent upon the particular action and location of infestation. 

The principal concerns associated with the alternatives are: (1) the potential effects of insecticides on 

human health (including subpopulations that might be at increased risk); and (2) impacts of insecticides 

on non-target organisms (including threatened and endangered species). 

APHIS has written human health and ecological risk assessments (HHERAs) to assess the insecticides 

and use patterns that are specific to the program. The risk assessments provide an in-depth technical 

analysis of the potential impacts of each insecticide to human health; and non-target fish and wildlife 

along with its environmental fate in soil, air, and water. The assessments rely on data required by the 

USEPA for pesticide product registrations, as well as peer-reviewed and other published literature. The 

HHERAs are heavily referenced in this [Draft EA]. These Environmental Documents can be found at 

the following website: http://www.aphis.usda.gov/plant-health/grasshopper. 

A. Environmental Consequences of the Alternatives

Site-specific environmental consequences of the alternatives are discussed in this section.

1. No Action Alternative

Under this alternative, APHIS would not fund or participate in any program to suppress grasshoppers. If 

APHIS does not participate in any grasshopper suppression program, Federal land management 

agencies, State agriculture departments, local governments, private groups or individuals, may not 

effectively combat outbreaks in a coordinated effort. Without the technical assistance and coordination 

that APHIS provides during grasshopper outbreaks, the uncoordinated programs could use insecticides, 

including those labeled for rangeland use that APHIS considers too environmentally harsh. Multiple 

treatments and excessive amount of insecticide could be applied in efforts to suppress or even locally 

eradicate grasshopper populations. There are approximately 100 pesticide products were registered by 

USEPA for use on rangelands and against grasshoppers (Purdue University, 2018). It is not possible to 

accurately predict the environmental consequences of the No Action alternative because the type and 

amount of insecticides that could be used in this scenario are unknown. However, the environmental 

impacts could be much greater than under the APHIS led suppression program alternative due to lack of 

treatment knowledge or coordination among the groups.

The potential environmental impacts from the No Action alternative, where other agencies and land 

managers do not control outbreaks, stem primarily from grasshoppers consuming vast amounts of 

vegetation in rangelands and surrounding areas. Grasshoppers are general feeders, eating grasses and 

weeds first and often moving to cultivated crops. High grasshopper density of one or several species and 

the resulting defoliation may reach an economic threshold where the damage caused by grasshoppers 

exceeds the cost of controlling the grasshoppers. Researchers determined that during typical grasshopper 

infestation years, approximately 20% of forage rangeland is removed, valued at a dollar adjusted amount 

of $900 million. This value represents 32 to 63% of the total value of rangeland across the western states 

(Rashford et al., 2012). Other market and non-market values such as carbon sequestration, general 

ecosystem services, and recreational use may also be impacted by pest outbreaks in rangeland.
20

Vegetation damage during serious grasshopper outbreaks may be so severe that all grasses and forbs are 

destroyed; thus, plant growth is impaired for several years. Rare plants may be consumed during critical 

times of development such as seed production, and loss of important plant species, or seed production 

may lead to reduced diversity of rangeland habitats, potentially creating opportunities for the expansion 

of invasive and exotic weeds (Lockwood and Latchininsky, 2000). When grasshoppers consume plant 

cover, soil is more susceptible to the drying effects of the sun, making plant roots less capable of holding 

soil in place. Soil damage results in erosion and disruption of nutrient cycling, water infiltration, seed 

germination, and other ecological processes which are important components of rangeland ecosystems 

(Latchininsky et al., 2011).

When the density of grasshoppers reaching significantly high levels, grasshoppers begin to compete with 

livestock for food by reducing available forage (Wakeland and Shull, 1936; Belovsky, 2000; Pfadt, 

2002; Branson et al., 2006; Bradshaw et al., 2018). Ranchers could offset some of the costs by leasing 

rangeland in another area and relocating their livestock, finding other means to feed their animals by 

purchasing hay or grain, or selling their livestock. Ranchers could also incur economic losses from 

personal attempts to control grasshopper damage. Local communities could see adverse economic 

impacts to the entire area. Grasshoppers that infest rangeland could move to surrounding croplands. 

Farmers could incur economic losses from attempts to control chemically grasshopper populations or 

due to the loss of their crops. The general public could see an increase in the cost of meat, crops, and 

their byproducts.

2. Insecticide Applications at Conventional Rates or Reduced Agent Area Treatments 

with Adaptive Management Strategy

Under Alternative 2, APHIS would participate in grasshopper programs with the option of using one of 

the insecticides carbaryl or diflubenzuron depending upon the various factors related to the grasshopper 

outbreak and the site-specific characteristics. The use of an insecticide would typically occur at half the 

conventional application rates following the RAATs strategy. APHIS would apply a single treatment to

affected rangeland areas in an attempt to suppress grasshopper outbreak populations by a range of 35 to 

98 percent, depending upon the insecticide used. 

a) Carbaryl

Carbaryl is a member of the N-methyl carbamate class of insecticides, which affect the nervous system 

via cholinesterase inhibition. Inhibiting the enzyme acetylcholinesterase (AChE) causes nervous system 

signals to persist longer than normal. While these effects are desired in controlling insects, they can have 

undesirable impacts to non-target organisms that are exposed. The APHIS HHERA assessed available 

laboratory studies regarding the toxicity of carbaryl on fish and wildlife. In summary, the document 

indicates the chemical is highly toxic to insects, including native bees, honeybees, and aquatic insects; 

slightly to highly toxic to fish; highly to very highly toxic to most aquatic crustaceans, moderately toxic 

to mammals, minimally toxic to birds; moderately to highly toxic to several terrestrial arthropod 

predators; and slightly to highly toxic to larval amphibians (USDA APHIS, 2018a). 

The offsite movement and deposition of carbaryl after treatments is unlikely because it does not

significantly vaporize from the soil, water, or treated surfaces (Dobroski et al., 1985). Temperature, pH, 

light, oxygen, and the presence of microorganisms and organic material are factors that contribute to 

how quickly carbaryl will degrade in water. Hydrolysis, the breaking of a chemical bond with water, is 

the primary degradation pathway for carbaryl at pH 7 and above. In natural water, carbaryl is expected 

to degrade faster than in laboratory settings due to the presence of microorganisms. The half-lives of 

carbaryl in natural waters varied between 0.3 to 4.7 days (Stanley and Trial, 1980; Bonderenko et al., 

2004). Degradation in the latter study was temperature dependent with shorter half-lives at higher 

temperatures. Aerobic aquatic metabolism of carbaryl reported half-life ranged of 4.9 to 8.3 days 
21

compared to anaerobic (without oxygen) aquatic metabolism range of 15.3 to 72 days (Thomson and 

Strachan, 1981; USEPA, 2003). Carbaryl is not persistent in soil due to multiple degradation pathways 

including hydrolysis, photolysis, and microbial metabolism. Little transport of carbaryl through runoff 

or leaching to groundwater is expected due to the low water solubility, moderate sorption, and rapid 

degradation in soils. There are no reports of carbaryl detection in groundwater, and less than 1% of 

granule carbaryl applied to a sloping plot was detected in runoff (Caro et al., 1974).

Acute and chronic risks to mammals are expected to be low to moderate based on the available toxicity 

data and conservative assumptions that were used to evaluate risk. There is the potential for impacts to 

small mammal populations that rely on terrestrial invertebrates for food. However, based on the toxicity 

data for terrestrial plants, minimal risks of indirect effects are expected to mammals that rely on plant 

material for food. Carbaryl has a reported half-life on vegetation of three to ten days, suggesting 

mammal exposure would be short-term. Direct risks to mammals from carbaryl bait applications is 

expected to be minimal based on oral, dermal, and inhalation studies (USDA APHIS, 2018a).

A number of studies have reported no effects on bird populations in areas treated with carbaryl (Buckner 

et al., 1973; Richmond et al., 1979; McEwen et al., 1996). Some applications of formulated carbaryl 

were found to cause depressed AChE levels (Zinkl et al., 1977; Gramlich, 1979); however, the doses 

were twice those proposed for the full coverage application in the grasshopper program.

While sublethal effects have been noted in fish with depressed AChE, as well as some impacts to 

amphibians (i.e. days to metamorphosis) and aquatic invertebrates in the field due to carbaryl, the 

application rates and measured aquatic residues observed in these studies are well above values that 

would be expected from current program operations. Indirect risks to amphibian and fish species can 

occur through the loss of habitat or reduction in prey, yet data suggests that carbaryl risk to aquatic 

plants that may serve as habitat, or food, for fish and aquatic invertebrates is very low.

Product use restrictions appear on the USEPA-approved label and attempt to keep carbaryl out of 

waterways. Carbaryl must not be applied directly to water, or to areas where surface water is present 

(USEPA, 2012c). The USEPA-approved use rates and patterns and the additional mitigations imposed 

by the grasshopper program, such as using RAATs and application buffers, where applicable, further 

minimize aquatic exposure and risk.

The majority of rangeland plants require insect-mediated pollination. Native, solitary bee species are 

important pollinators on western rangeland (Tepedino, 1979). Potential negative effects of insecticides 

on pollinators are of concern because a decrease in their numbers has been associated with a decline in 

fruit and seed production of plants. Laboratory studies have indicated that bees are sensitive to carbaryl 

applications but the studies were at rates above those proposed in the program. The reduced rates of 

carbaryl used in the program and the implementation of application buffers should significantly reduce 

exposure of carbaryl applications to pollinators. In areas of direct application where impacts may occur, 

alternating swaths and reduced rates (i.e., RAATs) would reduce risk. Potential negative effects of 

grasshopper program insecticides on bee populations may also be mitigated by the more common use of 

carbaryl baits than the ULV spray formulation. Studies with carbaryl bran bait have found no sublethal 

effects on adults or larvae bees (Peach et al., 1994, 1995).

Carbaryl can cause cholinesterase inhibition (i.e., overstimulate the nervous system) in humans resulting 

in nausea, headaches, dizziness, anxiety, and mental confusion, as well as convulsions, coma, and 

respiratory depression at high levels of exposure (NIH, 2009a;Beauvais, 2014). USEPA classifies 

carbaryl as “likely to be carcinogenic to humans” based on vascular tumors in mice (USEPA, 2007, 

2015a, 2017a).
22

USEPA regulates the amount of pesticide residues that can remain in or on food or feed commodities as 

the result of a pesticide application. The agency does this by setting a tolerance, which is the maximum 

residue level of a pesticide, usually measured in parts per million (ppm), that can legally be present in 

food or feed. USEPA-registered carbaryl products used by the grasshopper program are labeled with 

rates and treatment intervals that are meant to protect livestock and keep chemical residues in cattle at 

acceptable levels (thereby protecting human health). While livestock and horses may graze on rangeland 

the same day that the land is sprayed, in order to keep tolerances to acceptable levels, carbaryl spray 

applications on rangeland are limited to half a pound active ingredient per acre per year (USEPA, 

2012c). The grasshopper program would treat at or below use rates that appear on the label, as well as 

follow all appropriate label mitigations, which would ensure residues are below the tolerance levels.

Adverse human health effects from the proposed program ULV applications of the carbaryl spray 

(Sevin® XLR Plus) and bait applications of the carbaryl 5% and 2% baits formulations to control 

grasshoppers are not expected based on low potential for human exposure to carbaryl and the favorable 

environmental fate and effects data. Technical grade (approximately 100% of the insecticide product is 

composed of the active ingredient) carbaryl exhibits moderate acute oral toxicity in rats, low acute 

dermal toxicity in rabbits, and very low acute inhalation toxicity in rats. Technical carbaryl is not a 

primary eye or skin irritant in rabbits and is not a dermal sensitization in guinea pig (USEPA, 2007). 

This data can be extrapolated and applied to humans revealing low health risks associated with carbaryl.

The Sevin® XLR Plus formulation, which contains a lower percent of the active ingredient than the 

technical grade formulation, is less toxic via the oral route, but is a mild irritant to eyes and skin. The 

proposed use of carbaryl as a ULV spray or a bait, use of RAATs, and adherence to label requirements, 

substantially reduces the potential for exposure to humans. The most likely exposed human populations 

are program workers. APHIS does not expect adverse health risks to workers based on low potential for 

exposure to carbaryl when applied according to label directions and use of personal protective 

equipment (PPE) (e.g., long-sleeved shirt and long pants, shoes plus socks, chemical-resistant gloves, 

and chemical-resistant apron) (USEPA, 2012c) during loading and applications. APHIS quantified the 

potential health risks associated with accidental worker exposure of carbaryl during mixing, loading, and 

applications. The quantitative risk evaluation results indicate no concerns for adverse health risk for 

program workers (http://www.aphis.usda.gov/plant-health/grasshopper).

Adherence to label requirements and additional program measures designed to reduce exposure to 

workers and the public (e.g., mitigations to protect water sources, mitigations to limit spray drift, and 

restricted-entry intervals) result in low health risk to all human population segments.

b) Diflubenzuron

Diflubenzuron is a restricted use pesticide (only certified applicators or persons under their direct 

supervision may make applications) registered with USEPA as an insect growth regulator. It specifically 

interferes with chitin synthesis, the formation of the insect’s exoskeleton. Larvae of affected insects are 

unable to molt properly. While this effect is desirable in controlling certain insects, it can have 

undesirable impacts to non-target organisms that are exposed.

USEPA considers diflubenzuron relatively non-persistent and immobile under normal use conditions 

and stable to hydrolysis and photolysis. The chemical is considered unlikely to contaminate ground 

water or surface water (USEPA, 1997). The vapor pressure of diflubenzuron is relatively low, as is the 

Henry’s Law Constant value, suggesting the chemical will not volatilize readily into the atmosphere 

from soil, plants or water. Therefore, exposure from volatilization is expected to be minimal. Due to its 

low solubility (0.2 mg/L) and preferential binding to organic matter, diflubenzuron seldom persists more 

than a few days in water (Schaefer and Dupras, 1977; Schaefer et al., 1980). Mobility and leachability of 

diflubenzuron in soils is low, and residues are usually not detectable after seven days (Eisler, 2000). 
23

Aerobic aquatic half-life data in water and sediment was reported as 26.0 days (USEPA, 1997). 

Diflubenzuron applied to foliage remains adsorbed to leaf surfaces for several weeks with little or no 

absorption or translocation from plant surfaces (Eisler, 1992, 2000). Diflubenzuron treatments are 

expected to have minimal effects on terrestrial plants. Both laboratory and field studies demonstrate no 

effects using diflubenzuron over a range of application rates, and the direct risk to terrestrial plants is 

expected to be minimal (USDA APHIS, 2018c).

Dimilin® 2L is labeled with rates and treatment intervals that are meant to protect livestock and keep 

residues in cattle at acceptable levels (thereby, protecting human health). Tolerances are set for the 

amount of diflubenzuron that is allowed in cattle fat (0.05 ppm) and meat (0.05 ppm) (40 CFR Parts 

180.377). The grasshopper program would treat at application rates indicated on product labels or lower, 

which should ensure approved residues levels. 

APHIS’ literature review found that on an acute basis, diflubenzuron is considered toxic to some aquatic 

invertebrates and practically non-toxic to adult honeybees. APHIS utilizes diflubenzuron at far-lower 

levels than allowed by the label, thereby minimizing risks to non-targets, such as bees. There have been 

several studies on diflubenzuron effects on bees, such as Schroeder et al., 1980 and insect growth 

regulator effects reviewed in Tasei, 2001, which support the idea that the diflubenzuron levels APHIS 

uses for grasshoppers and Mormon crickets are a minimal risk to bees.

However, diflubenzuron is toxic to larval honeybees (USEPA, 2018). It is slightly nontoxic to 

practically nontoxic to fish and birds and has very slight acute oral toxicity to mammals, with the most 

sensitive endpoint from exposure being the occurrence of methemoglobinemia (a condition that impairs 

the ability of the blood to carry oxygen). Minimal direct risk to amphibians and reptiles is expected, 

although there is some uncertainty due to lack of information (USDA APHIS, 2018c; USEPA, 2018).

Risk is low for most non-target species based on laboratory toxicity data, USEPA approved use rates 

and patterns, and additional mitigations such as the use of lower rates and RAATs that further reduces 

risk. Risk is greatest for sensitive terrestrial and aquatic invertebrates that may be exposed to 

diflubenzuron residues.

In a review of mammalian field studies, Dimilin® applications at a rate of 60 to 280 g a.i./ha had no 

effects on the abundance and reproduction in voles, field mice, and shrews (USDA FS, 2004). These 

rates are approximately three to 16 times greater than the highest application rate proposed in the 

program. Potential indirect impacts from application of diflubenzuron on small mammals includes loss 

of habitat or food items. Mice on treated plots consumed fewer lepidopterans (order of insects that 

includes butterflies and moths) larvae compared to controls; however, the total amount of food 

consumed did not differ between treated and untreated plots. Body measurements, weight, and fat 

content in mice collected from treated and non-treated areas did not differ. 

Poisoning of insectivorous birds by diflubenzuron after spraying in orchards at labeled rates is unlikely 

due to low toxicity (Muzzarelli, 1986). The primary concern for bird species is related to an indirect 

effect on insectivorous species from a decrease in insect prey. At the proposed application rates, 

grasshoppers have the highest risk of being impacted while other taxa have a much reduced risk because 

the lack of effects seen in multiple field studies on other taxa of invertebrates at use rates much higher 

than those proposed for the program. Shifting diets in insectivorous birds in response to prey densities is 

not uncommon in undisturbed areas (Rosenberg et al., 1982; Cooper et al., 1990; Sample et al., 1993).

Indirect risk to fish species can be defined as a loss of habitat or prey base that provides food and shelter 

for fish populations, however these impacts are not expected based on the available fish and invertebrate 

toxicity data (USDA APHIS, 2018c). A review of several aquatic field studies demonstrated that when 
24

effects were observed it was at diflubenzuron levels not expected from program activities (Fischer and 

Hall, 1992; USEPA, 1997; Eisler, 2000; USDA FS, 2004). 

Diflubenzuron applications have the potential to affect chitin production in various other beneficial 

terrestrial invertebrates. Multiple field studies in a variety of application settings, including grasshopper 

control, have been conducted regarding the impacts of diflubenzuron to terrestrial invertebrates. Based 

on the available data, sensitivity of terrestrial invertebrates to diflubenzuron is highly variable depending 

on which group of insects and which life stages are being exposed. Immature grasshoppers, beetle 

larvae, lepidopteran larvae, and chewing herbivorous insects appear to be more susceptible to 

diflubenzuron than other invertebrates. Within this group, however, grasshoppers appear to be more 

sensitive to the proposed use rates for the program. Honeybees, parasitic wasps, predatory insects, and 

sucking insects show greater tolerance to diflubenzuron exposure (Murphy et al., 1994; Eisler, 2000;

USDA FS, 2004). 

Diflubenzuron is moderately toxic to spiders and mites (USDA APHIS, 2018c). Deakle and Bradley 

(1982) measured the effects of four diflubenzuron applications on predators of Heliothis spp. at a rate of 

0.06 lb a.i. /ac and found no effects on several predator groups. This supported earlier studies by Keever 

et al. (1977) that demonstrated no effects on the arthropod predator community after multiple 

applications of diflubenzuron in cotton fields. Grasshopper integrated pest management (IPM) field 

studies have shown diflubenzuron to have a minimal impact on ants, spiders, predatory beetles, and 

scavenger beetles. There was no significant reduction in populations of these species from seven to 76 

days after treatment. Although ant populations exhibited declines of up to 50 percent, these reductions 

were temporary, and population recovery was described as immediate (Catangui et al., 1996).

Insecticide applications to rangelands have the potential to impact pollinators, and in turn, vegetation 

and various rangeland species that depend on pollinated vegetation. Based on the review of laboratory 

and field toxicity data for terrestrial invertebrates, applications of diflubenzuron are expected to have 

minimal risk to pollinators of terrestrial plants. The use of RAATs provide additional benefits by using 

reduced rates and creating untreated swaths within the spray block that will further reduce the potential 

risk to pollinators.

Adverse human health effects from ground or aerial ULV applications of diflubenzuron to control 

grasshoppers are not expected based on the low acute toxicity of diflubenzuron and low potential for 

human exposure. The adverse health effects of diflubenzuron to mammals and humans involves damage 

to hemoglobin in blood and the transport of oxygen. Diflubenzuron causes the formation of 

methemoglobin. Methemoglobin is a form of hemoglobin that is not able to transport oxygen (USDA 

FS, 2004). USEPA classifies diflubenzuron as non-carcinogenic to humans (USEPA, 2015b). 

Program workers adverse health risks are not likely when diflubenzuron is applied according to label 

directions that reduce or eliminate exposures. Adverse health risk to the general public in treatment areas 

is not expected due to the low potential for exposure resulting from low population density in the 

treatment areas, adherence to label requirements, program measures designed to reduce exposure to the 

public, and low toxicity to mammals.

c) Reduced Area Agent Treatments (RAATs) 

The use of RAATS is the most common application method for all program insecticides and would 

continue to be so accept in rare pest conditions that warrant full coverage and higher rates. The goal of 

the RAATs strategy is to suppress grasshopper populations to a desired level, rather than to reduce those 

populations to the greatest possible extent. This strategy has both economic and environmental benefits. 

APHIS would apply a single application of insecticide per year, typically using a RAATs strategy that 

decreases the rate of insecticide applied by either using lower insecticide concentrations, or by 
25

alternating one or more treatment swaths. Usually RAATs applications use both options. The RAATs 

strategy suppresses grasshoppers within treated swaths, while conserving grasshopper predators and 

parasites in swaths that are not treated. 

The concept of reducing the treatment area of insecticides while also applying less insecticide per 

treated acre was developed in 1995, with the first field tests of RAATs in Wyoming (Lockwood and 

Schell, 1997). Applications can be made either aerially or with ground-based equipment (Deneke and 

Keyser, 2011). Studies using the RAATs strategy have shown good control (up to 85% of that achieved 

with a traditional blanket insecticide application) at a significantly lower cost and less insecticide, and 

with a markedly higher abundance of non-target organisms following application (Lockwood et al., 

2000; Deneke and Keyser, 2011). Levels of control may also depend on variables such as body size of 

targeted grasshoppers, growth rate of forage, and the amount of coverage obtained by the spray 

applications (Deneke and Keyser, 2011). Control rates may also be augmented by the necrophilic and 

necrophagic behavior of grasshoppers, in which grasshoppers are attracted to volatile fatty acids 

emanating from cadavers of dead grasshoppers and move into treated swaths to cannibalize cadavers 

(Lockwood et al., 2002; Smith and Lockwood, 2003). Under optimal conditions, RAATs decrease 

control costs, as well as host plant losses and environmental effects (Lockwood et al., 2000; Lockwood 

et al., 2002). 

The efficacy of a RAATs strategy in reducing grasshoppers is, therefore, less than conventional 

treatments and more variable. Foster et al. (2000) reported that grasshopper mortality using RAATs was 

reduced 2 to 15% from conventional treatments, depending on the insecticide, while Lockwood et al. 

(2000) reported 0 to 26% difference in mortality between conventional and RAATs methods. APHIS 

will consider the effects of not suppressing grasshoppers to the greatest extent possible as part of the 

treatment planning process. 

RAATs reduces treatment costs and conserves non-target biological resources in untreated areas. The 

potential economic advantages of RAATs was proposed by Larsen and Foster (1996), and empirically 

demonstrated by Lockwood and Schell (1997). Widespread efforts to communicate the advantages of 

RAATs across the Western States were undertaken in 1998, and have continued on an annual basis. The 

viability of RAATs at an operational scale was initially demonstrated by Lockwood et al. (2000), and 

subsequently confirmed by Foster et al. (2000). The first government agencies to adopt RAATs in their 

grasshopper suppression programs were the Platte and Goshen County Weed and Pest Districts in 

Wyoming; they also funded research at the University of Wyoming to support the initial studies in 1995. 

This method is now commonly used by government agencies and private landowners in States where 

grasshopper control is required.

Reduced rates should prove beneficial for the environment. All APHIS grasshopper treatments using 

carbaryl, or diflubenzuron, are conducted in adherence with USEPA-approved label directions. Labeled 

application rates for grasshopper control tend to be lower than rates used against other pests. In addition, 

use rates proposed for grasshopper control by APHIS are lower than rates used by private landowners.

3. Experimental Treatments Alternative

Experimental Metarhizium robertsii Applications 

Metarhizium is a common entomopathogenic fungus genus containing several species, all of which are 

host-restricted to the Arthropoda, with some having greater host specificity to an insect family, or even a 

group of related genera. Once considered a single species based on morphology but split into a number 
26

of species based on DNA sequence data, the genus is found worldwide and is commonly used as a 

management alternative to chemicals (USDA, 2000; Lomer et al., 2001; Zimmerman, 2007; Roberts, 

2018; Zhang et al. 2019). Two Metarhizium, M. brunneum strain F52 and M. anisopliae ESF1, are 

registered with the USEPA as insecticides and are commercially used against a range of pest insects. 

No harm is expected to humans from exposure to Metarhizium by ingesting, inhaling, or touching 

products containing this active ingredient. No toxicity or adverse effects were seen when the active 

ingredient was tested in laboratory animals. M. anisopliae has undergone extensive toxicology testing 

for its registration in Africa and the registration of Green Guard in Australia. There has been no 

demonstrated adverse effect on humans from these products. There is a potential for an allergic reaction 

to dry conidia if a person is extensively exposed to the product and has a preexisting allergy to fungal 

spores. Metarhizium use in this program is not expected to cause adverse impacts to soil, water, or air. 

No adverse impacts from the use of Metarhizium biopesticides have been observed in almost 20 years of 

field trials in other countries. 

From 2005 to 2017, a massive project (led by Donald W. Roberts, Utah State University, in 

collaboration with USDA and others, and funded by APHIS-PPQ-S&T) was undertaken to collect 

38,052 soil samples from across the 17 western states, from areas that were historically known to have 

large populations of grasshoppers and/or Mormon crickets. The purpose of these collections was to 

locate a domestic alternative to the nonindigenous M. acridum, used around the world for management 

of grasshopper (usually locust) populations, particularly in Australia and sub-Sahelian Africa, but also in 

Mexico and Brazil. The use of such a pathogen would be highly useful to the Program as a biopesticide. 

Approximately 2,400 new isolates of Metarhizium spp., Beauveria spp. and other entomopathogenic 

fungi were found. Many of these fungi isolates were selected for lab and field trials with grasshoppers 

and Mormon crickets, the most promising being strain DWR2009 belonging to the species M. robertsii

(Bischoff et al., 2009). The DWR2009 isolate is still undergoing lab and field testing for efficacy against 

orthopterans. This species is closely related to M. anisopliae, which is commonly found worldwide and 

discernible only on the basis of diagnostic DNA sequences (Roberts, 2018). 

There is the potential for prolonged persistence in the environment of a domestic isolate from one area 

brought to another. Despite this possibility, potential environmental impact is minimal given the 

widespread and common nature of Metarhizium in the western United States and because the DWR2009 

isolate have been chosen for their optimized effects on orthopterans (Roberts, 2018). Although 

entomopathogenic fungi can reduce grasshopper populations, a substantial portion of the treated 

population are able to resist the infection through thermoregulation. Molecular systematics analyses (by 

the Roberts Lab; Bischoff et al., 2009; Kepler et al., 2014; Mayerhofer et al., 2019) revealed DWR2009 

is very closely related to many other strains within M. robertsii, all of which are basically biologically 

equivalent to each other. In fact, Metarhizium robertsii can only be really differentiated from other 

species by a multiplexed PCR assay based on two gene sequences. Furthermore, it is likely that 

persistence effects would mirror those found to be the case for M. anisopliae and M. acridum. Both of 

these species need optimal temperature ranges to thrive, as well as relatively humid conditions 

(Zimmerman, 2007; EA, 2010). In particular, M. acridum does not persist in semi-arid and arid 

environments, which is what rangeland habitats are, where U.S. grasshopper outbreaks occur (EA, 

2010). If the DWR2009 strain derived biopesticide is spread outside of the experimental plots 

exceptional rates of fungal infection are not anticipated. Since M. anisopliae is a generalist 

entomopathogen, lethal effects on non-target arthropods have been reported, but are more commonly 

observed in laboratory experiments than in the field. Plus, such effects are dependent on how the 

pathogen is applied; i.e., its intended target and application method play roles in non-target effects 

(Zimmerman, 2007). During experiments, the Rangeland Unit will spray ultra-low volumes (on 10 acres 

or less) of DWR2009 on grasshopper and Mormon cricket species from aircraft, or through the 
27

FAASSTT system. The Rangeland Unit may also coat small amounts of grasshopper bait with the 

DWR2009.

For the following four reasons, overall environmental impact by experimental studies utilizing 

Metarhizium robertsii applications should not be significant: 1) various strains of the pathogen are 

already common in rangeland habitats; 2) “behavioral fever” enables species to often “burn out” the 

infection by basking, allowing infected grasshoppers and Mormon crickets to escape death by mycosis; 

3) fungal pathogens are fairly susceptible to heat and ultraviolet light, greatly reducing the 

environmental persistence of spores to a few days on treated foliage or ground; and 4) at least three days 

of 98-100% relative humidity is required for fungal outgrowth and sporulation (reproduction) from 

infected cadavers (Lomer et al., 2001; Zimmerman, 2007; EA, 2010; Roberts, 2018).

Experimental LinOilEx Applications

LinOilEx (Formulation 103) is a non-traditional pesticide alternative still in the early stages of 

development. Its mode of action appears to be topical, often inducing a “freezing” effect in treated 

specimens whereby they appear to have been mid-movement when they die. Previous studies by its 

creator using locusts and katydids showed promise in its efficacy (Abdelatti and Hartbauer, 2019), so the 

Rangeland Unit decided to test it. Initial Mormon cricket microplot field studies and grasshopper lab 

studies are intriguing and warrant further field investigations via microplot cage experiments. The 

formulation is proprietary, but includes linseed oil, lecithin, wintergreen oil, and caraway oil mixed into 

a bicarbonate emulsion.

Target effects on locust and katydids in initial studies were high while non-target results were mixed, 

with one tested beetle species, as well as wheat seedlings, experiencing almost no impact. Another tested 

beetle species did experience relatively high mortality, but well-below target levels (Abdelatti and 

Hartbauer, 2019). The mode of action appears to be topical, meaning that direct contact with the 

formulation is needed to induce mortality. The Rangeland Unit’s initial studies demonstrated that 

indirect contact, by spraying vegetation, did not induce mortality. Together, these data suggest that 

overall environmental impact by experimental studies utilizing LinOilEx applications is expected to be 

relatively minimal.

B. Other Environmental Considerations

1. Cumulative Impacts

Cumulative impact, as defined in the Council on Environmental Quality (CEQ) NEPA implementing 

regulations (40 CFR § 1508.7) “is the impact on the environment which results from the incremental 

impact of the action when added to the past, present, and reasonably foreseeable future actions 

regardless of what agency (Federal or non-Federal) or person undertakes such actions. Cumulative 

impacts can result from individually minor but collectively significant actions taking place over a period 

of time.”

Potential cumulative impacts associated with the No Action alternative where APHIS would not take 

part in any grasshopper suppression program include the continued increase in grasshopper populations 

and potential expansion of populations into neighboring range and cropland. In addition, State and 

private land managers could apply insecticides to manage grasshopper populations however, land 

managers may opt not to use RAATs, which would increase insecticides applied to the environment. 

Increased insecticide use from the lack of coordination and RAAT applications where suitable could 
28

increase the exposure risk to non-target species and the environment. In addition, land managers may 

not employ the extra program measures designed to reduce exposure to the public and the environment. 

Potential cumulative impacts associated with the Preferred Alternative are not expected to be significant 

because the program applies an insecticide application once during a treatment. The program may treat 

an area with different insecticides, but does not overlap the treatments. The program does not mix or 

combine insecticides. Based on historical outbreaks in the United States, the probability of an outbreak 

occurring in the same area where treatment occurred in the previous year is unlikely; however, given 

time, populations eventually will reach economically damaging thresholds and require treatment. The 

insecticide application reduces the insect population down to levels that cause an acceptable level of 

economic damage. The duration of treatment activity, which is relatively short since it is a one-time 

application, and the lack of repeated treatments in the same area in the same year reduce the possibility 

of significant cumulative impacts.

Potential cumulative impacts resulting from the use of insecticides include insect pest resistance, 

synergistic chemical effects, chemical persistence and bioaccumulation in the environment. The 

program use of reduced insecticide application rates (i.e. ULV and RAATs) are expected to mitigate the 

development of insect resistance to the insecticides. Grasshopper outbreaks in the United States occur 

cyclically so applications do not occur to the same population over time further eliminating the selection 

pressure increasing the chances of insecticide resistance.

The insecticides proposed for use in the program have a variety of agricultural and non-agricultural uses.

There may be an increased use of these insecticides in an area under suppression when private, State, or 

Federal entities make applications to control other pests. Although APHIS is unaware of any, land 

managers could potentially do herbicide treatments in areas we treated, but they would not treat for 

GHMC. However, the vast majority of the land where program treatments occur is uncultivated 

rangeland and additional treatments by land owners or managers are very uncommon making possible 

cumulative or synergistic chemical effects extremely unlikely. 

The insecticides proposed for use in the grasshopper program are not anticipated to persist in the 

environment or bioaccumulate. Therefore, a grasshopper outbreak that occurs in an area previously 

treated for grasshoppers is unlikely to cause an accumulation of insecticides from previous program 

treatments.

The proposed experimental treatments are short-term and would take place in a very limited area. The 

purpose of the field tests conducted by the Rangeland Unit will help determine whether APHIS would 

eventually include Metarhizium robertsii (isolate DWR2009) based biopesticides as an option for the 

Program. The data generated by these studies would likely be used as part of the EPA registration 

process for this biopesticide. Inclusion of effective and environmentally friendly insecticides would 

provide the Program additional control options for grasshoppers and Mormon crickets in sensitive 

habitats. If successful, the use of M. robertsii could decrease the amount of chemical insecticides used in 

rangeland against grasshoppers and Mormon crickets.

2. Executive Order No. 12898, Federal Actions to Address Environmental Justice in 

Minority Populations and Low-Income Populations

Federal agencies identify and address the disproportionately high and adverse human health or 

environmental effects of their proposed activities, as described in Executive Order (EO) 12898, “Federal 

Actions to Address Environmental Justice in Minority Populations and Low-Income Populations.”
29

APHIS has evaluated the proposed grasshopper program and has determined that there is no 

disproportionately high and adverse human health or environmental effects on minority populations or 

low-income populations. 

3. Executive Order No. 13045, Protection of Children from Environmental Health Risks 

and Safety Risks

Federal agencies consider a proposed action’s potential effects on children to comply with EO 13045, 

“Protection of Children from Environmental Health Risks and Safety Risks.” This EO requires each 

Federal agency, consistent with its mission, to identify and assess environmental health and safety risks 

that may disproportionately affect children and to ensure its policies, programs, activities, and standards 

address disproportionate risks to children that result from environmental health risks or safety risks. 

APHIS has developed agency guidance for its programs to follow to ensure the protection of children 

(USDA APHIS, 1999).

APHIS’ HHERAs evaluated the potential exposure to each insecticide used in the program and risks 

associated with these insecticides to residents, including children. The HHERAs for the proposed 

program insecticides, located at http://www.aphis.usda.gov/plant-health/grasshopper, suggest that no 

disproportionate risks to children, as part of the general public, are anticipated.

APHIS grasshopper insecticide treatments are conducted in rural rangeland areas, where agriculture is a 

primary industry. The areas consist of widely scattered, single, rural dwellings in ranching communities 

with low population density. The program notifies residents within treatment areas, or their designated 

representatives, prior to proposed operations to reduce the potential for incidental exposure to residents 

including children. Treatments are conducted primarily on open rangelands where children would not be 

expected to be present during treatment or to enter should there be any restricted entry period after 

treatment. The program also implements mitigation measures beyond label requirements to ensure that 

no treatments occur within the required buffer zones from structures, such as a 500-foot treatment buffer 

zone from schools and recreational areas. Program insecticides are not applied while school buses are 

operating in the treatment area (USDA APHIS, 2016).

Impacts on children will be minimized by the implementation of the treatment guidelines:

Aerial Broadcast Applications (Liquid Chemical Methods)

• Notify all residents within treatment areas, or their designated representatives, prior to proposed 

operations. Advise them of the control method to be used, the proposed method of application, 

and precautions to be taken (e.g., advise parents to keep children and pets indoors during ULV 

treatment). Refer to label recommendations related to restricted entry period.

• No treatments will occur over congested urban areas. For all flights over congested areas, the 

contractor must submit a plan to the appropriate Federal Aviation Administration District Office 

and this office must approve of the plan; a letter of authorization signed by city or town 

authorities must accompany each plan. Whenever possible, the program plans aerial ferrying and 

turnaround routes to avoid flights over congested areas, bodies of water, and other sensitive areas 

that are not to be treated.

Aerial Application of Baits (Dry Chemical Methods)

• Do not apply within 500 feet of any school or recreational facility.

Ultra-Low-Volume Aerial Application (Liquid Chemical Methods)

• Do not spray while school buses are operating in the treatment area.

• Do not apply within 500 feet of any school or recreational facility.
30

4. Tribal Consultation

Executive Order 13175 "Consultation and Coordination with Indian Tribal Governments," calls for 

agency communication and collaboration with tribal officials when proposed Federal actions have 

potential tribal implications. The Archaeological Resources Protection Act of 1979 (16 U.S.C. §§ 470aamm), secures the protection of archaeological resources and sites on public and tribal lands.

Prior to the treatment season, program personnel notify Tribal land managers of the potential for 

grasshopper and Mormon cricket outbreaks on their lands. Consultation with local Tribal representatives 

takes place prior to treatment programs to inform fully the Tribes of possible actions APHIS may take 

on Tribal lands. Treatments typically do not occur at cultural sites, and drift from a program treatment at 

such locations is not expected to adversely affect natural surfaces, such as rock formations and carvings. 

APHIS would also confer with the appropriate Tribal authority to ensure that the timing and location of 

a planned program treatment does not coincide or conflict with cultural events or observances on Tribal 

lands.

5. Executive Order 13186, Responsibilities of Federal Agencies to Protect Migratory 

Birds

The Migratory Bird Treaty Act (MBTA) of 1918 (16 U.S.C. 703–712) established a Federal prohibition, 

unless permitted by regulations, to pursue, hunt, take, capture, kill, attempt to take, capture or kill, 

possess, offer for sale, sell, offer to purchase, purchase, deliver for shipment, ship, cause to be shipped, 

deliver for transportation, transport, cause to be transported, carry, or cause to be carried by any means 

whatever, receive for shipment, transportation or carriage, or export, at any time, or in any manner, any 

migratory bird or any part, nest, or egg of any such bird.

Executive Order 13186 directs Federal agencies taking actions with a measurable negative effect on 

migratory bird populations to develop and implement a Memorandum of Understanding with the 

USFWS that promotes the conservation of migratory bird populations. On August 2, 2012, a 

Memorandum of Understanding between APHIS and the USFWS was signed to facilitate the 

implementation of this Executive Order.

In accordance with Executive Order 13186, MBTA, APHIS will support the conservation intent of the 

migratory bird conventions by integrating bird conservation principles, measures, and practices into 

agency activities and by avoiding or minimizing, to the extent practicable, adverse impacts on migratory 

bird resources when conducting agency actions. Impacts are minimized as a result of buffers to water, 

habitat, nesting areas, riparian areas, and the use of RAATs. For any given treatment, only a portion of 

the environment will be treated, therefore minimizing potential impacts to migratory bird populations. 

6. Endangered Species Act

Section 7 of the Endangered Species Act (ESA) and its implementing regulations require Federal 

agencies to ensure their actions are not likely to jeopardize the continued existence of listed threatened 

or endangered (listed) species, or result in the destruction or adverse modification of critical habitat.

Numerous federally-listed species and areas of designated critical habitat occur within the 17-State 

program area, although not all occur within or near potential grasshopper suppression areas or within the 

area under consideration by through this EA. 

APHIS considers whether listed species, species proposed for listing, experimental populations, or 

critical habitat are present in the proposed suppression area. Before treatments are conducted, APHIS 

contacts the U.S Fish and Wildlife Service (USFWS) or the National Marine Fisheries Service (NMFS) 

(where applicable) to determine if listed species are present in the suppression area, and whether 

mitigations or protection measures must be implemented to protect listed species or critical habitat. 
31

APHIS completed a programmatic Section 7 consultation with NMFS for use of carbaryl, malathion, 

and diflubenzuron to suppress grasshoppers in the 17-state program area because of the listed salmonid 

(Oncorhynchus spp.) and critical habitat. To minimize the possibility of insecticides from reaching 

salmonid habitat, APHIS implements the following protection measures:

• RAATs are used in all areas adjacent to salmonid habitat

• ULV sprays are used, which are between 50 and 66% of the USEPA recommended rate

• Insecticides are not aerially applied in 3,500 foot buffer zones for carbaryl or malathion or in 

1,500 foot buffer zones for diflubenzuron along stream corridors

• Insecticides will not be applied when wind speeds exceed 10 miles per hour. APHIS will attempt 

to avoid insecticide application if the wind is blowing towards salmonid habitat

• Insecticide applications are avoided when precipitation is likely or during temperature inversions

APHIS determined that with the implementation of these measures, the grasshopper suppression 

program may affect, but is not likely to adversely affect listed salmonids or designated critical habitat in 

the program area. NMFS concurred with this determination in a letter dated April 12, 2010. APHIS will 

consult with NMFS at the local level if there could be co-occurrence of program chlorantraniliprole 

applications and listed salmonids.

APHIS submitted a programmatic biological assessment and requested consultation with USFWS on 

March 9, 2015 for use of carbaryl, malathion, diflubenzuron, and chlorantraniliprole for grasshopper 

suppression in the 17-state program area. With the incorporation and use of application buffers and other 

operational procedures APHIS anticipates that any impacts associated with the use and fate of program 

insecticides will be insignificant and discountable to listed species and their habitats. Based on an 

assessment of the potential exposure, response, and subsequent risk characterization of program 

operations, APHIS concludes the proposed action is not likely to adversely affect listed species or 

critical habitat in the program area. APHIS has requested concurrence from the USFWS on these 

determinations. Until this programmatic Section 7 consultation with USFWS is completed, APHIS will 

conduct consultations with USFWS field offices at the local level.

Local consultations are being conducted between APHIS and FWS regarding section 7 of the Endangered 

Species Act. Species consulted on are outlined in the assessment section of this document. The FWS 

Letter of Concurrence is located in Appendix7. 

7. Bald and Golden Eagle Protection Act

The Bald and Golden Eagle Protection Act (16 U.S.C. 668–668c) prohibits anyone, without a permit 

issued by the Secretary of the Interior, from “taking” bald eagles, including their parts, nests, or eggs.

During the breeding season, bald eagles are sensitive to a variety of human activities. Grasshopper 

management activities could cause disturbance of nesting eagles, depending on the duration, noise 

levels, extent of the area affected by the activity, prior experiences that eagles have with humans, and 

tolerance of the individual nesting pair. Also, disruptive activities in or near eagle foraging areas can 

interfere with bald eagle feeding, reducing chances of survival. USFWS has provided recommendations 

for avoiding disturbance at foraging areas and communal roost sites that are applicable to grasshopper 

management programs (USFWS, 2007).

No toxic effects are anticipated on eagles as a direct consequence of insecticide treatments. Toxic effects 

on the principle food source, fish, are not expected because insecticide treatments will not be conducted 

over rivers or lakes. Buffers protective of aquatic biota are applied to their habitats to ensure that there 

are no indirect effects from loss of prey.
32

8. Additional Species of Concern

There may be species that are of special concern to land management agencies, the public, or other 

groups and individuals in proposed treatment areas. For example, the sage grouse populations have 

declined throughout most of their entire range, with habitat loss being a major factor in their decline.

Grasshopper suppression programs reduce grasshoppers and at least some other insects in the treatment 

area that can be a food item for sage grouse chicks. As indicated in previous sections on impacts to 

birds, there is low potential that the program insecticides would be toxic to sage grouse, either by direct 

exposure to the insecticides or indirectly through immature sage grouse eating moribund grasshoppers. 

Because grasshopper numbers are so high in an outbreak year, treatments would not likely reduce the 

number of grasshoppers below levels present in a normal year. Should grasshoppers be unavailable in 

small, localized areas, sage grouse chicks may consume other insects, which sage grouse chicks likely 

do in years when grasshopper numbers are naturally low. By suppressing grasshoppers, rangeland 

vegetation is available for use by other species, including sage grouse, and rangeland areas are less 

susceptible to invasive plants that may be undesirable for sage grouse habitat.

9. Fires and Human Health Hazards

Various compounds are released in smoke during wildland fires, including carbon monoxide (CO), 

carbon dioxide, nitrous oxides, sulfur dioxide, hydrogen chloride, aerosols, polynuclear aromatic 

hydrocarbons contained within fine particulate matter (a byproduct of the combustion of organic matter 

such as wood), aldehydes, and most notably formaldehyde produced from the incomplete combustion of 

burning biomass (Reisen and Brown, 2009; Burling et al., 2010; Broyles, 2013). Particulate matter, CO, 

benzene, acrolein, and formaldehyde have been identified as compounds of particular concern in 

wildland fire smoke (Reinhardt and Ottmar, 2004). 

Many of the naturally occurring products associated with combustion from wildfires may also be present 

as a result of combustion of program insecticides that are applied to rangeland. These combustion 

byproducts will be at lower quantities due to the short half-lives of most of the program insecticides and 

their low use rates. Other minor combustion products specific to each insecticide may also be present as 

a result of combustion from a rangeland fire but these are typically less toxic based on available human 

health data (http://www.aphis.usda.gov/plant-health/grasshopper).

The safety data sheet (SDS) for each insecticide identifies these combustion products for each 

insecticide as well as recommendations for PPE. The PPE is similar to what typically is used in fighting 

wildfires. Material applied in the field will be at a much lower concentration than what would occur in a 

fire involving a concentrated formulation. Therefore the PPE worn by rangeland firefighters would also 

be protective of any additional exposure resulting from the burning of residual insecticides. 

10. Cultural and Historical Resources

Federal actions must seek to avoid, minimize, and mitigate potential negative impacts to cultural and 

historic resources as part of compliance with the National Historic Preservation Act (NHPA), the 

Archaeological Resources Protection Act of 1979, and NEPA. Section 106 of the NHPA requires 

Federal agencies to provide the Advisory Council on Historic Preservation with an opportunity to 

comment on their findings.
33

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44

VI. Listing of Agencies and Persons Consulted 

John Nystedt, Fish and Wildlife Biologist, U.S. Fish and Wildlife 

Service. Flagstaff Suboffice

323 N. Leroux Street, Suite 201

Flagstaff, Arizona 86001

Brenda Smith, Fish and Wildlife Biologist, U.S. Fish and Wildlife 

Service Flagstaff Suboffice

323 N. Leroux Street, Suite 201

Flagstaff, Arizona 86001

Shaula Hedwall, Fish and Wildlife Biologist, U.S. Fish and Wildlife 

Service Flagstaff Suboffice

323 N. Leroux Street, Suite 201

Flagstaff, Arizona 86001

Brian J. Wooldridge, Fish and Wildlife Biologist, U. S. Fish and Wildlife Service 

Flagstaff Suboffice

323 N. Leroux St., Suite 201

Flagstaff, AZ 86001

Terry Rambler, Tribal Chairman, San Carlos Apache Tribe

P.O. Box 0

#3 San Carlos 

Avenue 

San Carlos, Arizona 85550

Clark Richins, Land Operation Coordinator, San Carlos Agency, Bureau of Indian 

Affairs #3 San Carlos Avenue

San Carlos, Arizona 85550

Teresa Goseyun, Rangeland Management Specialist, San Carlos Apache Tribe

#3 San Carlos Avenue

San Carlos, Arizona 85550

Daniel Juan, Biologist, San Carlos Apache 

Tribe PO Box 97

San Carlos, Arizona 85550

Paul Buck, Soil Scientist, San Carlos Apache 

Tribe PO Box 0

San Carlos, Arizona 85550

Michael J. Herder, Arizona Strip District Manager, BLM

345 East Riverside Drive

St. George, Utah 84790
45

Ben Otte, Rangeland Management Specialist, Arizona Strip District Manager, BLM

345 East Riverside Drive

St. George, Utah 84790

Justin Reeves, Rangeland Management Specialist, Arizona Strip District Manager, BLM

345 East Riverside Drive

St. George, Utah 84790

Travis Largent, Wildlife Biologist

Kaibab National Forest, Williams and Tusayan Ranger Districts

742 S Clover Rd.

Williams, AZ 86046

Kelly Hetzler, Forester, Inventory and GIS, San Carlos Apache 

Tribe PO Box 0

San Carlos, Arizona 85550

Victoria Wesley, San Carlos Apache Tribe, 

Forestry PO Box 0

San Carlos, Arizona 85550

Daniel Juan, Wildlife Technician, San Carlos Apache 

Tribe PO Box 0

San Carlos, Arizona 85550

Jeff McFadden, Wildlife Technician, San Carlos Apache 

Tribe PO Box 0

San Carlos, Arizona 85550

Sabrina Tuttle, Ph.D., Assistant Extension Agent, Gila County Cooperative 

Extension, U of A, San Carlos Apache Reservation

PO Box 850

San Carlos, Arizona 85550

Toni L. Strauss, District Ranger, 

Coronado National Forest

Safford Ranger District

711 14th Ave., Suite D 

Safford, Arizona 85546

Anne L. Casey, Wildlife Biologist, 

Coronado National Forest

Safford Ranger District

711 14th Ave., Suite D 

Safford, Arizona 85546
46

Annette Bravo, Program Manager

Hualapai Department of Natural Resources Wildlife, Fisheries, and Parks Program

P.O. Box 300/947 Rodeo Way 

Peach Springs, AZ 86434

Donata Dupree, Range Specialist

Hualapai Department of Natural Resources Wildlife, Fisheries, and Parks Program

P.O. Box 300/947 Rodeo Way 

Peach Springs, AZ 86434

Robbie Honani, Agriculture Specialist

Hualapai Department of Natural Resources Wildlife, Fisheries, and Parks Program

P.O. Box 300/947 Rodeo Way 

Peach Springs, AZ 86434

 Joe Montana, GIS / Water Technician

 Hualapai Department of Natural Resources Wildlife, Fisheries, and Parks Program

P.O. Box 300/947 

Rodeo Way 

Peach Springs, AZ 86434

Jennifer Cordova, Wildlife Specialist II, 

Arizona Game and Fish Dept. 

PO Box 397

Seligman, AZ 86337
Table 1. Representative Species

Plants:

Emory oak (Quercus emoryi)

Alligator bark juniper (Juniperus deppeana) 

Pinyon pine (Pinus edulis)

Arizona cypress (Cupressus arizonica) 

Gray oak (Quercus grisea)

Canyon live oak (Quercus chrysolepis) 

Arizona oak (Quercus arizonica) 

Western chokecherry (Prunus virginiana) 

Manzanita (Arctostaphylos pungens) 

Shrub live-oak (Quercus turbinella) 

Sugar sumac (Rhus ovata)

Ceanothus (Ceanothus greggii) 

California buckthorn (Rhamnus crocea) 

Yellowleaf silktassel (Garrya flavescens) 

Box elder (Acer negundo)

Crucifixion thorn (Canotia holocantha) 

Penstemon (Penstemon palmeri) 

Desert verbena (Verbena wrightii) 

Right buckwheat (Eriogonum wrightii) 

Narrowleaf yerbasanta (Eriodictyon 

angustifolium)

Sideoats grama (Bouteloua curtipendula) 

Cane bluestem (Bothriochloa barbinodis) 

Plains lovegrass (Eragrostis intermedia) 

Black grama (Bouteloua eriopoda)

Blue grama (Bouteloua gracilis)

Fendler three-awn (Aristida fendleriana) 

Agave (Agave parryi)

Beargrass (Nolina microcarpa) 

Sotol (Dasylirion wheeleri) 

Banana yucca (Yucca baccata)

Arizona sycamore (Platanus wrightii) Arizona walnut (Juglans major)

Tamarisk (Tamarix sp.) Seepwillow (Baccharis glutinosa).

Netleaf hackberry (Celtis reticulata) Velvet ash (Fraxinusvelutina), 

Mexican elderberry (Sambuccus mexicanus)

Mammals:

Cliff chipmunk (Eutamias dorsalis)

White-throated woodrat (Neotoma albigula) 

Mule deer (Odocoileus hemionus)

Brush mouse (Peromyscus boylei)

Rock mouse (P. difficilis)

White-footed mouse (P. leucopus)

Eastern cottontail (Sylvilagus floridanus holzeri)

Birds:

Rufous-crowned sparrow (Aimophila ruficeps) 

Scrub jay (Aphelocoma coerulescens)

Canyon wren (Catherpes mexicanus)

Rufous-sided towhee (Pipilo erythrophthalmus) 

Brown towhee (P. fuscus)

Bushtit (Psaltriparus minimus)

Black-chinned sparrow (Spizella atrogularis) 

Crissal thrasher (Toxostoma dorsale) 

Burrowing owl (Athene cunicularia)
 Amphibians and reptiles:

 Glossy snake (Arizona elegans) 

 Arizona alligator lizard (Gerrhonotus kingi) 

 Arizona night lizard (Zantusia arizonae)

 Desert striped whipsnake (M. taeniatus)

 Eastern fence lizard (S. undulates)

 Night snake (Hypsiglena torquata)

 Side-blotched lizard (Uta stansburiana) 

 Sonoran mountain kingsnake (Lampropeltis pyromelana)

 Southwestern blind snake (Leptotyphlopshumilis)

 Sonora whipsnake (Masticophis bilineatus

 Sonoran lyre snake (Trimorphodon biscutatus lambda)

 Texas lyre snake (T. b. vilkinsoni)

 Western fence lizard (Scleroporus occidentalis) 

 Western blackhead snake (Tantilla planiceps) 

 Western rattlesnake (Crotalus viridis)
APPENDIX 1: 

APHIS Rangeland Grasshopper and Mormon Cricket Suppression Program

FY-2020 Treatment Guidelines

The objectives of the APHIS Rangeland Grasshopper and Mormon Cricket Suppression Program 

are to 1) conduct surveys in the Western States; 2) provide technical assistance to land managers 

and private landowners; and 3) when funds permit, suppress economically damaging grasshopper 

and Mormon cricket outbreaks on Federal, Tribal, State, and/or private rangeland. The Plant 

Protection Act of 2000 provides APHIS the authority to take these actions.

General Guidelines for Grasshopper / Mormon Cricket Treatments

1) All treatments must be in accordance with:

a) the Plant Protection Act of 2000;

b) applicable environmental laws and policies such as: the National Environmental 

Policy Act, the Endangered Species Act, the Federal Insecticide, Fungicide, and 

Rodenticide Act, and the Clean Water Act (including National Pollutant Discharge 

Elimination System requirements – if applicable);

c) applicable state laws;

d) APHIS Directives pertaining to the proposed action;

e) Memoranda of Understanding with other Federal agencies.

2) Subject to the availability of funds, upon request of the administering agency, the 

agriculture department of an affected State, or private landowners, APHIS, to protect 

rangeland, shall immediately treat Federal, Tribal, State, or private lands that are infested 

with grasshoppers or Mormon crickets at levels of economic infestation, unless APHIS 

determines that delaying treatment will not cause greater economic damage to adjacent 

owners of rangeland. In carrying out this section, APHIS shall work in conjunction with 

other Federal, State, Tribal, and private prevention, control, or suppression efforts to 

protect rangeland.

3) Prior to the treatment season, conduct meetings or provide guidance that allows for public 

participation in the decision making process. In addition, notify Federal, State and Tribal 

land managers and private landowners of the potential for grasshopper and Mormon 

cricket outbreaks on their lands. Request that the land manager / land owner advise APHIS 

of any sensitive sites that may exist in the proposed treatment areas.

4) Consultation with local Tribal representatives will take place prior to treatment programs 

to fully inform the Tribes of possible actions APHIS may take on Tribal lands.

5) On APHIS run suppression programs, the Federal government will bear the cost of 

treatment up to 100 percent on Federal and Tribal Trust land, 50 percent of the cost on 

State land, and 33 percent of cost on private land. There is an additional 16.15% charge, 

however, on any funds received by APHIS for federal involvement with suppression 

treatments.

6) Land managers are responsible for the overall management of rangeland under their 
control to prevent or reduce the severity of grasshopper and Mormon cricket outbreaks. 

Land managers are encouraged to have implemented Integrated Pest Management

Systems prior to requesting a treatment. In the absence of available funding or in the 

place of APHIS funding, the Federal land management agency, Tribal authority or other 

party/ies may opt to reimburse APHIS for suppression treatments. Interagency 

agreements or reimbursement agreements must be completed prior to the start of 

treatments which will be charged thereto.

7) There are situations where APHIS may be requested to treat rangeland that also includes 

small areas where crops are being grown (typically less than 10 percent of the treatment 

area). In those situations, the crop owner pays the entire treatment costs on the croplands.

NOTE: The insecticide being considered must be labeled for the included crop as well as 

rangeland and current Worker Protection Standards must be followed by the applicator 

and private landowner.

8) In some cases, rangeland treatments may be conducted by other federal agencies (e.g., 

Forest Service, Bureau of Land Management, or Bureau of Indian Affairs) or by nonfederal entities (e.g., Grazing Association or County Pest District). APHIS may choose to 

assist these groups in a variety of ways, such as:

a) loaning equipment (an agreement may be required):

b) contributing in-kind services such as surveys to determine insect species, instars, and 

infestation levels;

c) monitoring for effectiveness of the treatment;

d) providing technical guidance.

9) In areas considered for treatment, State-registered beekeepers and organic producers

shall be notified in advance of proposed treatments. If necessary, non-treated buffer 

zones can be established.

Operational Procedures

GENERAL PROCEDURES FOR ALL AERIAL AND GROUND APPLICATIONS

1) Follow all applicable Federal, Tribal, State and local laws and regulations in 

conducting grasshopper and Mormon cricket suppression treatments.

2) Notify residents within treatment areas, or their designated representatives, prior to

proposed operations. Advise them of the control method to be used, proposed method of 

application, and precautions to be taken.

3) One of the following insecticides that are labeled for rangeland use can be used 

for a suppression treatment of grasshoppers and Mormon crickets:

a) Carbaryl

i) solid bait

ii) ultra-low volume (ULV) spray

b) Diflubenzuron ULV spray

c) Malathion ULV spray
4) Do not apply insecticides directly to water bodies (defined herein as reservoirs, lakes,

ponds, pools left by seasonal streams, springs, wetlands, and perennial streams and

rivers).

Furthermore, provide the following buffers for water bodies:

• 500-foot buffer with aerial liquid insecticide.

• 200 foot buffer with ground liquid insecticide.

• 200-foot buffer with aerial bait.

• 50-foot buffer with ground bait.

5) Instruct program personnel in the safe use of equipment, materials and procedures; 

supervise to ensure safety procedures are properly followed.

6) Conduct mixing, loading, and unloading in an approved area where an accidental spill 

would not contaminate a water body.

7) Each aerial suppression program will have a Contracting Officer’s Representative (COR)

OR a Treatment Manager on site. Each State will have at least one COR available to assist 

the Contracting Officer (CO) in GH/MC aerial suppression programs.

NOTE: A Treatment Manager is an individual that the COR has delegated authority 

to oversee the actual suppression treatment; someone who is on the treatment site 

and overseeing / coordinating the treatment and communicating with the COR. No 

specific training is required, but knowledge of the Aerial Application Manual and 

treatment experience is critical; attendance to the Aerial Applicators Workshop is 

very beneficial.

8) Each suppression program will conduct environmental monitoring as outlined in the

current year’s Environmental Monitoring Plan.

APHIS will assess and monitor rangeland treatments for the efficacy of the treatment, 

to verify that a suppression treatment program has properly been implemented, and to 

assure that any environmentally sensitive sites are protected.

9) APHIS reporting requirements associated with grasshopper / Mormon cricket 

suppression treatments can be found in the APHIS Grasshopper Program Guidebook:

http://www.aphis.usda.gov/import_export/plants/manuals/domestic/downloads/grasshopper.pd

f

SPECIFIC PROCEDURES FOR AERIAL APPLICATIONS

1) APHIS Aerial treatment contracts will adhere to the current year’s Statement of 

Work (SOW).
2) Minimize the potential for drift and volatilization by not using ULV sprays 

when the following conditions exist in the spray area:

a) Wind velocity exceeds 10 miles per hour (unless state law requires lower 

wind speed);

b) Rain is falling or is imminent;

c) Dew is present over large areas within the treatment block;

d) There is air turbulence that could affect the spray deposition;

e) Temperature inversions (ground temperature higher than air temperature) develop

and deposition onto the ground is affected.

3) Weather conditions will be monitored and documented during application and 

treatment will be suspended when conditions could jeopardize the correct spray 

placement or pilotsafety.

4) Application aircraft will fly at a median altitude of 1 to 1.5 times the wingspan of the

aircraft whenever possible or as specified by the COR or the Treatment Manager.

5) Whenever possible, plan aerial ferrying and turnaround routes to avoid flights over

congested areas, water bodies, and other sensitive areas that are not to be treated.
2020 Operational Procedures

_____________________________________________________________

ALL METHODS

1. Follow all applicable Federal, State, Tribal and local environmental laws and regulations in 

conducting GH&MC suppression treatment operations.

2. Hold public meetings well in advance of proposed programs. Arrange for public 

announcements to encourage public input into the decision making process.

3. Notify Federal and State land managers and private cooperators of GH&MC infestations on 

their lands. This program will describe estimated boundaries, severity of infestations, and 

optimal time frames for treatment and control options. The notifications will request the land 

manager to advise USDA-APHIS-PPQ of any sensitive areas (e.g., parks, recreation areas, 

etc.) that may exist in the proposed treatment areas.

4. Obtain request, in writing, from land managers and owners for suppression treatments to be 

undertaken on their land. When these requests originate as telephone calls, ensure that a 

follow-up letter is received before the expenditure of USDA-APHIS-PPQ funds.

5. Avoid residences and other premises whose occupants object to their property being treated, 

except when treatments are mandatory under State law. In cases when State law requires 

treatment but land owners or occupants object to the treatments, USDA-APHIS-PPQ will 

cooperate to the extent authorized by Federal and State laws.

 

6. Endangered Species (also see operational procedures listed under each control method in the 

EIS).

a. Formal consultation will be accomplished with the U.S. Fish and Wildlife Service 

(USFWS) at the national level or designated points of contact. The Portland Regional 

Office has been designated as the official contact for formal consultation. 

Communications with the USFWS at the local level will be conducted to consider 

activities outside the National Biological Opinion.

b. State-listed endangered and threatened species, Federal candidate species, and 

other sensitive areas will be addressed in the site-specific Environmental Assessment 

(EA).

7. Instruct all program personnel in the use of equipment, materials and procedures; supervise 

to ensure procedures are followed properly.

AERIAL BROADCAST APPLICATIONS (LIQUID CHEMICAL METHODS)

1. Strictly follow all EPA and State approved label instructions for chemical insecticides.
2. Aircraft, dispersal equipment and pilots that do not meet all contract requirements of the 

2003 Prospectus will not be allowed to operate on the program.

3. All USDA-APHIS-PPQ employees who plan, supervise, recommend or perform pesticide 

treatments must be certified under the USDA-APHIS-PPQ Certification Plan. They are also 

required to know and meet any additional qualifications or requirements of the State wherein 

they perform duties involving pesticide use.

4. Notify all residents in treatment areas, or their designated representatives, prior to proposed 

operations. Advise them of the control method to be used, the proposed method of 

application, and precautions to be taken (e.g., advise parents to keep children and pets 

indoors during ULV treatment). Refer to label requirements related to restricted entry 

period.

5. Use Global Positioning System (GPS) coordinates for pilot guidance on the parameters of the 

spray block. Ground flagging or markers should accompany GPS coordinates in delineating 

the project area as well as areas to omit from treatment (e.g., boundaries and buffers for 

bodies of water, habitats of protected species, etc.). 

6. Provide two-way communication equipment for all field personnel. Communication will be 

available for continuous contact among all units (including pilots) involved in any program.

7. In advance of any treatment, stock safety kits, thermometers, flagging material, wind gauges, 

spray-deposit samplers and daily aircraft records, and make them available to relevant 

personnel.

8. No treatments will occur over congested urban areas. For all flights over congested areas, 

the contractor must submit a plan to the appropriate FAA District Office and this office must 

approve of the plan; a letter of authorization signed by city or town authorities must 

accompany each plan. Whenever possible, plan aerial ferrying and turnaround routes to 

avoid flights over congested areas, bodies of water, and other sensitive areas that are not to 

be treated.

9. Pesticide Container Disposal. All insecticide containers must be stored and disposed of 

properly. Rinse solution for drums may be used as diluent in preparing spray tank mixes, or 

it may be collected and stored for subsequent disposal in accordance with label instructions. 

One of the following methods for disposal (listed in order of preference) must be used: 

a. Require chemical companies, distributors, or suppliers to accept the triple-rinsed 

containers.

b. Crush and/or puncture the empty triple-rinsed containers, report on Form AD-112 to 

Property Services, Field Servicing Office, Minneapolis, MN, and dispose of as scrap 

metal.
c. Other methods as approved locally in concurrence with Safety, Health and Environmental 

Security (SHES; Bill Benson, 301-734-5577).

10. Conduct mixing, loading, and unloading in an approved area where an accidental spill will 

not contaminate a stream or other body of water.

11. In the event of an accidental spill, follow the procedures set forth in PPQ Guidelines for 

Managing Pesticide Spills (USDA APHIS, Treatment Manual, 1996, pages 11.17-11.26).

12. Pre-spray reconnaissance flights may be conducted to ensure that pilots are familiar with 

program area boundaries, buffer zones, and any other areas that are not to be treated.

13. Notify local law enforcement agencies and fire officials of pesticide storage areas and 

treatment blocks.

Aerial Application of Baits (Dry Chemical Methods)

1. Do not use blowers for loading baits into the hopper, as blowers can cause packing of baits.

2. The bait-hopper must be dust-tight. It must empty completely with uninterrupted flow, and it 

must be vented to avoid erratic flow of materials.

3. There must be a dust-tight gate in the hopper throat to avoid leakage during ferry flights 

when flying over sensitive areas and during turnarounds. Linkage between the gate and its 

cockpit control handle must be secure. Gate stops are required to ensure that the hopper gate 

is opened to exactly the same position each time. Screw-type stops are preferred, whereas 

stops that are adjustable through a series of holes or notches are not acceptable. The gate 

stop must be at the gate and not in the cockpit on Category A and B aircraft.

4. Aerial Bait 

a. Protective clothing will be worn by all pilots, loaders and field personnel, as required by 

the label and APHIS Safety and Health Manual, Chapter 11.

b. Empty bags must be disposed of according to EPA regulations. 

c. Follow label requirements when treatment areas contain reservoirs, lakes, ponds, pools 

left by seasonal streams, springs, wetlands, and perennial streams and rivers. The label 

indicates no direct application to water or wetlands.

d. Do not apply within 500 feet of any school or recreational facility.

e. Do not apply where the water table is high, where leaching or runoff is likely, or when 

precipitation is imminent.

f. Follow label recommendations when treatment areas contain oats, barley, and rye (fall 

treatments). For all other crops, observe the minimum days required between final 

application and harvest.
g. Follow label requirements when treatment areas contain commercial bee hives. 

Ultra-Low-Volume (ULV) Aerial Application (Liquid Chemical Methods)

1. To minimize drift and volatilization, do not use ULV sprays when any of the following 

conditions exist in the spray area: wind velocity exceeds 10 miles per hour (unless lower 

wind speed required under State law); rain is falling or is imminent; weather is foggy; F; air 

turbulence that could seriouslynormally when temperatures exceed 80 affect the normal 

spray pattern; and temperature inversions that could lead to off-site movement of spray.

2. Weather conditions on treatment areas will be monitored by trained personnel before and 

during application. Operations will be suspended anytime it appears that weather conditions 

could jeopardize the safe placement of the spray on target areas.

3. Do not apply when foliage is wet.

4. Do not apply chemical ULV directly to any crop for which it is not labeled, unless an 

exemption has been granted under Section 18 of the Federal Insecticide, Fungicide and 

Rodenticide Act (FIFRA).

5. All APHIS project personnel will have baseline cholinesterase tests before the first 

application of insecticide and on a routine basis as described in the APHIS Safety and Health 

Manual. It is recommended that contract, State, and private project personnel also participate 

in a cholinesterase monitoring program.

6. Require unprotected workers to stay out of treated areas, per the label re-entry requirements, 

or until the insecticide has dried, whichever period is longer.

7. Use nozzle types and sizes, spray system pressure, and nozzle orientation as specified in the 

2003 Prospectus or as approved by Aircraft and Equipment Operations (AEO) and the 

Contracting Officer.

8. It is mandatory that the insecticide tank on the aircraft be adequately vented to provide for 

unrestricted flow, in the event that the load must be jettisoned.

9. Do not spray while school buses are operating in the treatment area.

10. Protective long-sleeved work clothing will be worn by all pilots, loaders, and field personnel, 

as specified in the label and the APHIS Safety and Health Manual. 

11. Follow label requirements that indicate not applying directly onto reservoirs, lakes, ponds, 

pools left by seasonal streams, springs, wetlands, and perennial streams and rivers. 

12. Do not apply where the water table is high or where leaching or surface runoff is likely.
13. Do not apply within 500 feet of any school or recreational facility.

14. Protection of Bees:

a. When off-season or early-season planning indicates an area may require treatment, send 

early notification letters and maps to all registered apiarists in the State or near the area.

b. Pre-spray reconnaissance flights may be conducted to ensure that all honey bees and all 

other bees used as commercial crop pollinators have been moved or protected. Should 

bees remain, ensure that the beekeeper received notice of the impending treatment and 

that programs are conducted in accordance with State law.

c. If treatments are planned within 4 miles of areas where alkali or leaf cutter bees are being 

used for increasing the yield of alfalfa seed, monitor wind conditions and other drift 

factors closely. Do not apply ULV sprays when drift could reach these areas. In all such 

cases, use spray samplers (dye cards) near those areas

d. Do not apply ULV diflubenzuron, carbaryl, or malathion to any blooming crops or allow 

it to drift onto blooming crops if commercial bees are visiting the area. 
APPENDIX 2: Map of Affected Environment
APPENDIX 3: Map of Proposed Action Areas Covered by the Two Environmental 

Assessments for the state of Arizona. (EA# AZ-20-01 and AZ-20-02)
APPENDIX 4: Map of the Hualapai Tribe Proposed Action Area...
APPENDIX 5: Map of the San Carlos Apache Tribal Proposed Action Area. 
APPENDIX 6: Map of the Coronado National Forest Proposed Action Area.
APPENDIX 7: FWS/NMFS Correspondence 










Appendix 8: APHIS response to public comments on the Arizona draft EAs 

(EA Number: AZ-20-01 and EA Number: AZ-20-02) 

USDA APHIS received two public responses to the publication of the Draft EA. Public 

Comments were received from the Xerces Society and from the Center for Biological Diversity.

Comments similar in nature were grouped under one response. Comments that were editorial in

nature or requested additional citations are not addressed in the appendix but were incorporated 

into the final EA, where appropriate. The Grasshopper Program has decided not to 

use chlorantraniliprole or malathion in Arizona during 2020, any exposure scenarios which the 

commenters are concerned about are not relevant, and all references to these two chemicals

were removed from the final EA. 

Comment 1 

USDA APHIS received one comment about the EAs providing little in the way of solid 

information about where, how, and when the treatments may actually occur within the counties 

covered under the EAs, during the year 2020, which makes it impossible to determine if effects

would actually be significant or not. 

APHIS described the purpose and need for grasshopper suppression treatments, potential 

treatment options, the affected environment within the state, and an analysis of the potential 

environmental consequences in the Draft EAs that were made available for public comment. 

These documents become programmatic because APHIS cannot precisely predict where an 

outbreak will occur each year; we only know that outbreaks will occur, and treatments in a 

timely manner will be absolutely necessary. The emergency response aspect is why site-specific 

treatment details cannot be known, analyzed, and published in advance. APHIS relies on its 

emergency provisions within its NEPA Implementing regulations (7 CFR 372.10) to address 

these situations. 

Please be aware that local agreements with Tribal Nations may preclude disclosure of Tribal 

information to the public or outside of APHIS without the consent of the Tribal Administrator. 

Individuals may request information on the specific treatment areas on Tribal Lands from the 

individual Tribal Nations. 

Comment 2 

USDA APHIS received one comment concerning the lack of transparency about the location of 

actual treatment areas, particularly on public lands, being a disservice to the public that prevents 

the public from reviewing sufficient information to be able to gauge justification for and the risks 

involved in the suppression effort. 

APHIS did not withhold the location of actual treatment areas while preparing the Draft EA, but 

rather those facts were not known at that time because economically damaging grasshopper 

populations had not become apparent. See previous comment concerning the prevention of the 

commenter’s ability to gauge the justification and risks of treatments within the proposed action 

areas. 
Comment 3 

APHIS received one comment urging APHIS to provide the public with maps of specific 

treatment areas and proposed treatment strategies (including proposed date of application and 

chemical and rate to be used), immediately after approving any treatment and at least 14 days 

prior to implementation of any treatment. This comment suggested that this specific information 

be posted at the APHIS website as soon as it is available, sent to interested parties, and made 

available for public comment. 

In most circumstances, APHIS is not able to accurately predict specific treatment areas 

and treatment strategies months or even weeks before grasshopper populations reach economic 

infestation levels. The need for rapid and effective response when an outbreak occurs limits the 

options available to APHIS to inform the public other than those stakeholders who could be 

directly affected by the actual application. APHIS typically does not have 14 days between 

planning a treatment and the actual application because of the rapid population growth 

and potential damage of grasshopper infestations. 

In Arizona, local agreements with Tribal Nations prohibit disclosure of Tribal information to the 

public or outside of APHIS, without the consent of the Tribal Administrator. The treatment areas 

on Tribal Lands will have to be provided by the individual Tribal Nations. 

Comment 4 

APHIS received one comment that mentioned “APHIS’ procedure to approve or disapprove 

treatments based on a cost-benefit analysis performed using the “Hopper” model” and that is 

site-specific data are not available or current, APHIS must use protective values as defaults in 

Hopper.” 

The “Hopper” model is an older model and southwestern states (including AZ) were never 

included in the model. 

In Arizona, general site specific data, which is used to determine treatments in real time and 

gathered at time of actual surveys are used to make treatment decisions. The general site specific 

data include: grasshopper densities, species complex, dominant species, dominant life stage, 

grazing allotment terrain, soil types, range conditions, local weather patterns (wind, temp., 

precipitation),slope and aspect for hatching beds, animal unit months (AUM’s) present 

in grazing allotment, forage damage estimates, number of potential AUM’s consumed by 

grasshopper population, potential AUM’s managed for allotment and value of the AUM, 

estimated cost of replacement feed for livestock, rotational time frame for grazing allotments, 

number of livestock in grazing allotment. These are all factors taken into consideration during 

the survey season. 

The individual site-specific data for determining treatment areas on Tribal Lands is provided by 

the individual Tribal Nations. 

Comment 5 

APHIS received one comment concerning how analysis of projected economic injury levels and 

ultimately, treatment decisions, might be determined in the absence of site-specific data 
(specifically rangeland productivity and composition, precipitation and soil moisture, 

accessibility and cost of alternative forage, effectiveness of treatment, cost of treatment, timing 

of treatment, and grasshopper population density, life stage, and species composition).

See comment 4 above. In Arizona, general site specific data, which is used to determine 

treatments in real time and gathered at time of actual surveys are used to make treatment 

decisions.

Comment 6

APHIS received one comment related to disclosing its analysis for each of the seven variables 

mentioned in comment 5.

The site specific data that is used to determine treatments in real-time is gathered at the time of 

actual surveys. This data is not available at the time that the environmental assessments are 

prepared. See comment 4 for an example of general site specific data used to determine 

treatments.

In Arizona, local agreements with Tribal Nations prohibit disclosure of Tribal information to the 

public or outside of APHIS, without the consent of the Tribal Administrator. The treatment areas 

and site-specific information from Tribal Lands will have to be provided by the individual 

Tribal Nations.

Comment 7

APHIS received one comment about providing the public with a more precise definition of when 

the threshold for spraying has been met.

Economic thresholds are variable based on the value of protected resources and management 

objectives. Baseline thresholds for Mormon crickets are 2 per sq. yd. and grasshoppers are 

8 per sq. yd., though neither of those thresholds guarantees justification for treatment alone. All 

of the site-specific data mentioned in comment 4 above are also considered for Arizona.

Comment 8

APHIS received one comment urging APHIS to delay the publication of EA and FONSI until 

after treatment requests are received and all treatment areas have been delineated and are 

identified to the public.

In Arizona, letters of request were received dated January 28, 2020 and Tribal Local MOU 

Request, dated March 19, 2019 expires December 2024. Treatment areas are delineated during 

the survey process. The grazing allotments, which meet the treatment criteria, are identified to 

the requesting land managers. In the case of Tribal Lands see responses to comments 

4, 5, and 6.
Comment 9

APHIS received one comment regarding the EAs list four insecticide options (diflubenzuron, 

carbaryl, malathion, and chlorantraniliprole), and states that the choice of which to use will be 

site-specific, without being clear about how that choice of insecticide is made.

In Arizona, hot spot treatments are conducted using ground equipment. The insecticides 

mentioned are options which could be used. However, the Grasshopper Program has decided 

not to use chlorantraniliprole or malathion in Arizona during 2020.

Letters of Request in previous years from land managers may be specific to use a particular 

insecticide and not treat during specific times of the day or on weekends. These requests are 

adhered to in Arizona. The letters of request come from the individual land managers. The 

decision to use diflubenzuron is determined by the life stage of the dominant species within the 

outbreak population. In the case of early instars, diflubenzuron, the preferred insecticide, 

can produce 90 to 97% mortality. If the window for the use of diflubenzuron closes, as a result of 

treatment delays, then the only other option would be the use of Carbaryl 2% or 5% bait. There 

are certain species which are susceptible to carbaryl bait. If the species complex present in the 

outbreak is not susceptible to bait and the diflubenzuron window is closed, then no treatments 

will occur. This is discussed with the requesting land managers. Carbaryl XLR Plus (liquid 

formulation) is not being used in 2020.

The final EA has been updated to reflect the changes in the program.

Comment 10

APHIS received one comment concerning BeeREX calculating the expected environmental 

concentration (EEC) of diflubenzuron in pollen and nectar from foliar overspray as 1.76 mg/kg, 

which is equivalent to 1760 ppb.

Nectar and pollen values in BeeREX are based on residues that would be expected to occur from 

direct pesticide applications to long grass which is a food source EPA estimates in its T-REX 

model. These assumptions may overestimate expected residues of diflubenzuron in pollen and 

nectar. Available data for diflubenzuron pollen residues in crops show a low frequency of 

occurrence and low concentrations. The concentration in pollen will depend on application 

rates and when applications are made relative to flower bloom. Program applications of 

diflubenzuron are at the lower end of labeled use rates for Dimilin due to the sensitivity of 

Orthoptera. In addition, the Program uses rates less than the current labeled rates for 

grasshoppers and other labeled crops and makes only one application.

Comment 11

APHIS received one comment regarding chitin synthesis and its important in the early life stages 

of insects, as they molt and form a new exoskeleton in various growth stages. The specific 

concern was that aquatic guideline tests, (or terrestrial invertebrate acute tests), which typically 

run for 48 hours, may not capture a molting stage, and thus underrepresent acute toxicity. Single 

doses may cause mortality, if received at a vulnerable time, and consequently, conclusions from 

RQs based on acute toxicity studies for invertebrates may not fully represent actual risk.
APHIS agrees that chitin synthesis is a critical function for terrestrial and aquatic invertebrates.

APHIS in its risk assessments prepared for each Program insecticide summarized available 

acute and chronic toxicity data. This would include studies of short duration such as 48 to 96 

hours as well as much longer term studies that would evaluate continuous exposures during 

critical life stages and development.

Comment 12

APHIS received the following comment, “For honey bees (the surrogate species for risk 

assessment in the absence of other data), USEPA (2018) reported a chronic 21-day ED50 and 

NOAEL of 0.012 and <0.0064 μg a.i./larva, respectively. Utilizing these values 

in BeeREX (EPA’s model that calculates risk quotients for bees) and assuming an application 

rate of 0.016 lb. ai/ac, BeeREX calculates an acute dietary risk quotient of 18.13 and a chronic 

dietary risk quotient of 33.99. (A threshold value is 1.0). Risk quotients this high above 1.0 

indicate a high concern for exposed bees.”

BeeREX is a tier one screening level model used by EPA to assess potential risk to pollinators. 

Estimates of risk quotients are used to determine if there is a presumption of risk that requires 

additional evaluation. APHIS also relies on available field data to further characterize the risks 

of Program insecticides to terrestrial and aquatic invertebrates, where available. A limitation 

of BeeREX is it does not account for pesticide degradation that would normally occur in 

Program treatments.

Nectar and pollen values in BeeREX are based on residues that would be expected to occur from 

direct pesticide applications to long grass which is a food source EPA estimates in its T-REX 

model. These assumptions may overestimate expected residues of diflubenzuron in pollen and 

nectar. Available data for diflubenzuron pollen residues in crops with higher use rates show a 

low frequency of occurrence and low concentrations. The concentration in pollen will depend 

on application rates and when applications are made relative to flower blooming.

Diflubenzuron Program applications are at the lower end of labeled use rates for Dimilin due to 

the sensitivity of Orthoptera. In addition, the Program uses rates less than the current labeled 

rates and makes one application.

Comment 13

APHIS received one comment, regarding the EIS disclosing that under some 

circumstances, Dimilin may be quite persistent; field dissipation studies in California citrus and 

Oregon apple orchards reported half-live values of 68.2 to 78 days. Rangeland persistence is 

unfortunately not available, but diflubenzuron applied to plants remains adsorbed to leaf surfaces 

for several weeks.

Diflubenzuron persistence varies depending on site conditions. Diflubenzuron degradation is 

microbially mediated with soil aerobic half-lives much less than dissipation half-lives. While 

dissipation half-lives may extend up to 78 days, they have also been shown to be much less under 

other use patterns.
Comment 14

APHIS received the following comment, “APHIS discounted the pollinator risk by claiming that 

studies finding significant effects to pollinators utilized doses far above levels that would be used 

in grasshopper control. Unfortunately, this does not appear to be true for all studies 

cited. Mommaerts et al. (2006) conducted dose-response assays and found that exposure to 

diflubenzuron resulted in reproductive effects in Bombus terrestris, with only the doses at 0.001 

of maximum field recommended concentrations (MFRC) in pollen and 0.0001 in sugar water 

resulting in effects statistically similar to controls. The MFRC for diflubenzuron is listed in the 

study as 288 mg/L (equivalent to 288,000 ppb). At 1/10,000 of this level, diflubenzuron effects 

would be similar to controls only at levels at or below 28.8 ppb while at 1/1000 of this level, 

diflubenzuron “no effect” concentrations would be equivalent to 288 ppb. This analysis thus 

shows the opposite of what APHIS claims – that the effective dose for reproductive effects is 

actually far below the EEC expected for diflubenzuron at RAATS rates used in grasshopper 

suppression. This raises concern that the application of diflubenzuron at the specified RAATS 

rates may cause severe impacts to bee reproduction within treated areas.”

APHIS relied on available laboratory and field collected data for each Program insecticide to 

summarize risks to terrestrial invertebrates. In evaluating studies, APHIS also evaluated likely 

routes of exposure for Program treatments. Estimates of exposure using the EPA tier one 

screening model likely overestimate potential residues in pollen and nectar. 

Comment 15

APHIS received six comments about chlorantraniliprole.

Chlorantraniliprole is not proposed for use in 2020. The final EA has been updated to reflect the 

changes in the program.

Comment 16

APHIS received one comment concerning malathion being found to cause jeopardy in 1,284 

endangered species according to recent nationwide Biological Opinions

APHIS recognizes that EPA and the Services are continuing to develop updated national level 

consultations. APHIS currently consults with the Services at the State level for the Grasshopper 

program to ensure program activities do not adversely affect protected species or their critical 

habitat. 

See response to comment 9 for use of Malathion in Arizona.

Comment 17

APHIS received one comment regarding the EPA determined that carbaryl is likely to adversely 

affect 1,542 species.

The Endangered Species Act section 7 pesticide consultation process between the U.S. Fish and 

Wildlife Service and the National Marine Fisheries Service (the Services, collectively) and the 

EPA specifically concerns FIFRA pesticide registration and reregistration in the United States, 

including all registered uses of a pesticide. The state-level Biological Assessments for APHIS 
invasive species programs are separate from any consultations conducted in association with 

pesticide registration and reregistration process. 

The Agricultural Improvement Act of 2018 (Farm Bill) created a partnership between USDA, 

EPA, the Services, and the Council on Environmental Quality to improve the consultation 

process for pesticide registration and reregistration. USDA is committed to working to ensure 

consultations are conducted in a timely, transparent manner and based on the best available 

science. The Revised Method for National Level Listed Species Biological Evaluations of 

Conventional Pesticides provides a directionally improved path to ensuring that pesticides can 

continue to be used safely for agricultural production with minimal impacts to threatened and 

endangered species.

APHIS provided information about use of carbaryl to EPA for the FIFRA consultation for 

carbaryl. The Grasshopper Program use of carbaryl has in the past comprised substantially less 

than 1% of the percent crop treated (PCT) for rangeland use of carbaryl. This is the case for the 

reasonably foreseeable future. For rangeland, in the EPA BE, the Grasshopper Program’s very 

low usage was rounded up to <1% PCT, which gives an overestimate of rangeland acres treated 

and thus endangered species risk. APHIS use of carbaryl is even smaller compared to all uses of 

carbaryl. Further, the Grasshopper Program consults directly with the Services to ensure 

program activities do not adversely affect protected species or their critical habitat.

Comment 18

APHIS received the following comment, “The jeopardy and LAA calls for malathion and 

carbaryl should be included in the EAs and should preclude the use of these chemicals.”

APHIS consults directly with the U.S. Fish and Wildlife Service on treatments and methods. The 

U.S. Environmental Protection Agency’s on-going consultation on pesticide registration across 

all nationwide uses of program pesticides does not provide sufficiently detailed analysis or 

conclusions relevant to the Grasshopper Program.

Comment 19

APHIS received one comment that it should take into account the risk to native bees and 

butterflies from these treatments, especially those designated species of greatest conservation 

need. APHIS should constrain its treatments to take into account pollinator conservation needs, 

and improve its monitoring capability to try to understand what non-target effects actually occur 

as a result of the different treatments.

APHIS reduces the risk to native bees and pollinators through monitoring grasshopper and 

Mormon cricket populations and making pesticide applications in a manner that reduces the risk 

to this group of nontarget invertebrates. Monitoring grasshopper and Mormon cricket 

populations allows APHIS to determine if populations require treatment and to make treatments 

in a timely manner reducing pesticide use and emphasizing the use of Program insecticides that 

are not broad spectrum. Historical use of Program insecticides demonstrate that diflubenzuron 

is the preferred insecticide for use. Over 90% of the acreage treated by the Program has been 

with diflubenzuron. Diflubenzuron poses a reduced risk to native bees and pollinators compared 

to liquid carbaryl and malathion applications. In addition APHIS used RAATs to treat 
approximately 99% of the acres historically treated by the Program. APHIS also uses RAATs 

that are typically below the labeled RAAT rates further reducing the amount of insecticide used 

by the program. APHIS also emphasizes the use of carbaryl bait, where applicable, as a means 

to suppress pest populations while protecting native bees and pollinators. These methods of 

applications have been shown to be protective of nontarget invertebrates. These studies are 

referenced and summarized in the EIS.

Comment 20

APHIS received the following comment, This EA and the EIS claim that the use of untreated 

swaths will mitigate impacts to natural enemies, bees, and other wildlife. However, the width of 

the skipped swaths is not designated in advance in the EA, and there is no minimum width 

specified.

APHIS assumes that the reduced amount of pesticide that would occur using untreated swaths 

over a given treatment block will result in reduced risk to nontarget organisms by reducing 

exposure. The swath width can vary based on site specific conditions, however, the end result is 

reduced pesticide exposure over a treatment area. The EIS cites studies that demonstrate that the 

use of RAATs result in higher nontarget invertebrate populations compared to treatment blocks 

that did not use RAATs.

Comment 21

APHIS received two comments/recommendations about minimum swath widths, “Without 

knowing minimum (rather than maximum) swath widths that will be applied under this EA, it is 

hard to compare results from this study (Lockwood et al. 2000) to the results on non-targets 

expected under RAATS in this EA. 2). APHIS should commit to science-based methodologies to 

assess actual risk from the proposed treatments and institute minimum untreated swath widths 

wide enough to meaningfully minimize exposure to bees and other beneficials.”

In Arizona, treatments are applied using ground treatment equipment. The commenter references 

the work of Lockwood et al. 2000, this study looked at RAAT’s increasing swath widths in some 

instances by double skipping the untreated area. They also used ATV’s in their study which only 

have a minimum effect swath width of 30 feet. Presently in Arizona, using UTV’s with the ability 

to adjust the hopper height, using the same ATV spreader, the minimum effective swath width 

can be increased to 40 feet, thus also increasing the untreated swath to 40 feet. APHIS uses 

science based methodologies to assess treatment related benefits or risks. APHIS has for 

decades funded the Science and Technology Research Lab in Phoenix, Arizona, which is specific 

to Rangeland Grasshopper and Mormon Cricket Program research and development. It is the 

only one of its kind in the U.S. The S&T Lab in cooperation with 

ASU researchers have evaluated nontarget invertebrate impacts in the past and have made 

recommendations to the Program side of APHIS.

Comment 22

APHIS received the following comment, “Although the EIS included a quantitative analysis of 

drift anticipated from ULV aerial applications to estimate deposition into aquatic areas, an 

analysis is not presented or available to back up the assumption that untreated areas (skipped 

swath widths) will act as refugia for natural enemies, bees, and other wildlife.”
The EIS cites studies that demonstrate that the use of RAATs result in higher nontarget 

invertebrate populations compared to treatment blocks that did not use RAATs.

Comment 23

APHIS received three comments about the drift analysis described in the EA, 1) “The drift 

analysis described in the EA assumed a droplet spectra size of fine to very fine (median diameter 

= 137.5 μm). However, labels do not require a minimum droplet size for ULV applications over 

rangeland, and other uses of ULV technology for pest control assume much smaller droplet 

sizes. EPA’s (2018) Ecological Risk Assessment for diflubenzuron uses AgDrift to estimate the 

drift fraction from aerial LV applications, although it is unclear whether AgDrift is validated for 

the purposes of predicting deposition of insecticides applied using ULV technology. EPA 

assumed a volume mean diameter (VMD) of 90 μm [note that this is approximately 2/3 of the 

VMD used in the APHIS analysis]. Under EPA’s analysis, the drift fraction comprises 19% at 

150 ft.”, 2) “APHIS should disclose its quantitative analysis and the percent drift it expects--by 

distance-- into untreated swaths for each application method it proposes”, and 3) “APHIS must 

also specify in its operational procedures the use of nozzles that will result in droplet spectra that 

accord with its analysis”.

The VMD used by APHIS for diflubenzuron is the preferred median diameter used by the 

Program. APHIS recognizes that the range of droplet sizes can vary under a ULV application. 

Comment 24

APHIS received a comment that it is “unrealistic that APHIS can comply with mitigation 

measures designed to protect bees on pesticide labels “(e.g., bumble bees fly earlier and later in 

the day, diflubenzuron is toxic to developing forms, if plants are flowering, bees are active, etc.)

APHIS uses diflubenzuron at far-lower levels than allowed by the label, thereby minimizing 

risks to non-targets, such as bees. There have been several studies on diflubenzuron effects on 

bees, such as Schroeder et al. (1980) and insect growth regulator effects reviewed 

in Tasei (2001), which support the idea that the diflubenzuron levels APHIS uses for 

grasshoppers and Mormon crickets are a minimal risk to bees. APHIS also complies with any 

label requirements designed to minimize impacts to pollinators.

Comment 25

APHIS received the following comment, “Except for untreated swath widths, the EA is silent on 

how it will avoid impact to pollinators. The EAs do allow for some protections for managed 

pollinators in the Operational Procedures, but wild native pollinators are not even listed as 

"representative species" in Table 1. It has already been shown that within sprayed areas, risk 

quotients at expected application rates would be well above 1.0. Leaving skipped widths is also 

not a full solution at expected widths since, due to drift, untreated swaths are highly likely to be 

exposed to levels above risk quotients”.

APHIS uses diflubenzuron at far-lower levels than allowed by the label, thereby minimizing risks 

to non-targets. Additionally, APHIS commonly incorporates untreated swaths into its treatment 
programs, which have consistently demonstrated reduced impacts to non-target arthropods 

(Lockwood et al. (1999, 2001, 2002); Norelius and Lockwood (1999)).

Comment 26

APHIS received one comment regarding that APHIS must not ignore requirements listed on 

pesticide labels, nor make assumptions about its compliance with these when RAATS measures 

that will actually be taken are vague and unspecified.

APHIS complies with all applicable Federal and State pesticide label language when making 

pesticide treatments.

Comment 27

APHIS received the following comment: “While flexibility with these may have been 

appropriate at the EIS stage, it is not appropriate at the EA stage. APHIS must fully disclose its 

RAATS plan for each treatment in the EA, including specifying application method, chemical to 

be used, rate, and width of untreated swaths.”

RAATs are a dynamic treatment method based on the size of the treatment area, species complex, 

and density of target species. Specific details regarding RAATs cannot be determined until site 

specific data is collected during the 2020 survey season and an appropriate chemical is 

identified. Once a treatment is determined necessary, application method, untreated swath 

widths, chemical choice, and application rate are included in the bid for contracting.

In Arizona specifically, local agreements with Tribal Nations prohibit disclosure of Tribal 

information to the public or outside of APHIS, without the consent of the Tribal Administrator. 

The specific treatment areas on Tribal Lands will have to be provided by the individual Tribal 

Nations.

Comment 28

APHIS received one comment, “To be consistent with the Pollinator-Friendly BMPs for Federal 

Lands (see Comment 7), APHIS must go beyond the general statements on the pesticide labels 

and specify more exactly how its spray plan will further reduce exposure and risk to bees.”

See Comment 25

Comment 29

APHIS received the following comment, “The EAs describe the listed species potentially 

present, but does not include a letter of concurrence or other communication from FWS in AZ20-1. In AZ-20-1, the letter of concurrence attached indicates: "APHIS will employ buffer zones, 

within which no pesticide applications will occur, and will implement other conservation 

measures from the nine biological opinions issued by the FWS for the APHIS control program in 

18 western states, and subsequently consolidated in an October 3, 1995, letter from the FWS -

Mountain Prairie Region, to the Deputy Director, APHIS. APHIS will also employ buffer zones 

and other conservation measures from "Recommended Protection Measures for Pesticide 

Applications in Region 2 of the U.S. Fish and Wildlife Service" (USFWS, 2007a) for species not 

covered in the aforementioned consultations or whichever buffer is greater. APHIS does not 
include these conservation measures in the document nor does it provide any specificity about 

these conservation measures in the operational guidelines.”

The comment is contradictory and mentions that the letter of concurrence was not included in 

the EA, but then references language from the attached letter of concurrence. 

In Arizona the FWS letter of concurrence dated February 10, 2020, from the Arizona State office 

in Phoenix, is in appendix 7 of Draft EA# AZ-20-02. In Arizona, the FWS concurrence letter for 

Tribal Lands comes from the FWS Region 2 office in Albuquerque, NM. The lead biologist 

stated verbally that the concurrence was written and sent to the Regional office for signature. 

The Regional concurrence letter has been received dated April 1, 2020 for EA# AZ-20-01.

In Arizona, the general operational guidelines are provided in the EA’s to address protective 

measures for bodies of water without T&E species. The buffers for T&E species are addressed 

during the FWS Section 7 consultations. The ArcGIS map layers of T&E species and the buffers 

are taken into the field when delimiting treatment areas, this is done to insure that the buffered 

areas near the treatment areas correspond to the GIS data. The datasets are ground truthed in 

the field to ensure accuracy. When T&E species are associated with stock tanks, these buffers 

are physically measured using survey grade measuring devices and or rangefinders. The 

buffered areas are then flagged for visibility as no entry areas for applicators.

Comment 30

APHIS received one comment that the letter of concurrence mentions only two chemicals. It 

appears that no consultation was completed for the use of chlorantraniliprole. APHIS must not 

utilize active ingredients for which consultation is incomplete

Chlorantraniliprole is not proposed for use in 2020. The final EA has been updated to reflect the 

changes in the program.

See FWS letters of concurrence stated in previous response.

Comment 31

APHIS received two comments concerning operationally, how will listed species’ protected 

locations be identified for ground and aerial applicators? How will such locations, buffer widths 

listed in the protective measures, and any specific instructions (i.e. use of carbaryl bait only) for 

some species be mapped and communicated to applicators? APHIS must provide to applicators 

a set of clear set of directions outlining protective measures for the listed and proposed species 

found within this project area and not burden applicators with a confusing set of directions split 

between multiple tables.

In Arizona, the general operational guidelines are provided in the EA’s to address protective 

measures for bodies of water without T&E species. The buffers for T&E species are addressed 

during the FWS Section 7 consultations. The ArcGIS map layers of T&E species and the buffers 

are taken into the field when delimiting treatment areas, this is done to insure that the buffered 

areas near the treatment areas correspond to the GIS data. The datasets are ground truth in the 

field to ensure accuracy. When T&E species are associated with stock tanks, these buffers are 
physically measured using survey grade measuring devices and or rangefinders. The buffered

areas are then flagged for visibility as no entry areas for applicators.

Since Arizona treatments are conducted only using ground equipment the buffers and sensitive 

sites are all mapped and are in the hand of the applicator (as GPS shapefiles) during 

treatments. Arizona does not conduct aerial applications. During the daily briefings, if there is a 

question regarding buffers or sensitive sites it is addressed before treatment work that particular 

treatment day.

Comment 32

APHIS received one comment about pesticide specific conservation measures for each listed 

species, where appropriate, should be explicitly addressed and adopted.

Agreed upon mitigation measures address specific chemicals when conservation measures are 

warranted. These measures are agreed upon during the consultation process with the FWS and 

are applied in the field during application.

Comment 33

APHIS received one comment that APHIS should adopt the following operational guideline 

across all site-specific EAs: “Use Global Positioning System (GPS) coordinates for pilot 

guidance on the parameters of the spray block. Ground flagging or markers should accompany 

GPS coordinates in delineating the project area as well as areas to omit from treatment (e.g., 

boundaries and buffers for bodies of water, habitats of protected species, etc.).”

In Arizona, the use of Trimble GPS Navigation equipment is used to navigate and capture 

shapefiles of the treatment areas using ground equipment. All sensitive sites are buffered out 

of the treatment area using flagging which is highly visible to the applicator. All sensitive sites 

are reviewed in the daily briefing with APHIS personnel including the applicator working on the 

treatment site.

Comment 34

APHIS received one comment that, “APHIS states that it has no legal obligation to manage for 

vulnerable species not on the Endangered Species List. The essential role that pollinators play in 

the conservation of listed plant species is not addressed in the EAs and makes no mention of the 

fact that there are affirmative obligations incumbent on federal agencies with regard to protection 

of pollinators, regardless of whether they are federally listed including the 2014 Presidential 

Memorandum, the National Strategy to Promote the Health or Honey Bees and Other 

Pollinators, the Pollinator Friendly BMPs for Federal Land, and the Pollinator Research Action 

Item.”

APHIS considers the role of pollinators in any consultations conducted with the FWS to protect 

federally-listed plants. Mitigation measures, such as no treatment buffers are applied with 

consideration of the protection of pollinators that are important to a particular listed plant 

species.
APHIS also implements several BMP practices in their treatment strategies that are designed to 

protect nontarget invertebrates, including pollinators. APHIS minimizes insecticide use by using 

lower than labeled rates for all Program insecticides, alternating swaths during 

treatment, making only one application per season and minimizing use of liquid broad spectrum 

insecticides. APHIS also continues to evaluate new monitoring and control methods designed to 

increase the response to economically damaging populations of grasshoppers and Mormon 

crickets while protecting rangeland resources such as pollinators.

Comment 35

APHIS received one comment, “The EAs disclose species listed as sensitive but does not list 

Species of Conservation Concern, or whether the state of Utah designates any invertebrates as 

Species of Greatest Conservation Need.

This EA is for Arizona and not Utah. In Arizona, however, the Kanab amber snail is listed as an 

endangered species without critical habitat. It is isolated to Coconino County, Upper Grand 

Canyon area. Known habitat is eliminated from the action areas. Protective measures were 

addressed with FWS during local Section 7 consultations. The letter of concurrence dated 

February 10, 2020 from Phoenix State Office and FWS Region 2 Office dated April 1, 2020. 

Draft EA # AZ-20-02 appendix 7.

Comment 36

APHIS received one comment regarding, the EAs protections for at risk species, including the 

monarch butterfly which is currently being assessed for listing under the Endangered Species 

Act, are practically non-existent.

Under FWS Section 7 Act there is no requirement to consult on sensitive species. (See FWS letter 

of concurrence dated February 10, 2020 in Arizona Draft EA# AZ-20-02 Appendix 7, first 

paragraph last sentence. However, in Arizona when there is concern by land management 

agencies, federal, state, etc.; APHIS has implemented protective measures for species of concern 

which may be closely related to a T&E species. This is a cooperative effort by APHIS between 

FWS, Tribal Nations, Arizona Game & Fish or the requesting land management agency.

Comment 37

APHIS received one comment, “In the face of declining pollinator populations and the existence 

of federal directives for agencies to support and conserve pollinators and their habitat, APHIS 

must not conduct business as usual. APHIS should identify the at-risk pollinator species 

potentially present in the geographic area of the EAs and map their ranges prior to approving any 

treatment requests. Prior to treatment, APHIS should survey for presence of host plants and 

ensure that it has identified specific, actionable measures it will take to protect monarch habitat 

and the habitat of at-risk butterfly species from contamination that may occur as a result of 

exposure to treatment, such as designating a 125-ft buffer around identified habitat. Some ways 

to enact protections for at-risk species above and beyond those included in the EAs include:

● Survey for butterfly host plants and avoid any applications to host plants.

● Time pesticide applications to avoid exposure to at risk species.

● Do not apply pesticides (especially insecticides) when monarchs (adult and immature) are 

present or expected to be present.
● Avoid aerial applications.

● Avoid using malathion and liquid carbaryl.

● Include large buffers around all water sources, including intermittent and ephemeral streams, 

wetlands, and permanent streams and rivers, as well as threatened and endangered species 

habitat, honey bee hives, and any human-inhabited area. For example, Tepedino (2000) 

recommends a three-mile buffer around rare plant populations, as many of these are pollinated 

by solitary bees that are susceptible to grasshopper control chemicals.”

APHIS includes many of the proposed measures to minimize risks to non-target organisms and 

human health. These are summarized in the recent EIS. For example, no treatment buffers are 

applied to all water bodies and to areas where the public may potentially be exposed to Program 

applications. APHIS also minimizes aerial insecticide use, where possible, however site 

conditions may dictate the need for aerial treatments. APHIS minimizes use of liquid carbaryl 

and malathion which is reflected in the historical use for both insecticides. Diflubenzuron has 

been the preferred insecticide for making Program suppression treatments. In addition APHIS 

has incorporated the use of RAATS in the Program as a means to reduce insecticide use 

providing reduced risk while meeting the goal of suppression. APHIS continues to research and 

develop new techniques for management of grasshopper and Mormon cricket populations.

Comment 38

APHIS received one comment, “While the mitigations that are identified for aquatic habitats in 

the EAs are heartening, it is unclear if the large buffers adjacent to stream habitat as agreed to 

under NMFS consultation will be implemented in Arizona, since there are no listed salmonids in 

the state.”

Buffers proposed in the NMFS consultation are for listed species under NMFS jurisdiction, of 

which there are no species in Arizona. APHIS consults locally with the FWS on applicable 

buffers to protect listed aquatic species under their jurisdiction. APHIS is also working with the 

FWS regarding a programmatic biological assessment.

In Arizona, there are no aerial treatments, only treatments using ground equipment. The APHIS 

guidelines, Appendix 1 of the EA for buffering water is adhered too. The FWS protective 

measures for Arizona T&E species is outlined in the FWS letter of concurrence in appendix 7, 

dated February 10, 2020 of the Arizona EA# AZ-20-02. The FWS letter of concurrence dated 

April 1, 2020.

Comment 39

APHIS received the following comment, “While the mitigations that are identified for aquatic 

habitats in the EAs are heartening, APHIS should include monitoring for the presence and health 

of mussels in streams that traverse or are adjacent to treatment areas as part of its monitoring 

strategy.”

APHIS conducts environmental monitoring related to Program treatments. Monitoring is 

typically done adjacent to sensitive habitats, including aquatic habitats, to determine pesticide 

residues. These data can be used to determine risk to non-target organisms based on available 

toxicity data.
Comment 40

APHIS received the following comment, “To protect freshwater mussels, APHIS should use the 

same buffers agreed to in the national consultation with NMFS to protect listed salmon to protect 

freshwater mussels.”

APHIS agrees that freshwater mussels should be protected, as well as other aquatic organisms, 

and uses ground and aerial application no treatment buffers adjacent to all aquatic habitats. In 

addition APHIS uses reduced rates of Program insecticides compared to current labeled rates. 

These mitigation measures are beyond label requirements for protection of aquatic habitats. The 

intent of these buffers is to reduce off-site drift and runoff of Program insecticides to aquatic 

habitats. No listed aquatic freshwater mussels are present in Arizona.

Comment 41

APHIS received the following comment, “The EAs do not discuss water bodies of anthropogenic 

origin, such as stock tanks or stock ponds, nor any buffers that will be observed to prevent 

pesticide overspray or drift into these habitats.”

In Arizona, all stock tanks and stock ponds are buffered for ground applications. In Arizona, 

stock ponds are considered possible critical habitat for the Chiricahua leopard frog, a T&E 

species. The same buffer is implemented for Northern Leopard frog, a species of concern in 

Arizona. These protective measures are addressed in the letters of concurrence from FWS. Draft 

EA# AZ-20-02 appendix 7.

Comment 42

APHIS received the following comment, “APHIS should recognize the potential for stock 

pond/tanks to contribute significantly to the diversity of aquatic invertebrates in rangelands.”

(See previous response). All bodies of water are buffered according to the APHIS Guidelines in 

Appendix 1 of Draft EA# AZ-20-01 and AZ-20-02.

Comment 43

APHIS received the following comment, “APHIS should identify and map all stock tanks/ponds 

and specify a buffer around stock ponds/tanks from chemical treatment at least equivalent to that 

specified for wetlands, in order to protect aquatic diversity.”

All bodies of water are buffered according to APHIS Guidelines in Appendix 1 of EA. In 

Arizona, a map of all stock tanks is used in the field during delimiting surveys and treatment 

planning. Tribal stock tank maps are provided to APHIS but are not to the public. Tribal maps 

can be provided from the individual Tribal Nations.

Comment 44

APHIS received one comment, “APHIS’ reactive strategy includes no mention of what is most 

sorely needed: cooperation and planning with land managers to take appropriate steps to prevent 

the types of grasshopper and cricket outbreaks that are now dealt with by chemical controls.”
APHIS is not a land management agency, but encourages IPM through past and current 

research and will continue to do so.

APHIS supports the use of IPM in the management of grasshoppers and Mormon Crickets. 

APHIS provides technical assistance to Federal, Tribal, State and private land managers 

including the use of IPM. However, implementation of on-the-ground IPM activities is limited to 

land management agencies and Tribes, as well as private land owners. In addition, APHIS’ 

authority under the Plant Protection Act is to treat Federal, State and private lands for 

grasshoppers and Mormon cricket populations. APHIS’ technical assistance occurs under each 

of the three alternatives proposed in the EIS.

In addition to providing technical assistance, APHIS completed the Grasshopper Integrated Pest 

Management (GIPM) project, which is discussed in more detail on page 21 of this EIS. One of 

the goals of the GIPM is to develop new methods of suppressing grasshopper and Mormon 

cricket populations that will reduce non-target effects. RAATs are one of the methods that has 

been developed to reduce the amount of pesticide used in suppression activities, and is a 

component of IPM. APHIS continues to evaluate new suppression tools and methods for 

grasshopper and Mormon cricket populations, including biological control, and as stated in the 

EIS, will implement those methods once proven effective and approved for use in the United 

States.

Comment 45

APHIS received one comment: “Emphasizing cultural techniques through appropriate grazing 

management could help to minimize pesticide application and allow natural enemies to regulate 

grasshopper and Mormon cricket populations to the greatest extent possible. While more 

research is needed to develop species- and region-specific management treatments that use 

alternatives to pesticides (Vermeire et al. 2004), there is likely enough data to employ cultural 

techniques now.”

APHIS supports the use of IPM in the management of grasshoppers and Mormon Crickets. 

APHIS provides technical assistance to Federal, Tribal, State and private land managers 

including the use of IPM, including cultural techniques. However, implementation of on-theground IPM activities is limited to land management agencies and Tribes, as well as private land 

owners. In addition, APHIS’ authority under the Plant Protection Act is to treat Federal, State 

and private lands for grasshoppers and Mormon cricket populations.

Comment 46

APHIS received one comment that, “APHIS must elevate the expectation of preventative 

approaches in its cooperative agreements with other land management agencies. APHIS can 

collaborate with agencies (such as the Natural Resource Conservation Service (NRCS), the Farm 

Service Agency (FSA), and State Extension program) to facilitate discussion and disseminate 

information to ranchers about preventative measures that can be taken and alternatives to 

pesticide use.”

APHIS supports the use of IPM in the management of grasshoppers and Mormon Crickets. 

APHIS provides technical assistance to Federal, Tribal, State and private land managers 
including the use of IPM, including cultural techniques. However, implementation of on-theground IPM activities is limited to land management agencies and Tribes, as well as private land 

owners. In addition, APHIS’ authority under the Plant Protection Act is to treat Federal, State 

and private lands for grasshoppers and Mormon cricket populations.

APHIS has maintained cooperative relationships with state and federal land managers as well as 

private landowners and Indian tribes for decades. Those relationships have allowed APHIS to 

provide consistent and continual recommendations on land management practices designed 

to mitigate the damage from orthopteran infestations.

Comment 47

APHIS received on comment that, “APHIS and/or collaborating agencies should investigate and 

implement opportunities to incentivize healthy range management practices.”

As part of its ongoing IPM strategy to manage grasshoppers and Mormon cricket outbreaks, 

APHIS collaborates with scientists and land managers focused on rangeland health.

Comment 48

APHIS received one comment that, “APHIS and its partners should be approaching the problem 

by keeping a focus on the potential to reduce grasshopper carrying capacity by making the 

rangeland environment less hospitable for the pests. APHIS must not take a limited view of its 

role and responsibilities, and should utilize any available mechanism to require land management 

agencies to diminish the severity, frequency and duration of grasshopper outbreaks by utilizing 

cultural management actions. Memoranda of Understanding (MOUs) should be examined and 

updated to ensure that land management agencies are accountable in utilizing cultural techniques 

to diminish the carrying capacity of pest species.

APHIS supports the use of IPM in the management of grasshoppers and Mormon Crickets. 

APHIS provides technical assistance to Federal, Tribal, State and private land managers 

including the use of IPM. However, implementation of on-the-ground IPM activities is limited to 

land management agencies and Tribes, as well as private land owners. In addition, APHIS’ 

authority under the Plant Protection Act is to treat Federal, State and private lands for 

grasshoppers and Mormon cricket populations.

Comment 49

APHIS received a comment, “Longer-term strategic thinking should include:

●Prevent conditions that allow pest populations to survive and reproduce.

● Employ diverse management techniques (e.g., biological, physical, and cultural).

● Select pesticides to minimize risks to nontarget organisms.

● Implement frequent and intense monitoring to identify populations that can be controlled with 

small ground-based pesticide application equipment.

● Monitor sites before and after application of any insecticide to determine the efficacy of the 

pest management technique as well as if there is an impact on water quality or non-target 

species.”
APHIS currently monitors for grasshopper and Mormon cricket populations. These measures 

are employed to allow APHIS to respond with treatment, where warranted, treating the smallest 

area possible and if practical using ground-based equipment. APHIS, due to its monitoring 

efforts, has been able to rely on diflubenzuron as the primary insecticide used in the Program.

Diflubenzuron is a more selective insecticide compared to carbaryl and malathion posing less 

risk to nontarget organisms. APHIS also uses environmental monitoring to assess application 

success and to determine if Program insecticides are reaching sensitive habitats, including 

aquatic habitats. APHIS supports the use of IPM in the management of grasshoppers and 

Mormon Crickets. APHIS provides technical assistance to Federal, Tribal, State and private 

land managers including the use of IPM. However, implementation of on-the-ground IPM 

activities is limited to land management agencies and Tribes, as well as private land owners. In 

addition, APHIS’ authority under the Plant Protection Act is to treat Federal, State and private 

lands for grasshoppers and Mormon cricket populations. APHIS continues to research and 

develop new methods for assessing and controlling grasshopper and Mormon cricket 

populations that can be incorporated into IPM practices. 

Comment 50

APHIS received one comment that, “The EAs do not make mention of any specific protections to 

be accorded to special status lands such as Wilderness areas, Wilderness study areas, Research 

Natural Areas, National Wildlife Refuges, and designated or proposed Areas of Critical 

Environmental Concern. These special status areas have been designated for specific purposes 

and generally discourage human intervention with the natural ecosystem. Grasshopper 

suppression should not be undertaken in such areas.”

APHIS does not make treatments on lands of special status without a request from that agency 

and an evaluation of the whether treatments are necessary. Additional protection measures for 

these types of lands are established by the agency requesting treatment and are followed by 

APHIS.

Comment 51

APHIS received the following comment regarding, “We appreciate that public notice of this sitespecific EA and its comment period was posted at the APHIS website. It does not appear to have 

been the practice to post the Draft EAs in the last several years, but limiting public notice is 

contrary to the spirit of the NEPA process. Grasshopper suppression efforts are of more than 

local concern and as federal actions, should be noticed properly, i.e. beyond local stakeholder 

audiences, local newspapers, etc. We recommend that, in the future, notice of open public 

comment periods for all site-specific EAs for grasshopper suppression be posted in the Federal 

Register, and documents made available for review at regulations.gov and at the APHIS 

grasshopper website.”

Public involvement under the CEQ Regulations for Implementing the Procedural Provisions of 

NEPA distinguishes federal actions with effects of national concern from those with effects 

primarily of local concern (40 CFR 1506.6). Our EIS process for the grasshopper and Mormon 

cricket suppression program was published in the Federal Register (APHIS-2016-0045), and met 

all applicable notice and comment requirements for a federal action with effects of national 

concern. This process provided individuals and national groups the ability to participate in the 
development of alternatives and provide comment. Our subsequent state-based actions have the 

potential for effects of local concern, and we publish them according to the provisions that apply 

to federal actions with effects primarily of local concern. This includes the USDA APHIS NEPA 

Implementation Procedures, which allows for EAs and FONSIs where the effects of an action are 

primarily of regional or local concern to normally provide publication in a local or area 

newspaper of general circulation (7 CFR 372.7(b)(3)). These publications provide potentially 

locally-affected individuals an additional opportunity to provide input into the decision-making 

process. Some states also provide additional opportunities for local public involvement, such as 

public meetings.

Comment 52

APHIS received the following comments, “on April 15, 2020, the day these comments were due, 

webpage stated that there were no draft EAs available,1 precluding the public’s ability to provide 

detailed comments on the very day they are due.” “On the due date for public comments on these 

EAs, April 14, 2020, the EAs are not available online.” “If for no other reason than this, these 

EAs cannot be lawfully finalized and implemented without a new comment period in which the 

public is notified, given the deadline and contact information for submission, provided access to 

the EAs through the close of the comment deadline, and then kept up beyond the close of the 

comment period so that the public may view the documents that the agencies have produced 

whenever they wish to do so.” 

The Arizona EA’s were added to the website on March 5, 2020 and removed unintentionally on 

the evening of April 14, 2020. The EA was still available from the PPQ contacts and comments 

were accepted up to and after the 30-day comment period, which ended on April 15, 2020. In an 

attempt to be more transparent, APHIS has placed all EA’s on its website for the public access. 

In addition, when an interested party asks to be informed APHIS ensures their contact 

information is added to the list of interested stakeholders. This year, as in the past, each local 

office works to inform interested parties of the availability of an EA for comment. A contact from 

the Center for Biodiversity has been added to the list of interested parties to receive notice that 

the EA documents are available for comment. Any omission of an interested party is not 

intentional.

Comment 53

APHIS received the following comments, “The Draft Environmental Assessments Frustrate 

Public Participation.” “APHIS frustrated public participation by failing to inform interested 

parties of the existence of the EAs.”

“Scoping” is the process APHIS uses through which the agency and the public identify 

alternatives and issues to be considered during the development of a grasshopper or Mormon 

cricket suppression program. Scoping was helpful in the preparation of the draft Environmental 

Assessments (EAs). The process can occur formally and informally through meetings, 

conversations, or written comments from individuals and groups.

Prior to the treatment season, APHIS conducted meetings or provided guidance for public 

participation in the decision making process. In addition, APHIS notified Federal, State and 
Tribal land managers and private landowners of the potential for grasshopper and Mormon 

cricket outbreaks on their lands.

In Arizona, prior to treatment season, letters of request from land managers were 

received. These include letters dated January 28, 2020 and a local MOU between Tribal 

Nations and APHIS with 5 year request for services dated March 13, 2019 and expiring 

on December 2024. Public meetings were held March 10, 2020 to discuss the Draft EA. 

Affidavits of Publication were made for the State of Arizona, Graham County dated March 11, 

2020, Gila County dated March 11, 2020, Coconino County dated March 11, 2020, and the State 

of Utah, Washington County, dated March 11, 2020. The public comment period opened March 

11, 2020 and expired April 15, 2020. A report of grasshopper survey season and treatments, 

if conducted are summarized in annual report that is provided to land managers and/or cattle

associations.

Comment 54

APHIS received the following comment, “APHIS did not providing information for the 

submission of public comments including where and when to submit comments by.”

APHIS works to inform all interested parties about draft EA’s for comment. When an interested 

party asks to be informed, APHIS ensures contact information is added to the list of interested 

stakeholders. Each local office works to inform interested parties of the availability of an EA for 

comment. Any omission of an interested party is not intentional.

The four Affidavits of Publication stated the website and address for EA documents and where to 

send comments and listed the closing date of April 15, 2020.

Comment 55

APHIS received the following comments, “APHIS limited public notice to local papers.” “This 

local notice is insufficient as it excludes countless other interested parties.”

Public involvement under the CEQ Regulations for Implementing the Procedural Provisions of 

NEPA distinguishes federal actions with effects of national concern from those with effects 

primarily of local concern (40 CFR 1506.6). Our EIS process for the GMC program was 

published in the Federal Register (APHIS-2016-0045), and met all applicable notice and 

comment requirements for a federal action with effects of national concern. This process 

provided individuals and national groups the ability to participate in the development of 

alternatives and provide comment. Our subsequent state-based actions have the potential for 

effects of local concern, and we publish them according to the provisions that apply to federal 

actions with effects primarily of local concern. This includes the USDA APHIS NEPA 

Implementation Procedures, which allows for EAs and FONSIs where the effects of an action are 

primarily of regional or local concern to normally provide publication in a local or area 

newspaper of general circulation (7 CFR 372.7(b)(3)). These publications provide potentially 

locally-affected individuals an additional opportunity to provide input into the decision-making 

process. Some states also provide additional opportunities for local public involvement, such as 

public meetings.
In Arizona, prior to treatment season, letters of request from land managers were 

received. These include letters dated January 28, 2020 and a local MOU between Tribal 

Nations and APHIS with 5 year request for services dated March 13, 2019 and expiring 

on December 2024. Public meetings were held March 10, 2020 to discuss the Draft EA.

Affidavits of Publication were made for the State of Arizona, Graham County dated March 11, 

2020, Gila County dated March 11, 2020, Coconino County dated March 11, 2020 and the State 

of Utah, Washington County, dated March 11, 2020. The public comment period opened March 

11, 2020 and expired April 15, 2020.

Comment 56

APHIS received the following comments, “APHIS provided a short public comment period 

during this COVID-19 pandemic.” “The 30 day comment deadline for the Draft EAs is wholly 

inappropriate during the current COVID-19 pandemic, where both staff and members of the 

concerned public have limited capacity, given the challenges associated with a global pandemic 

including but not limited to increased childcare demands, illness, etc.”

The comment period was in accordance with CEQ regulations, 40 C.F.R. § 1501.4(e) (2), in 

determining whether to prepare an environmental impact statement the Federal agency shall: (e) 

Prepare a finding of no significant impact, if the agency determines on the basis of the 

environmental assessment not to prepare a statement. (2) In certain limited circumstances, which 

the agency may cover in its procedures under § 1507.3, the agency shall make the finding of no 

significant impact available for public review (including State and area-wide clearinghouses) for 

30 days before the agency makes its final determination whether to prepare an environmental 

impact statement and before the action may begin. CEQ guidance also notes: When preparing 

an EA, the agency has discretion as to the level of public involvement. The CEQ regulations state 

that the agency shall involve environmental agencies, applicants, and the public, to the extent 

practicable, in preparing EAs. Sometimes agencies will choose to mirror the scoping and public 

comment periods that are found in the EIS process. In other situations, agencies make the EA 

and a draft FONSI available to interested members of the public. APHIS would have 

considered extending the comment period if there had been a reason to believe that additional 

substantive issues remained, or that the pandemic itself created new issues.

In Arizona, public meetings were scheduled in February and held March 10, 2020. The World 

Health Organization did not declare COVID-19 a pandemic until March 11, 2020. The CDC 

provided guidance for meetings of more than 50 people on March 15, 2020. Public interaction in 

Arizona occurred well before stay at home order issued by the Arizona governor on March 30, 

2020. Affidavits of Publication were made for the State of Arizona, Graham County dated 

March 11, 2020, Gila County dated March 11, 2020, Coconino County dated March 11, 

2020 and the State of Utah, Washington County, dated March 11, 2020. The public comment 

period opened March 11, 2020 and expired April 15, 2020.

Comment 57

APHIS received the following comment, “the proposal in question is controversial and deals 

with issues of significant public interest.”
APHIS is not aware of any controversy in the program. Every year APHIS works with local 

stakeholders to gather information and discuss the grasshopper program. The grasshopper 

program requires a written request to treat on any land and discussions with the land owner or 

manager determine the course of the final action. APHIS acts in partnership with stakeholders 

through agreements and Memorandum of Understanding on all activities in the program.

In Arizona, Hot Spot Treatments have been conducted to suppress grasshopper outbreaks since 

2009. The effects of these outbreaks are localized to several grazing allotments in Arizona. The 

land managers, ranchers, and cattle associations request APHIS services annually. Public 

meetings are conducted annually. There have been minimal comments from the public in the 

past regarding various issues related to the Program.

Comment 58

APHIS received the following comment, “The Draft EAs also limit public participation by 

failing to provide contact information for the submission of written or electronic comments.”

The local offices send out public notices to a list of stakeholders that they have collected over the 

years and also announced the open comment period in the local media. Those notices have the 

link for the EA’s and the point of contact. In an attempt to be more transparent APHIS 

has also placed Program EA’s on to the APHIS website for the public to access. When an 

interested party asks to be informed, APHIS ensures their contact information is added to the list 

of interested stakeholders. Each local office works to inform interested parties of the availability 

of an EA for comment. Any omission of an interested party is not intentional. 

Contact information for the Arizona EA is on the cover page for each EA. Also on page 7 of the 

EA, the contact address of the Arizona Field Operations State office is listed for copies of all 

documentation. The four Affidavits of Publication state the website and address for obtaining 

the EAs and where to send comments.

Comment 59

APHIS received the following comment, “Nowhere on the webpage for the Draft Environmental 

Assessment Rangeland Grasshopper and Mormon Cricket Suppression Program is there any 

information on where to submit comments.”

The local offices send out public notice to a list of stakeholders that they have collected over the 

years and they also announce the open comment period in the local media. Those notices have 

the link for the EA’s for comment and the point of contact. In an attempt to be more 

transparent APHIS has also placed Program EA’s on its website. When an interested party asks 

to be informed, APHIS ensures their contact information is added to the list of interested 

stakeholders. Each local office works to inform interested parties of the availability of an EA for 

comment. Any omission of an interested party is not intentional. For Arizona (See Previous 

Response).
Comment 60

APHIS received the following comment, “Staff for USDA-APHIS that have been involved with 

the environmental review for this program were unable to readily provide information for the 

submission of public comment.”

The local offices send out public notice to a list of stakeholders that they have collected over the 

years and they also announce the open comment period in the local media. Those notices have 

the link for the EA’s for comment and the point of contact. In an attempt to be more 

transparent, we have put all of our EA’s on to the website for people to access. When an 

interested party asks to be informed APHIS ensures their contact information is added to the list 

of interested stakeholders. Each local office works to inform interested parties of the availability 

of an EA for comment. Any omission of an interested party is not intentional. Contact 

information for Arizona EA’s is on the cover page of the Draft EA’s. Also on page 7 of the EA 

the contact address of the Arizona Field Operations State office is listed for copies of all 

documentation. The four Affidavits of Publication state the website and address for obtaining 

the EAs and where to send comments.

APHIS is not aware of the direct personnel communication cited by the commenter. APHIS

personnel are engaged in a wide variety of activities to protect American agriculture and not 

every staff member is completely informed about the details of the Grasshopper Program NEPA 

compliance procedures.

Comment 61

APHIS received the following comment, “there is no information on when the comment period 

opened or closed on the EAs provided on the webpage.”

The local offices send out public notice to a list of stakeholders that they have collected over the 

years and they also announce the open comment period in the local media. Those notices have 

the link for the EA’s for comment and the point of contact. In an attempt to be more 

transparent, we have put all of our EA’s on to the website for people to access. When an 

interested party asks to be informed, APHIS ensures there contact information is added to the list 

of interested stakeholders. Each local office works to inform interested parties of the availability 

of an EA for comment. Any omission of an interested party is not intentional.

Contact information for Arizona EA’s is on the cover page of the Draft EA# AZ-20-01 and AZ20-02. Also on page 7 of the EA the contact address of the Arizona Field Operations State office 

is listed for copies of all documentation. The four Affidavits of Publication clearly stated the 

website and Address for EA documents and where to send comments and the closing date of 

April 15, 2020.

Public meetings were held March 10, 2020 to discuss Draft EA. Affidavits of Publication were 

made for the State of Arizona, Graham County dated March 11, 2020, Gila County dated March 

11, 2020, Coconino County dated March 11, 2020 and the State of Utah, Washington County, 

dated March 11, 2020. The public comment period opened March 11, 2020 and expired April 

15, 2020.
Comment 62

APHIS received the following comment, “With the EAs dated March 3, 2020 and March 4, 

2020, respectively, a reasonable person could have easily concluded that a 30 day comment 

period ended on April 3, 2020 or April 4, 2020, respectively, rather than the April 15, 2020 

comment deadline.”

See previous response.

Comment 63

APHIS received the following comment, “APHIS has failed to comport with NEPA’s threshold 

requirements.”

APHIS did not fail to perform NEPA’s threshold requirements for public outreach and 

engagement, but rather exceeded them. See previous comments concerning how APHIS informed 

interested parties of the availability of EAs for public comment, including public meetings, where 

to send comments, and the closing date for the comment period. See response to comment 53.

Comment 64

APHIS received the following comment, “The Draft EAs further limit public participation by 

failing to post notices in the Federal Register or on regulations.gov, unlike earlier versions of the 

environmental review.”

APHIS further involves the public in the scoping process by the publication of notices of 

availability for EAs and a Findings of No Significant Impact (FONSIs). When an individual State 

level EA is written, a notice is published in the legal section of the local newspaper, advertising 

the availability of the EA during an open comment period. The notices published in local 

newspapers was conducted in accordance with APHIS’ NEPA Implementation Procedures, 

372.7 (b)(3), Notification of the availability of environmental assessments and findings of no 

significant impact for proposed activities will be published in the FEDERAL REGISTER, unless 

it is determined that the effects of the action are primarily of regional or local concern. Where 

the effects of the action are primarily of regional or local concern, notice will normally be 

provided through publication in a local or area newspaper of general circulation and/or the 

procedures implementing Executive Order 12372, “Intergovernmental Review of Federal

Programs.”

Public involvement under the CEQ Regulations for Implementing the Procedural Provisions of 

NEPA distinguishes federal actions with effects of national concern from those with effects 

primarily of local concern (40 CFR 1506.6). Our EIS process for the GMC program was 

published in the Federal Register (APHIS-2016-0045), and met all applicable notice and 

comment requirements for a federal action with effects of national concern. This process 

provided individuals and national groups the ability to participate in the development of 

alternatives and provide comment. Our subsequent state-based actions have the potential for 

effects of local concern, and we publish them according to the provisions that apply to federal 

actions with effects primarily of local concern. This includes the USDA APHIS NEPA 

Implementation Procedures, which allows for EAs and FONSIs where the effects of an action are 

primarily of regional or local concern to normally provide publication in a local or area 
newspaper of general circulation (7 CFR 372.7(b)(3)). These publications provide potentially 

locally-affected individuals an additional opportunity to provide input into the decision-making 

process. Some states also provide additional opportunities for local public involvement, such as 

public meetings.

In Arizona, Draft EA’s are emailed upon request from public, stakeholder, etc. Tribal 

stakeholder’s copies of EA’s are delivered in person annually. Comments in past years have 

come from Tribal biologists, soil scientists, natural resource specialists and the general public. 

Comment 65

APHIS received the following comment, “[The Center for Biological Diversity] have 

been informed that there was notice in local newspapers. This local notice is insufficient as it 

excludes countless other interested parties.”

See previous response

Comment 66

APHIS received the following comment, “APHIS has failed to meet NEPAs requirements for 

public involvement in these EAs.”

APHIS also notes CEQ guidance for public involvement in the NEPA process of agencies, “A 

Citizen’s 12 Guide to the NEPA” states: “When preparing an EA, the agency has discretion as 

to the level of public involvement. The CEQ regulations state that the agency shall involve 

environmental agencies, applicants, and the public, to the extent practicable, in preparing EAs. 

Sometimes agencies will choose to mirror the scoping and public comment periods that are 

found in the EIS process. In other situations, agencies make the EA and a draft FONSI available 

to interested members of the public”.

Contact information for Arizona EA’s is on the cover page of the Draft EA’s. Also on page 7 of 

the EA the contact address of the Arizona Field Operations State office is listed for copies of all 

documentation. The four Affidavits of Publication state the website and address for the EAs and 

where to send comments prior to the closing date of April 15, 2020.

Public meetings were held March 10, 2020 to discuss the Draft EA. Affidavits of Publication

were made for the State of Arizona, Graham County dated March 11, 2020, Gila County dated 

March 11, 2020, Coconino County dated March 11, 2020 and the State of Utah, Washington 

County, dated March 11, 2020. The public comment period opened March 11, 2020 and expired 

April 15, 2020.

Comment 67

APHIS received the following comment, “the range of alternatives offered by APHIS is woefully 

inadequate.”

APHIS structured and analyzed the risk of the substantial program alternatives available to the 

agency. Alternatives, including those excluded from further analysis, were discussed in the final 

EIS.
Comment 68

APHIS received the following comment, “[The alternatives] are, “No Action,” “Insecticide 

Applications at Conventional Rates or Reduced Agent Area Treatments with Adaptive 

Management Strategy” (preferred alternative) and “Experimental Treatments Alternative. While 

the RAATs are an improvement over conventional approval rates, this alternative should actually 

be two, one, Insecticide Applications at Conventional Rates and two, Reduced Agent Area 

Treatments with Adaptive Management Strategy. Lumping the two together means that 

supporting this alternative could mean pesticide application at conventional rates without 

RAATs. APHIS must break these into different alternatives.”

The EA states “Under Alternative A, the No Action alternative, APHIS would not conduct a 

program to suppress grasshopper infestations. Under this alternative, APHIS may opt to provide 

limited technical assistance, but any suppression program would be implemented by a Federal 

land management agency, a State agriculture department, a local government, or a private 

group or individual.”

Under Alternative B, the Preferred Alternative, APHIS would manage a grasshopper treatment 

program using potentially any of pesticides and application methods described in the EA 

Alternative B to suppress outbreaks. The grouping of conventional methods and pesticide rates 

with the more commonly used RAATs procedures reflects the variety of approaches that the 

agency may need depending on treatment specific circumstances.

Comment 69

APHIS received the following comment, “APHIS does not include an alternative that utilizes 

Integrated Pest Management.”

APHIS technical guidance is part of each alternative proposed, and is not unique to any one 

alternative. An example of APHIS technical guidance is the agency’s work on integrated pest 

management (IPM) for the grasshopper program. IPM for grasshoppers includes biological 

control, chemical control, rangeland and population dynamics, and decision support tools.

APHIS has funded the investigation of various integrated pest management (IPM) strategies for 

the grasshopper program. Congress established the Grasshopper Integrated Pest Management 

(GIPM) to study the feasibility of using IPM for managing grasshoppers.

The major objectives of the APHIS GIPM program were to: 1) manage grasshopper populations 

in study areas, 2) compare the effectiveness of an IPM program for rangeland grasshoppers with 

the effectiveness of a standard chemical control program on a regional scale, 3) determine the 

effectiveness of early sampling in detecting developing grasshopper infestations, 4) quantify 

short- and long-term responses of grasshopper populations to treatments, and 5) develop and 

evaluate new grasshopper suppression techniques that have minimal effects on non-target 

species (Quinn, 2000). The results for the GIPM program have been provided to managers of 

public and private rangeland including ways to manage grasshopper populations in the longterm, such as livestock grazing methods and cultural control by farmers.
APHIS issued the GIPM User Handbook describing biological control, chemical control, 

environmental monitoring and evaluating, modeling and population dynamics, rangeland 

management, decision support tools, and future directions.

Federal and State land management agencies, State agriculture departments, and private groups 

or individuals may carry out a variety of preventative IPM strategies that may reduce the 

potential for grasshopper outbreaks. Some of these activities include grazing management 

practices, cultural and mechanical methods, and prescribe-burning of rangeland areas. These 

techniques have been tried with varying success in rangeland management, and some have been 

associated with the prevention, control, or suppression of harmful grasshopper populations on 

rangeland.

Regardless of the various IPM strategies taken, the primary focus of the risk analysis contained 

in the EAs is on the potential impacts from chemical treatments needed during an outbreak of 

economic importance. While APHIS provides technical expertise regarding grasshopper 

management actions, the responsibility for implementing most land management practices lies 

with other Federal (i.e., BIA, BLM, and USDA’s FS), State, and private land managers.

The final EA will be updated to reflect APHIS support for IPM strategies in the grasshopper and 

Mormon cricket suppression program.

Comment 70

APHIS received the following comment, “Given that much of APHIS’s work on grasshopper and 

Mormon cricket suppression is on lands managed by DOI or USDA or adjacent to federal public 

lands in Arizona, it only makes sense that it would conform to their IPM mandates in these 

EAs.” 

See previous response. APHIS supports the use of IPM to prevent grasshopper outbreaks on or 

near Federal lands. These actions are and should continue to be considered by agencies as part 

of proper land management. APHIS treatments are a component of the IPM strategies that may 

be employed by Federal land management agencies. APHIS also adheres to any restrictions 

proposed by Federal or State land management agencies that may be part of their IPM 

strategies. 

Comment 71

APHIS received the following comment, “APHIS must adopt an alternative that harmonizes its 

mandates in regard to grasshoppers and Mormon crickets with the IPM mandates of the federal 

lands that it operates on.”

See previous response. A Memorandum of Understanding between land management agencies, 

i.e., the Department of Interior’s Bureau of Indian Affairs and Bureau of Land Management, and 

USDA’s Forest Service, indicates that while APHIS provides technical expertise, namely advice, 

regarding grasshopper management actions, the responsibility for implementing most land 

management practices, including IPM measures, lies with other Federal (i.e., BIA, BLM, and 

USDA’s FS), State, and private land managers (page 32 of the 2019 EIS).
Comment 72

APHIS received the following comment, “APHIS must enlist IPM experts to craft an alternative 

that is land-use and pest-specific, using the minimum level of pest suppression necessary, relying 

on prevention, avoidance, monitoring, and suppression techniques in order to decrease pest 

pressure with the least harmful controls possible.”

See comment 69

Comment 73

APHIS received the following comment, “APHIS must conduct an adequate analysis of human 

health effects.”

APHIS prepared and published separate Final Human Health and Ecological Risk Assessments 

for all the pesticides used by the Grasshopper Programs (November 2019).

Adherence to label requirements and additional Program measures designed to reduce exposure 

to workers (e.g., PPE requirements include long-sleeved shirt and long pants and shoes plus 

socks) and the public (e.g., mitigations to protect water sources, mitigations to limit spray drift, 

and restricted-entry intervals) result in low health risk to all human population segments.

Comment 74

APHIS received the following comment, “there is no description of how APHIS plans to identify 

or contact these individuals in order to advise them to avoid treatment areas.”

In areas considered for treatment, State-registered beekeepers and organic producers shall be 

notified in advance of proposed treatments. APHIS will notify residents within treatment areas, 

or their designated representatives, prior to proposed operations, and advise them of the control 

method to be used, proposed method of application, and precautions to be taken.

Comment 75

APHIS received the following comment, “APHIS’s failure conduct any analysis of their impacts 

to human health is a far cry from the level of analysis demanded by NEPA and basic due care for 

public health.” 

See responses to comment 73. APHIS prepared and published separate Final Human Health and 

Ecological Risk Assessments for all the pesticides used by the Grasshopper Programs 

(November 2019). These documents were incorporated by reference into the draft EA.

Comment 76

APHIS received the following comment, “APHIS fails to look at the effects of the proposed 

action on migratory birds.”

Executive Order 13186 directs Federal agencies taking actions with a measurable negative 

effect on migratory bird populations to develop and implement a Memorandum of Understanding 

with the USFWS that promotes the conservation of migratory bird populations. On August 2, 
2012, a Memorandum of Understanding between APHIS and the USFWS was signed to facilitate 

the implementation of this Executive Order.

Specifically to the grasshopper and Mormon cricket program, APHIS evaluated potential 

impacts to birds in the final EIS and associated human health and ecological risk assessments.

These documents are incorporated by reference into the final EA.

Comment 77

APHIS received the following comment, “APHIS needs to take a hard look at the impacts of the 

proposed action, including direct and indirect effects.”

The EA incorporated the analysis from the EIS and associated human health and ecological risk 

assessments into the analysis. The EIS, and in particular, the risk assessments evaluated 

potential indirect effects to non-target organisms, relying on available toxicity data and 

estimates of risk. 

Comment 78

APHIS received the following comment, “A direct effect of not spraying insecticides is abundant 

food for migratory birds. Conversely, a direct effect of spraying is reduced abundance of food for 

insectivorous migratory birds. Another potential direct effect of insecticide spraying is 

poisoning. An example of an indirect effect is the cumulative effect of continuous low level 

pesticide exposure from numerous sites over many years. APHIS must take a hard look at all 

these impacts”.

APHIS prepared and published separate Final Human Health and Ecological Risk Assessments 

for all the pesticides used by the Grasshopper Programs (November 2019). The risk assessments 

discuss the risk to birds for each program insecticide. Available laboratory and field effects data 

were used to evaluate risks to birds through direct exposure as well as indirect effects that could 

result from the loss of prey items such as terrestrial arthropods.

Comment 79

APHIS received the following comment, “APHIS’s handling of impacts to non-target species 

and species of concern wholly fails to meet NEPA’s requirement that the agency take a hard look 

at the impacts of its proposed action.”

APHIS prepared and published separate Final Human Health and Ecological Risk Assessments 

for all the pesticides used by the grasshopper and Mormon cricket suppression 

program (November 2019). The EIS and risk assessments evaluated available effects data and 

risk to non-target species. These documents are incorporated by reference into the final EA. The 

risk assessments provided the basis for summary statements in the EA that is tiered to the EIS.

Comment 80

APHIS received the following comment, the EA cannot be finalized until APHIS actually takes a 

hard look at the impacts on non-target and species of concern.
APHIS prepared and published separate Final Human Health and Ecological Risk Assessments 

for all the pesticides used by the grasshopper and Mormon cricket suppression program 

(November 2019). The EIS and risk assessments evaluated available effects data and risk to nontarget species. These documents are incorporated by reference into the final EA. The risk 

assessments provided the basis for summary statements in the EA that is tiered to the EIS.

Under FWS Section 7 Act there is no requirement to consult on sensitive species. (See FWS letter 

of concurrence dated February 10, 2020 in Arizona Draft EA# AZ-20-02 Appendix 7, first 

paragraph last sentence). This in regards to APHIS protective measures for the Northern 

Leopard Frog a species of concern in Arizona. However, in Arizona when there is concern by 

land management agencies, federal, state, etc.; APHIS has implemented protective measures for 

species of concern which may be closely related to a T&E species. This is a cooperative effort by 

APHIS between FWS, Tribal Nations, Arizona Game & Fish or the Requesting Land 

Management agency.

Comment 81

APHIS received the following comment, “APHIS doesn’t even consider many sensitive or 

culturally important species. For example, monarch butterflies fly through Arizona.”

APHIS prepared and published separate Final Human Health and Ecological Risk Assessments 

for all the pesticides used by the Grasshopper Programs (November 2019). The risk assessments 

and EIS considered available field and laboratory data regarding impacts to Lepidoptera, 

including moths and butterflies. 

Comment 82

APHIS received the following comment, “APHIS also doesn’t consider the impacts of spraying 

on the incredible diversity of native bee species that reside in Arizona, including many that are 

exceedingly rare, existing nowhere else on earth.”

APHIS works with Tribal, Federal and State land managers and their local biologists, natural 

resource specialists, and range conservationists to implement measures that reduce risks of 

Program treatments to native bees. These measures may include reduced insecticide applications 

associated with RAATS, avoidance measures and use of carbaryl bait, where applicable.

APHIS also prepared and published separate Final Human Health and Ecological Risk 

Assessments for all the pesticides used by the Grasshopper Programs (November 2019). The risk 

assessments summarized available effects data for nontarget species including pollinators.

Comment 83

APHIS received the following comment, “The EAs have not adequately analyzed the cumulative 

impacts of the program with other governmental or private entity actions.”

APHIS discussed the potential of overlapping chemical treatments in the areas where outbreaks 

of grasshoppers have occurred or could occur in the future in the cumulative impacts section of 

the draft EIS, from page 79 to 83. It is unlikely there would be significant overlap between 

APHIS programs and the grasshopper program and coordinated treatments would mitigate 

impacts if there is ever overlap; current label and mitigations minimize significant exposure of 
soil, water, and air to Program insecticides; grasshopper chemical treatments are not expected 

to persist or bioaccumulate in the environment; and, there is a lack of significant routes of 

exposure (page 82 to 83 of draft EIS).

We are unaware of any retreatment that would occur in an area where APHIS has conducted 

a treatment. Generally, the land that APHIS treats is a hybrid of BLM rangeland and absentee 

landowners leasing land for grazing. Private landowners do not actively manage that land 

and, therefore, are not expected to be making any other types of chemical treatments.

Although APHIS is unaware of any, BLM could potentially do herbicide treatments in areas we 

treat, but they would not treat for GHMC. The cumulative impacts section was updated in the 

final EA to reflect the potential for other land management activities.

Comment 84

APHIS received the following comment, “The EA does not take into account the background 

level of exposure to humans and animals from pesticides and other pollutant sources that exist in 

the environment from other actions or the synergistic effects of the enhanced toxicity that many 

mixtures exhibit.”

The commenter assumes that the rangeland in Arizona which is covered by the Draft EA’s AZ20-01 and AZ-20-02 has been exposed to pesticides and pollutants and that there is a synergistic 

effect which enhances toxicity to the environment. The land managers that manage the 

areas covered in the EAs, document all pesticide applications. The activities, or lack thereof, are 

discussed in the cumulative impacts section of the final EA.

Comment 85

APHIS received the following comment, “[the EA] does not account for the range of cumulative 

exposures that would be anticipated. There was no mention of widespread mosquito spraying 

that takes place in many areas.”

The Arizona Draft EA’s do not account for the commenter’s remarks due to the fact that there is 

no widespread mosquito spraying in the State of Arizona.

Comment 86

APHIS received the following comment, “as cattle are grazing these pesticides will be washed 

off their bodies or excreted through waste and contaminate surrounding land and water bodies.”

The labels for Dimilin 2L and Carbaryl 2% bait specify that there is no grazing restrictions. Any 

pesticide residues that may be present on forage in treated areas after treatment is typically 

metabolized and excreted as metabolites that have lower toxicity than the parent compound. In 

addition the low application rates employed by APHIS relative to the current maximum labelled 

rates for each Program insecticide would result in very low residues in livestock waste. 

Comment 87

APHIS received the following comment, “A substantial acreage of rangeland is adjacent to lands 

used for plant agriculture, and the EAs state that they also aim to protect these agricultural lands. 

These areas generally have a high potential for crossover contamination through drift or runoff of 
pesticides. Large quantities of pesticides, including insecticides and fungicides that may be 

synergistic with the insecticides included in the EAs, may be used on these lands. In addition, 

herbicide use on crops already significantly impacts insects by destroying habitat and food 

sources in agricultural lands”.

The comment does not specify which State’s EA’s have rangeland adjacent to agricultural land.

The areas that are proposed for treatment and addressed in EA# AZ-20-01 and AZ-20-02 are not 

adjacent to agricultural land. The nearest agricultural land addressed by AZ-20-01 is 

approximately 20 miles away from the proposed treatment area. For the AZ-20-02 EA the 

nearest agricultural land is 35 miles away.

Comment 88

APHIS received the following comment, “None of these issues were disclosed or analyzed in the 

Draft EIS and add to the already large cumulative exposures from pesticides used in 1) the boll 

weevil eradication program, 2) fruit fly cooperative eradication program, 3) the gypsy moth 

cooperative eradication program, and 4) invasive plant control”.

The commenter refers to the Draft EIS. The EIS has been finalized and the ROD has been 

signed. The final EIS does address the cumulative exposures from other APHIS programs on a 

programmatic level. The documents in question are the Draft EA’s. The programs mentioned by 

the commenter are not relevant to the Rangeland Grasshopper and Mormon Cricket Suppression 

Program in Arizona.

There is no geographical overlap in Arizona now or in the foreseeable future between pesticide 

applications of the Grasshopper Program and the pest control programs mentioned by the 

commenter.

Comment 89

APHIS received the following comment, “These cumulative exposures cannot only adversely 

affect human and environmental health but can also negatively impact biological control 

programs that try to manage insect and weed pests with natural predators”.

The Grasshopper Program personnel are also the lead biocontrol program personnel in Arizona

and are aware of the locations of biocontrol programs. All grasshopper treatments are 

coordinated with the land managers and other non-grasshopper programs are discussed if the 

land managers are concerned about an overlap with other programs. In Arizona, there never 

has been an overlap of grasshopper treatments and any biocontrol program areas. The final EA 

was updated to reflect the lack of overlap between biocontrol activities and Program treatments.

Comment 90

APHIS received the following comment, “How these pesticides act in conjunction with one 

another to additively or synergistically increase toxicity is not discussed and no mitigation 

measures were proposed. Therefore, APHIS must fully analyze the impacts from cumulative 

exposures and identify ways in which risk can be mitigated or prohibited”.
The Grasshopper Program does not apply treatments more than once per year to any rangeland 

area. Cumulative exposures from pesticides applied by external parties are not anticipated in 

most cases due to coordination between APHIS, land managers and other cooperators, on 

rangeland that may be receive grasshopper or Mormon cricket treatments. The EA details many 

procedures APHIS employs to mitigate risk.

Comment 91

APHIS received the following comment, “The project is vague and ill-defined, it improperly 

precludes the disclosure of environmental effects because the information on the project and its 

impacts is incomplete”.

The proposed Grasshopper treatment program described in the EA could occur within a specific 

area, using a limited number of insecticides and application methods. The environmental 

consequences of suppressing or not suppressing grasshopper infestations are analyzed in the EA 

and other programmatic risk analysis documents.

Comment 92

APHIS received the following comment, “APHIS’s explanation of a “level of economic 

infestation,” which is the trigger for insecticide spraying, does not give the public any sense 

whatsoever of when that threshold is met. The definition is too vague and ill-defined to meet 

NEPA’s purposes and mandates. The agency could spray with minimal infestation levels if it 

saw fit whenever it decided to do so. There must be a more concrete definition that identifies 

specific thresholds that must be met for the agency to determine an economic level of infestation 

has been met”.

APHIS utilizes and provides links to extensive resources for determining when a grasshopper 

outbreak is exceeding IPM thresholds including, “a level of economic infestation”. The Purpose 

and Needs section of the EA and supporting documents adequately define the multiple factors 

that must be evaluated before APHIS decides a treatment is necessary.

The following footnote is in the Draft EA# AZ-20-02 page 4. It was accidental omitted in the 

draft version of AZ-20-01, but will be corrected in the Final EA.

The “economic infestation level” is a measurement of the economic losses caused by a 

particular population level of grasshoppers to the infested rangeland. This value is determined 

on a case-by-case basis with knowledge of many factors including, but not limited to, the 

following: economic use of available forage or crops; grasshopper species, age, and density 

present; rangeland productivity and composition; accessibility and cost of alternative forage; 

and weather patterns. In decision-making, the level of economic infestation is balanced against 

the cost of treating to determine an “economic threshold” below which there would not be an 

overall benefit for the treatment. Short-term economic benefits accrue during the years of 

treatments, but additional long-term benefit may accrue and be considered in deciding the total 

value gained by treatment. Additional losses to rangeland habitat and cultural and personal 

values (e.g., aesthetics and cultural resources), although a part of decision-making, are not part 

of the economic values in determining the necessity of treatment.
Comment 93

APHIS received the following comment, “The EA’s description of the preferred alternative that 

includes “reduced agent area treatments” (“RAATs”) is similarly vague and ill defined”.

RAATs has long been in use, is public knowledge, and one of APHIS’s preferred IPM strategies, 

supported by decades of research. Skipping swaths are the most common RAATs choice, leaving 

50% of the treated area untreated to maximize refugia for non-target arthropods while 

simultaneously inducing target Orthoptera mortality at desired levels. RAATs are also described 

in detail in the final EIS that is incorporated by reference in the EA.

Comment 94

APHIS received the following comment, “It is unclear whether RAATs will even be used and 

how they will be used in the site specific area”.

APHIS’ preferred method of treatment is to use RAATs as a means to reduce program costs and 

potential environmental effects. However the program could decide to apply insecticides at 

conventional rates and total area coverage if a damaging grasshopper infestation warrants that 

level of suppression. These instances are rare due to monitoring and other technical assistance 

provided by APHIS. An explanation of the uncertainties involved with predicting grasshopper 

populations before they emerge is provided in section I.C. About this Process.

Comment 95

APHIS received the following comment, “APHIS could use the pesticide at 95% of the labelled 

rate and still call the application a RAAT.”

RAAT’s is defined as Reduced Agent and/or Area Treatments. The current pesticide labels for 

use in the Program do not allow applications at 95% of the labeled rate to be called RAATs.

This information was also summarized in the final EIS. EPA has approved the RAAT verbiage 

for each pesticide label. The labels clearly state which rates are allowed to meet a RAAT rate. In 

the case of Dimilin 2L label, which clearly states the application rates for RAAT’s is 0.75 - 1 

ounce per acre. “Use on rangeland only, in a RAAT’s application on early instars. A RAAT’s 

application is an IPM strategy that takes advantage of grasshopper movement and conservation 

biological control to allow Dimilin 2L to be applied on rangeland on a reduced treated area and 

at reduced rates, while sustaining acceptable control.”

The applicator can only use the RAAT’s rate of .75 or 1 ounce per acre. The label rate, if not 

using RAAT’s is 2 ounces/acre. The RAAT’s rate would be 50% of the label rate not 95% of 

labeled rate. 

In the case of using Carbaryl 5% bait the label rate is 20-40 lbs. per acre. APHIS uses the 

RAAT’s rate of 10lbs/acre. In the case of Carbaryl 2% bait, the label clearly states for ground 

applications 25 pounds/acre. It clearly states for U.S. Federal Government and State affiliated

Grasshopper/Mormon Cricket Suppression Programs using aerial applications the rate of 

application is 10 pounds/acre. So clearly the RAAT’s applications are 50% or less than the 

labeled rates.
In the case of a full coverage treatment, the total acreage is treated. In the case of reduced area 

portion of RAAT’s the treatment area would be 50% less than a full coverage treatment. The 

reduced area is achieved through alternating the treated and untreated swath widths. The 

RAAT’s application rates are described in detail in the Draft EA’s and depending on the 

pesticide used in a treatment, the label will also specify or clarify what the RAAT’s rate. The 

reduced area is achieved by skipping a treated swath. For example, if the swath width of the 

treatment equipment is 40 feet, then the treated swath would be 40 feet. Then the adjacent swath 

would be skipped or untreated. The next treated swath would then be applied. So across the 

treatment block would be treated and untreated swaths. Thus the reduced area of actual treated 

ground, instead of a conventional broadcast treatment.

The RAAT procedures used by the program are flexible to allow for a reduction of pesticide use. 

Typically the RAAT procedures will result in half the amount of pesticide being applied to a 

treatment block than conventional rates and total coverage. Program managers may reduce the 

rate at which the pesticide is sprayed from the aircraft or increase the distance between swaths 

that are sprayed based on factors specific to grasshopper populations being suppressed. It 

should be noted that APHIS average RAAT rates are lower than the labeled RAAT rates further 

reducing pesticide loading into the environment.

Comment 96

APHIS received the following comment, “The agency must give the public a more precise 

definition of when the threshold for spraying has been met (i.e. number of grasshoppers or 

crickets/acre and a full description of the economic interests at stake).”

APHIS utilizes and provides links to extensive resources for determining when a grasshopper 

outbreak is exceeding economic thresholds including, “a level of economic infestation”. The 

Purpose and Needs section of the EA and supporting documents adequately define the multiple 

factors that must be evaluated before APHIS decides a treatment is necessary. Establishing a 

treatment threshold based on the number of grasshoppers ignores a variety of factors that must 

be considered by program managers before treatments. Some examples include how voracious 

the individual species are that compose a grasshopper infestation and the hardiness of 

rangeland vegetation within a proposed treatment block. These factors are also discussed in the 

recently published final EIS and are incorporated by reference in the final EA.

Comment 97

APHIS received the following comment, “APHIS must also convey what metrics will be used to 

determine the area that will be sprayed in any given outbreak”.

The size and exact configuration of a treatment block cannot be forecast prior to the emergence 

of the grasshoppers, requests from land managers and other cooperators, and other 

environmental considerations such as buffers from water and sensitive species. The program 

procedures and mitigation measures are adequately described in the EA and supporting 

documents.

APHIS is unable to predict exactly what areas will be treated before conducting surveys and 

completing the EA. For ground applications, the terrain is key to be able to treat safely. If the 
terrain is too rough to safely drive a UTV, then the area is not treated even though other factors 

warrant a treatment. There are many variables taken into account before an area is treated.

Another factor that must be considered is the movement of populations. If for any number of 

reasons, a treatment can be delayed there is a risk that, depending on species, the boundaries 

will have to be readjusted to account for the movement of populations.

For example, it is documented that Melanoplus sanguinipes, the Migratory Grasshopper can 

swarm and fly up to 5-10 miles normally. The longest migrations recorded in 1938 were made by 

swarms that traveled from northeastern South Dakota to the southwestern corner of 

Saskatchewan, a distance of 575 miles (Pfadt, 1994). This is why it is critical to have a rapid 

response to outbreaks. Population dynamics of grasshoppers and Mormon crickets are fluid and 

responses have to be adaptable to the most current assessments to ensure successful suppression 

treatments while minimizing environmental impacts.

Comment 98

APHIS received the following comment, “The agency must accurately and comprehensively 

disclose and analyze the range of rare, sensitive, threatened, and endangered species, ecological 

areas, communities, Native American gathering grounds and sensitive receptors that could 

potentially be significantly affected by the proposed project” Without this baseline data the EA 

cannot disclose the environmental effects of the project”.

In Arizona, Native American gatherings are considered by some Tribes as Holy 

Ground and is only made available to APHIS when necessary. This will not be published or 

disclosed to the public as per Local Tribal Agreements. It is addressed in general terms when 

published in the EA. The more specific details are addressed with each individual Tribal Nation 

during the Tribal meetings. T&E species are analyzed during the FWS Section 7 

consultations. APHIS adheres to protective measures which have been agreed upon with FWS 

and addressed in the letters of concurrence. See Draft EA# AZ-20-02 appendix 7 FWS Letter of 

Concurrence dated February 10, 2020. APHIS also works with Federal and State land 

managing agencies to protect other sensitive resources managed on their lands.

APHIS adequately summarized available data for current baseline conditions in the draft 

EA. This includes cultural resources as well as the potential for any overlap of federally listed 

species with the proposed areas of treatment.

Comment 99

APHIS received the following comment, “APHIS’s description of the environmental effects of 

the pesticides at issue failed to properly capture many of their environmental effects”.

APHIS prepared and published separate Final Human Health and Ecological Risk Assessments 

for all the pesticides used by the Grasshopper Programs (November 2019). These documents and 

the associated final EIS are incorporated by reference.

Comment 100

APHIS received the following comment, “Long-term exposure to carbaryl is associated with 

decreased egg production and fertility in birds”.
APHIS would make a single application per year to a treatment area, and could apply 

insecticide at an APHIS rate conventionally used for grasshopper suppression treatments, or 

more typically as reduced agent area treatments (RAATs). Carbaryl has a reported half-life on 

vegetation of three to ten days, therefore, long-term exposure to birds is not anticipated.

The study cited by the commenter noted. Carbaryl is practically nontoxic to birds on both an 

acute oral exposure (LD50 >2,000 mg/kg) and subacute dietary exposure basis (LC50 >5,000 

mg/kg of diet). In addition, no chronic effects were observed at a dietary exposure of 300 mg/kg 

of diet.

Comment 101

APHIS received the following comment, “Carbaryl is considered moderately toxic to mammals 

with decreased pup survival being the most sensitive effect”.

APHIS would make a single application per year to a treatment area, and could apply 

insecticide at an APHIS rate conventionally used for grasshopper suppression treatments, or 

more typically as reduced agent area treatments (RAATs). Carbaryl has a reported half-life on 

vegetation of three to ten days, therefore the chronic exposure to mammals that resulted in 

decreased pup survival is not anticipated.

Comment 102

APHIS received the following comment, “EPA has designated carbaryl as “highly toxic” to bees 

on a short-term exposure basis and ranged from moderately to highly toxic to other insects, mites 

and spiders”.

Although the Grasshopper Program has used the liquid formulation of carbaryl in the past, 

nearly all carbaryl applications this year and for the foreseeable future are likely to be a bait. 

The potential exposures of bees and other pollinators to carbaryl bait are minimal. The risks of 

carbaryl to bees and other non-target organisms are summarized in the human health and 

ecological risk assessment that was prepared to support the final EIS. This analysis is 

incorporated by reference into the final EA.

Comment 103

APHIS received the following comment, “Carbaryl is considered “highly toxic” to certain 

species of fish when exposed to short-term bursts and can reduce the number of eggs spawned 

when fish are exposed to lower levels over a longer period of time”.

The EA provided links to APHIS’ Grasshopper Program webpage where the 2019 EIS and Final 

Human Health and Ecological Risk Assessment for Carbaryl Rangeland Grasshopper and 

Mormon Cricket Suppression Applications are published. Comparison of the distribution of 

acute, sublethal and chronic effects data for fish to the residues estimated using ground and 

aerial ultra-low volume spray and bait applications show that the range of residues do not 

overlap with acute toxicity values, suggesting there is no acute risk to fish species. APHIS 

determined there is some overlap with chronic and sublethal effect values and estimated 

residues. However, carbaryl half-lives in water are typically short and with the proposed one 
time application chronic exposure and risk to fish is not anticipated. Effects from consumption of 

contaminated prey are also not expected to be a significant pathway of exposure, based on the 

low residues and low bioconcentration factor values reported for carbaryl.

APHIS guidelines to buffer bodies of water, streams and rivers were addressed in appendix 1 of 

Draft EA’s AZ-20-01 and AZ-20-02. The FWS Section 7 consultations and FWS letters of 

concurrence. All reduce the exposure to fish species.

Comment 104

APHIS received the following comments, “Carbaryl has been designated “very highly toxic” to 

aquatic invertebrates on an acute exposure basis by the EPA and mesocosm studies that analyze 

how the pesticide affects aquatic community structure have found significant negative effects at 

low levels”.

The EA provided links to APHIS’ Grasshopper Program webpage where the 2019 EIS and Final 

Human Health and Ecological Risk Assessment for Carbaryl Rangeland Grasshopper and 

Mormon Cricket Suppression Applications are published. The risk assessment summarizes the 

available laboratory and field effects data for aquatic invertebrates and carbaryl. The risk 

assessment also summarized the potential exposure and risk to aquatic invertebrates. The EIS 

and carbaryl risk assessment are incorporated by reference into the EAs.

Comment 105

APHIS received the following comment, “The EPA identified potential interactions between 

carbaryl and the androgen pathway in fish, indicating that carbaryl is an endocrine disruptor in 

male aquatic vertebrates”.

Carbaryl half-lives in water are typically short and with the proposed one time application 

chronic exposure and endocrine disruption risk to fish is not anticipated. Effects from 

consumption of contaminated prey are also not expected to be a significant pathway of exposure, 

based on the low residues and low bioconcentration factor values reported for carbaryl. Chronic 

risk is also a conservative estimate because chronic toxicity data is based on long-term 

exposures that what would not be expected to occur from a single application, based on the 

environmental fate of carbaryl in aquatic environments. The final EIS and human health and 

ecological risk assessment for carbaryl provides additional information regarding the 

effects of carbaryl to fish. APHIS guidelines to buffer bodies of water, streams and rivers were 

addressed in appendix 1 of Draft EA’s AZ-20-01 and AZ-20-02. The FWS Section 7 

consultations and FWS letters of concurrence. All reduce the exposure to fish species.

Comment 106

APHIS received the following comment, “On March 12, 2020, the EPA released a draft 

biological opinion finding that carbaryl is likely to adversely affect 1542 out of 1745, or 86% 

percent of all listed species in the U.S. and 713 out of 776 designated critical species’ habitats 

across the U.S.”.

The Endangered Species Act section 7 pesticide consultation process between the U.S. Fish and 

Wildlife Service and the National Marine Fisheries Service (the Services, collectively) and the 
EPA specifically concerns FIFRA pesticide registration and reregistration in the United States, 

including all registered uses of a pesticide. The state-level Biological Assessments for APHIS 

invasive species programs are separate from any consultations conducted in association with 

pesticide registration and reregistration process.

The Agricultural Improvement Act of 2018 (Farm Bill) created a partnership between USDA, 

EPA, the Services, and the Council on Environmental Quality to improve the consultation 

process for pesticide registration and reregistration. USDA is committed to working to ensure 

consultations are conducted in a timely, transparent manner and based on the best available 

science. The Revised Method for National Level Listed Species Biological Evaluations of 

Conventional Pesticides provides a directionally improved path to ensuring that pesticides can 

continue to be used safely for agricultural production with minimal impacts to threatened and 

endangered species.

APHIS provided information about use of carbaryl to EPA for the FIFRA consultation for 

carbaryl. The Grasshopper Program use of carbaryl has in the past comprised substantially less 

than 1% of the percent crop treated (PCT) for rangeland use of carbaryl. This is the case for the 

reasonably foreseeable future. For rangeland, in the EPA BE, the Grasshopper Program’s very 

low usage was rounded up to <1% PCT, which gives an overestimate of rangeland acres treated 

and thus endangered species risk. APHIS use of carbaryl is even smaller compared to all uses of 

carbaryl nationwide. Further, the Grasshopper Program consults directly with the Services to 

ensure program activities do not adversely affect protected species or their critical habitat.

Comment 107

APHIS received the following comment, “EPA found many Arizona species were likely to be 

adversely affected. This is a chemical far too toxic for APHIS to consider using across wide 

swaths of land in Arizona.”

Carbaryl is presently approved by the EPA and registered in Arizona. The APHIS proposed use 

for carbaryl in Arizona is not proposed for use across wide swaths of Arizona but in small 

grazing allotments that require a suppression treatment, most likely as a bait treatment. It should 

be noted that the current labeled uses for carbaryl grasshopper treatments are at much higher 

labels and can be applied with more frequency than what APHIS is proposing for use in Arizona. 

In addition carbaryl use by the Program is minor compared to the preferred alternative 

diflubenzuron. APHIS has evaluated the risk of carbaryl use in the Program and in general the 

conclusions are consistent with other risk assessments demonstrating low risk when adhering to 

label requirements. Additional mitigation measures used by APHIS further reduces the risk to 

human health and the environment.

As stated in the final EIS, APHIS has completed programmatic consultation with the National 

Marine Fisheries Service (NMFS). APHIS has reinitiated programmatic consultation with 

NMFS to include chlorantraniliprole. In the interim, APHIS will consult with NMFS at the State 

level if there is a proposal to apply chlorantraniliprole. The NMFS consultation does not apply 

to species in Arizona since there are no federally listed species under NMFS jurisdiction 

however the information was provided in response to comments regarding the final EIS. APHIS 

submitted a programmatic biological assessment to the FWS in 2015. APHIS is currently 
working with the FWS to update and complete the biological assessment and receive 

concurrence. The intent of the programmatic biological assessment is to provide consistent 

mitigation measures for listed species that may co-occur with Program treatments. Consultation 

with the FWS is still being completed at the local level prior to any treatments. No APHIS 

treatments are made in States without prior concurrence from the FWS or NMFS regarding 

federally-listed species. This information is also summarized in the final EIS.

Local FWS Section 7 consultations were entered into prior to the DRAFT EA# AZ-20-01 and AZ20-02. The letters of concurrence from FWS regarding the local site specific biological

assessment was included as appendix 7 of Draft EA# AZ-20-02. This letter is dated February 10, 

2020. Consultations regarding Tribal Lands in Arizona, come from the Region 2 office. The 

letter of concurrence is signed by the FWS Region 2 office in Albuquerque, NM. At the time of 

the Draft EA#AZ-20-01 the Letter of Concurrence was written and the lead biologist stated 

verbally that the letter was sent for signature. This letter of concurrence from FWS was dated 

April 1, 2020. The Final EA# AZ-20-01 and AZ-20-02 will again have the letters of concurrence 

cited in the appendix 7 of both EA’s.

APHIS consulted with the FWS on federally-listed species that may occur within the county or 

areas where grasshopper and Mormon cricket treatments may be required. APHIS works 

closely with the FWS to determine the application of protection measures and where those 

measures should be applied prior to any treatments. APHIS also evaluated the potential direct 

and indirect impacts to non-target species which is summarized in the final human health and 

ecological risk assessments for each insecticide. 

Comment 108

APHIS received the following comment, “The European Union banned carbaryl in 2007 due to, 

among other things, “...a high long-term risk for insectivorous birds and a high acute risk to 

herbivorous mammals, a high acute and long-term risk to aquatic organisms and a high risk for 

beneficial arthropods”.

APHIS summarizes the risk of carbaryl to non-target organisms in final human health and 

ecological risk assessment that was part of the recently published final EIS. Available effects 

data and the exposures that would be expected from proposed use in the grasshopper and 

Mormon cricket program are reduced based on mitigation measures (ex. RAATS, aquatic 

buffers) application methods and formulation types which further reduce risk.

Comment 109

APHIS received the following comments, “Carbaryl is classified as “likely to be carcinogenic to 

humans” based on treatment-related hemangiosarcoma development in mice”.

The levels of carbaryl that caused the above-mentioned effects to mice are above exposure 

concentrations that would be expected to occur for the public as well as workers and applicators 

in the APHIS grasshopper and Mormon cricket suppression program. The risk to human health 

from carbaryl use, including the proposed APHIS use, have been evaluated by APHIS and are 

discussed in the final human health and ecological risk assessment for carbaryl. It should be 
noted that other agencies have evaluated the risk to carbaryl at much higher application rates 

than those used in the grasshopper and Mormon cricket program.

Comment 110

APHIS received the following comments, “EPA has determined that humans can be exposed to 

more than 4 times the amount of carbaryl known to cause neurotoxicity from some legal uses of 

the pesticide. EPA also found that the current labelled uses of carbaryl may result in neurotoxic 

harms to mixers, loaders and applicators.”

The EA provided links to APHIS’ Grasshopper Program webpage where the 2019 EIS and Final 

Human Health and Ecological Risk Assessment for Carbaryl Rangeland Grasshopper and 

Mormon Cricket Suppression Applications are published. APHIS evaluated the potential human 

health risks from the proposed use of carbaryl ULV sprays and carbaryl bait applications and 

determined that the risks to human health are low. The lack of risk to human health is based on 

the low probability of human exposure and the favorable environmental fate and effects data.

APHIS treatments are conducted in rural rangeland areas where agriculture is a primary 

economic factor. Rural rangeland areas consist of widely scattered, single dwellings in ranching 

communities with low population density. Risk to the general public from carbaryl ground or 

aerial applications is also expected to be minimal due to the low-population areas proposed for 

treatment, adherence to label requirements, and additional Program measures designed to 

reduce exposure to the public. APHIS is not obligated to analyze the risk posed by all legal uses 

of carbaryl, but rather the Grasshopper Program formulations and application rates.

The proposed use of carbaryl as a ULV spray, or a bait, and adherence to label requirements 

substantially reduces the potential for exposure to humans. APHIS does not expect adverse 

health risks to workers because of the low potential for exposure to carbaryl when applied 

according to label directions and use of personal protective equipment. APHIS quantified the 

potential risks associated with accidental exposure of carbaryl for workers during mixing, 

loading, and application. The quantitative risk evaluation results indicate no concerns for 

adverse health risk for Program workers from carbaryl applications in accordance with 

program standard operating procedures for safety.

Comment 111

APHIS received the following comment, “EPA has found that all use scenarios 

of chlorantraniliprole can result in direct or indirect effects to all listed species”.

The EPA risk assessment is a screening level ecological risk assessment that evaluated risk 

under a variety of application rates with most being well above use rates proposed in the APHIS 

Grasshopper Program. APHIS prepared a final human health and ecological risk assessment 

that assesses the risk of APHIS Program treatments. The state-level Biological Assessments for 

APHIS invasive species programs are separate from any consultations conducted in association 

with pesticide registration and reregistration process.
As previously stated, the Grasshopper Program will not be using chlorantraniliprole in Arizona 

during 2020. Therefore any chlorantraniliprole exposure scenarios which the commenter is 

concerned about are not relevant at this time.

Comment 112

APHIS received the following comment, “EPA has found that all use scenarios 

of chlorantraniliprole can result in direct or indirect effects to all listed species. 

Chlorantraniliprole is considered “very highly toxic” to freshwater invertebrates and EPA found 

that many uses of it can result in acute and chronic harms to aquatic invertebrates. This was the 

case for both aerial and ground spray applications. Sublethal doses can impair locomotion in 

bees more than seven days post exposure. A 2013 European Food Safety Authority analysis 

of chlorantraniliprople found that the use of the pesticide poses a high risk to soil macroorganisms, aquatic invertebrates and sediment dwelling organisms.” and “APHIS must 

consider chlorantraniliprole substantial environmental impacts, including population level 

effects”.

The EA provided links to APHIS’ Grasshopper Program webpage where the 2019 EIS and Final 

Human Health and Ecological Risk Assessment for Chlorantraniliprole Rangeland Grasshopper 

and Mormon Cricket Suppression Applications is published. The document summarizes 

available effects data and characterizes risk to human health and non-target organisms based on 

the use pattern proposed by the Program. Results from the risk assessment suggest low risk 

of chlorantraniliprole to non-target aquatic organisms and most terrestrial invertebrates.

As previously stated, the Grasshopper Program will not be using chlorantraniliprole in Arizona 

during 2020. Therefore any chlorantraniliprole exposure scenarios which the commenter is 

concerned about are not relevant at this time.

Comment 113

APHIS received the following comments, “Diflubenzuron is considered “highly” to “very highly 

toxic” to aquatic invertebrates. In a 2018 analysis, EPA found that the registered, labeled uses of 

diflubenzuron may result in freshwater invertebrate exposure at up to 550 times the level known 

to cause harm. Diflubenzuron exposure to honeybees and other pollinators at the larval stage was 

estimated to be more than 500 times the level known to cause harm. Although arthropods are not 

a part of EPA’s ecological risk assessment, the European Food Safety Authority found that 

“Juvenile non-target arthropods were very sensitive to diflubenzuron. Very large in-field nospray buffer zones would be needed to protect nontarget arthropods. There is no reason for 

APHIS to exclude consideration of impacts to arthropods in its analysis of this pesticide.” 

and “APHIS also acknowledges the pollinator impacts but attempts to diminish them without 

providing evidence on how or why they are not significant”.

The EA provided links to APHIS’ Grasshopper Program webpage where the 2019 EIS and Final 

Human Health and Ecological Risk Assessment for Diflubenzuron Rangeland Grasshopper and 

Mormon Cricket Suppression Applications are published. The EPA risk assessment evaluated 

risk to aquatic organisms and pollinators based on application rates, methods of application and 

use patterns that would result in greater exposure and risk to aquatic and terrestrial 

invertebrates. APHIS evaluated risks to these groups of non-target organisms based on methods 
of application consistent with Program applications and other mitigation measures for 

diflubenzuron. The exposure potential is reduced compared to label uses due to many factors.

This includes but is not limited to reduced application rates, one application per season, use of 

RAATs and buffers from aquatic habitats. APHIS relied on laboratory and field collected data 

regarding diflubenzuron effects to aquatic and terrestrial invertebrates to show that risk is low 

for most non-target invertebrates. 

Characterization of risk to aquatic species from Program-specific diflubenzuron applications 

was made by comparing the residue values in the exposure analysis from ground and aerial 

applications to the distribution of available acute and chronic fish toxicity data. Residue values 

were below the distribution of acute and chronic response data, suggesting that direct risk to 

aquatic species is not expected from diflubenzuron applications. More specifically, the 

distribution of aquatic invertebrate toxicity data is above the residues estimated from spray drift 

models for Grasshopper Program ground and aerial applications of diflubenzuron.

The Endangered Species Act section 7 pesticide consultation process between the U.S. Fish and 

Wildlife Service and the National Marine Fisheries Service (the Services, collectively) and the 

EPA specifically concerns FIFRA pesticide registration and reregistration in the United States, 

including all registered uses of a pesticide. The Grasshopper Program treatments employ 

methods and diflubenzuron application rates that result in substantially lower freshwater 

invertebrate exposures than the rate cited by the EPA and the commenter.

The EPA Preliminary Risk Assessment to Support Re-registration Review examines all legal uses 

of diflubenzuron, of which the Grasshopper Program constitutes a small fraction. APHIS is not 

obligated to examine all legal uses of the pesticide, but rather those contemplated by the 

program. The EA provided links to APHIS’ Grasshopper Program webpage where the 2019 EIS 

and Final Human Health and Ecological Risk Assessment for Diflubenzuron Rangeland 

Grasshopper and Mormon Cricket Suppression Applications are published. Characterization of 

risk to aquatic species from diflubenzuron applications was made by comparing the residue 

values in the exposure analysis from ground and aerial applications to the distribution of 

available acute and chronic fish toxicity data. Residue values were below the distribution of 

acute and chronic response data, suggesting that direct risk to aquatic species is not expected 

from diflubenzuron applications. More specifically, the distribution of aquatic invertebrate 

toxicity data is above the residues estimated from spray drift models for Grasshopper Program 

ground and aerial applications of diflubenzuron.

The EA provided links to APHIS’ Grasshopper Program webpage where the 2019 EIS and Final 

Human Health and Ecological Risk Assessment for Diflubenzuron Rangeland Grasshopper and 

Mormon Cricket Suppression Applications are published. The APHIS analysis noted 

Diflubenzuron has low toxicity and risk to some nontarget terrestrial invertebrates, including 

pollinators such as honey bees.

Comment 114

APHIS received the following comment, “APHIS also acknowledges the pollinator impacts but 

attempts to diminish them without providing evidence on how or why they are not significant. 

It does not mention that Arizona is home to an amazing abundance of native bees and 

pollinators, and improperly uses honeybees as a surrogate for pollinators, when native pollinators 
are far more sensitive due to the lack of hive buffering effects. This is not a pesticide that should 

be applied to broad swaths of land. It is highly toxic to far too many species of importance in 

Arizona.”

Grasshopper IPM field studies have shown diflubenzuron to have a minimal impact on ants, 

spiders, predatory beetles, and scavenger beetles. There was no significant reduction in 

populations of these species from 7 to 76 days after treatment. Although ant populations 

exhibited declines of up to 50%, these reductions were temporary, and population recovery was 

described as immediate (Catangui et al., 1996). No significant reductions in flying non-target 

arthropods, including honey bees, were reported. Within one year of diflubenzuron applications 

in a rangeland environment, no significant reductions of bee predators, parasites, or pollinators 

were observed for any level of diflubenzuron treatment (Catangui et al., 1996).

Comment 115

APHIS received the following comment, “Diflubenzuron is present in the excreted manure and 

urine of cattle where they range and the cumulative exposure must be considered in accordance 

with the ESA and NEPA’s mandate that an action agency take into account the environmental 

baseline”.

APHIS recognizes that some diflubenzuron resides may be present in urine and feces from cattle 

that feed on forage immediately after diflubenzuron treatment; however this pathway of 

exposure is expected to be minor based on the proposed use pattern of diflubenzuron in the 

Program. Low application rates applied only once per season will reduce the amount of 

diflubenzuron present in manure and urine. In addition some metabolism of 

diflubenzuron occurs in animals, and there will be further environmental degradation once 

excreted. 

Comment 116

APHIS received the following comment, “Malathion is considered “very highly toxic” to all 

aquatic and terrestrial invertebrates, as well as aquatic vertebrates such as fish. In addition 

indirect effects to taxa should be considered.”

The EA provided links to APHIS’ Grasshopper Program webpage where the 2019 EIS and Final 

Human Health and Ecological Risk Assessment for Malathion Rangeland Grasshopper and 

Mormon Cricket Suppression Applications are published. The risk assessment summarizes 

available laboratory and field collected aquatic and terrestrial effects data for malathion and 

then estimated risk based on conservative estimates of exposure. APHIS recognizes in the risk 

assessment that malathion can be toxic to sensitive non-target species however the effects have 

to be considered in relation to the potential for exposure to estimate risk, as well as historical 

use in the Program which is negligible. 

As previously stated, the Grasshopper Program will not be using malathion during 2020 in 

Arizona.
Comment 117

APHIS received the following comment, “When exposed to malathion for longer periods of 

time, female birds displayed regressed ovaries, reduced number of hatched eggs and enlarged 

gizzards”.

The EA provided links to APHIS’ Grasshopper Program webpage where the 2019 EIS and Final 

Human Health and Ecological Risk Assessment for Malathion Rangeland Grasshopper and 

Mormon Cricket Suppression Applications are published.

Several reproductive and developmental studies have been conducted with birds. The lowest 

median lethal dose to chicken embryos (eggs) was 3.99 mg per egg for 4-day embryos 

(Greenberg and LaHam, 1969). The median lethal concentration for field applications of 

malathion to mallard duck eggs was found to be 4.7 lbs. a.i./acre (Hoffman and Eastin, 1981). 

This is approximately five times greater than the maximum rate for rangeland grasshopper 

(0.928 lbs. a.i./acre), 7.6 times greater than the maximum APHIS application rate 

(0.619 lbs. a.i./acre), and nearly 19 times greater than the average RAATs rate applied by 

APHIS.

No effect on reproductive capacity of chickens was found at dietary concentrations as high as 

500 ppm in feed (Lillie, 1973). Based on the results from chronic reproduction studies using the 

bobwhite quail and mallard duck, the NOEC values were 110 and 1,200 ppm, respectively. The 

most sensitive endpoint in the quail study was regressed ovaries and reduced egg hatch at the 

next highest test concentration (350 ppm). The effect endpoint in the mallard study was growth 

and egg viability at the 2,400 ppm level Lowest Observed Effect Concentration (LOEC).

APHIS expects that direct avian chronic effects would be minimal for most species. The 

preferred use of RAATs during application reduces these risks by reducing residues on treated 

food items and reducing the probability that they will only feed on contaminated food items. In 

addition, malathion degrades quickly in the environment and residues on food items are not 

expected to persist.

As previously stated, the Grasshopper Program will not be using malathion in Arizona during 

2020.

Comment 118

APHIS received the following comments, “Malathion degrades into malaoxon, which has been 

shown to be at least 22 times more toxic than the parent molecule”.

Similar to other organophosphate pesticides, malathion inhibits the enzyme AChE in the central 

and/or peripheral nervous system. Malathion is metabolized to malaoxon, which is the 

active AChE inhibiting metabolite. AChE inhibition is through phosphorylation of the serine 

residue at the active site of the enzyme, and leads to accumulation of acetylcholine and 

ultimately neurotoxicity. Malaoxon goes through detoxification with subsequent metabolism. 

Absorption and distribution of malathion and malaoxon are rapid with extensive metabolism and 

no accumulation in tissues.
Carboxylesterase detoxifies malathion and malaoxon to polar and water-soluble compounds for 

excretion. A rat metabolism study showed 80 to 90% of malathion excretion in the urine in the 

first 24 hours of exposure. Mammals are less sensitive to the effects of malathion than insects 

due to greater carboxylesterase activity resulting in less accumulation of malaoxon.

Available aquatic toxicity data show that malaoxon is approximately 1.5 to 6 times more toxic to 

fish and 1.8 to 93 times more toxic to amphibians. FMC, in their 2019 public response to 

the Grasshopper Program EIS, reported that malaoxon is 0.80 to 2.58 times more toxic to fish 

than malathion based on data that were determined to meet their criteria for 

acceptability (FMC, 2014). The conversion of malathion to malaoxon in aquatic environments 

can range from approximately 1.8 to 10% (CDPR, 1993; Bavcon et al., 2005; USEPA, 2012).

While APHIS assumed that malaoxon is most likely more toxic to aquatic invertebrates than the 

parent; however, due to its low percentage of occurrence in aquatic systems and its rapid 

breakdown, malaoxon is not anticipated to pose a greater aquatic risk when compared to 

malathion.

As previously stated, the Grasshopper Program will not be using malathion in Arizona during 

2020.

Comment 119

APHIS received the following comment, “A 2017 EPA biological evaluation also found that the 

use of malathion is likely to adversely affect 1778 out of 1835 listed species in the U.S. and 784 

out of 794 critical species’ habitats across the U.S. These findings were based on methodology 

recommended by the National Academy of Sciences. EPA found many Arizona species were 

likely to be adversely affected, such as the yellow billed cuckoo. The U.S. Fish and Wildlife 

Service later drafted a biological opinion finding that malathion is likely to jeopardize the 

continued existence of 1284 threatened and endangered species. This is an astounding number of 

jeopardy calls for a single pesticide, and makes it even more astounding that APHIS would 

continue to consider using it for grasshopper and cricket control.”

The Endangered Species Act section 7 pesticide consultation process between EPA and the 

Services specifically concerns FIFRA pesticide registration and reregistration in the United 

States, including all registered uses of the pesticide. The Grasshopper Program use of malathion 

comprised nearly none of the percent crop treated for rangeland in the past, and this remains 

APHIS’ expectation for the foreseeable future. Further, the Grasshopper Program consults 

directly with the Services to ensure program activities do not adversely affect protected species 

or their critical habitat.

As previously stated, the Grasshopper Program will not be using malathion in Arizona during 

2020.

Comment 120

APHIS received the following comment, “California’s Proposition 65 list of chemicals known to 

cause cancer and has been designated as having suggestive evidence of carcinogenicity by the 
EPA for instances of liver, oral palate mucosa and nasal respiratory epithelium tumor formation 

in mice.”

The EA provided links to APHIS’ Grasshopper Program webpage where the 2019 EIS and Final 

Human Health and Ecological Risk Assessment for Malathion Rangeland Grasshopper and 

Mormon Cricket Suppression Applications are published. As previously stated, the Grasshopper 

Program will not be using malathion in Arizona during 2020.

Comment 121

APHIS received a comment that, “EPA has determined that humans can be exposed to more than 

6 times the amount of malathion known to cause neurotoxicity from some legal uses of the 

pesticide. EPA also found that the current labelled uses of malathion may result in neurotoxic 

harms to those exposed to pesticide drift from aerial applications at labelled rates”. The 

commenter also pointed out that occupational applicators, mixers and loaders can be exposed to 

malathion through inhalation and dermal absorption at levels above what the EPA considers safe 

– even when using required personal protective equipment.”

APHIS evaluated the risk to human health, including neurotoxicity data in its finale human 

health and ecological risk assessment. The risk assessment was prepared based on APHIS use 

patterns and Program mitigations that reduce risk to human health. APHIS is not obligated to 

ensure the EA and supporting documents analyze the risk posed by all legal uses of malathion, 

but rather the Grasshopper Program methods and application rates.

Malathion exposure to the general public is not expected from the program use based on label 

requirements and program standard operating procedures that prevent potential exposure. Only 

protected handlers may be in the area during application, and entry of the general public into 

the treated area is not allowed during the re-entry interval period. APHIS treatments are 

conducted on rural rangelands, where agriculture is a primary economic factor and widely 

scattered dwellings in low population density ranching communities are found. The program 

requires pilots avoiding flights over congested areas, water bodies, and other sensitive areas. 

Aerial applications are not allowed while school buses are operating in the treatment area; 

within 500 feet of schools or recreational facilities; when wind velocity exceeds 10 miles per 

hour (mph) (unless a lower wind speed is required under State law); when air turbulence could 

seriously affect the normal spray pattern; and/or temperature inversions could lead to off-site 

movement of spray. The Grasshopper Program also notifies residents within treatment areas, or 

their designated representatives, prior to application to reduce the potential for incidental 

exposure.

APHIS acknowledges workers in the program are the most likely human population segment to 

be exposed to malathion during grasshopper treatments. Occupational exposure to malathion 

may occur through inhalation and dermal contact during ground and aerial applications. Direct 

contact exposure from the application of a malathion ULV spray will be minimal with adherence 

to label requirements, the use of personal protective equipment (PPE), general safety hygiene 

practices, and restricted entry intervals into treated areas after application. EPA estimates of 

risk to workers is based on use patterns and rates that result in greater exposure to malathion 

than would occur in the APHIS program. APHIS evaluated the risk from program specific uses 
of malathion and demonstrated low risk to applicators. It should also be noted that historical 

malathion use in the Program is negligible further reducing the potential for any types of human 

health risk.

As previously stated, the Grasshopper Program will not be using malathion in Arizona during 

2020. Therefore any malathion exposure scenarios which the commenter is concerned about are 

not relevant at this time.

Comment 122

APHIS received the following comment, “APHIS touts EPA-approval as an indication that the 

pesticides that the agency proposes to use are safe. However, under our nation’s pesticide laws, 

EPA-approval is an indication that use of the pesticide won the agency’s cost-benefit analysis, 

and should not be misconstrued as a finding of safety.”

The EA provided links to APHIS’ Grasshopper Program webpage where the 2019 EIS 

and human health and ecological risk assessments for pesticides used by the 

Grasshopper Program are published. APHIS does not assert the FIFRA registration of the 

pesticides by the EPA demonstrates that the Grasshopper Program uses are safe. Instead the 

extensive risk analysis published by APHIS considered whether the suppression of grasshopper 

population will have significant environmental impacts, in accordance with NEPA.

Comment 123

APHIS received the following comment, “APHIS does not discuss or account for how pesticides 

impact overall soil health or the health of any organisms that reside in soil.”

The EA provided links to APHIS’ Grasshopper Program webpage where the 2019 EIS and 

HHERA for pesticides used by the Grasshopper Program are published. The HHERA contain 

extensive analysis of pesticide effects on terrestrial vertebrates, many of which reside in soil.

Comment 124

APHIS received the following comment, “Impacts on soil health can impact listed and non-listed 

plants by impacting nutrient cycling, soil oxygenation and soil water retention, as well as listed 

and non-listed animals that rely on plants or soil organisms for their survival.”

The Grasshopper Program applies pesticides in accordance with current label restrictions 

and program operational procedures that are mitigations to minimize significant exposure of 

soil, water, and air to insecticides; grasshopper chemical treatments are not expected to persist 

or bioaccumulate in the environment. APHIS evaluated these effects in human health and 

ecological risk assessments that were prepared along with the final EIS for the grasshopper and 

Mormon cricket suppression program.

Comment 125

APHIS received the following comment, “Carbaryl was ranked as extremely toxic to earthworms 

in a lab test rating pesticide toxicity from relatively nontoxic, moderately toxic, very toxic, 

extremely toxic, and super toxic.”
The study was a comparison of the toxicology of 45 pesticide to determine the LC50. These 

studies exposed earthworms to varying concentrations of carbaryl to determine toxicological 

endpoints. Based on the extremely high doses, the impact to the survival of earthworms was not 

only unsurprising, but the object of the studies. APHIS would like to note this laboratory dosing 

procedure is not comparable to any exposure levels resulting from the use of carbaryl ultra-low 

volume sprays by the Grasshopper Program.

Comment 126

APHIS received the following comment, “A single application of carbaryl in a field study caused 

a 38% reduction in survival of total Lumbricidae, and a 78% reduction in total earthworms for at 

least 5 weeks.”

APHIS would like to note the “single application” involved applying carbaryl 6 times on a 

weekly interval to its assigned plots at the highest recommended dose (i.e. Sevin at 9.12 mg/m2), 

a rate that is greater than 16 times the Grasshopper ultra-low volume liquid rate (0.56 mg/m2). 

The Grasshopper program only makes one application per year, rather than six weekly 

treatments. Also, the field study found carbaryl significantly inhibited earthworm feeding activity 

for at least three weeks without leading to any earthworm death.

In addition, the 78% reduction in earthworm casts noted in the comment resulted from an 

application of a combination of clothianidin and bifenthrin pesticides.

Comment 127

APHIS received the following comment, “Carbaryl significantly impacted the survival or 

population abundance of E. fetida, E. andrei, Lumbricus terrestris, 

and Lumbricus rubellus, Aporrectodea caliginosa, and Allolobophora chlorotica.”

These studies exposed earthworms to varying concentrations of carbaryl to determine 

toxicological endpoints (NOEC, LC50). Based on the extremely high doses, the impact to the 

survival of earthworms was not only unsurprising, but the object of the studies. For example in 

Lima et al. 2011, ten adult worms with individual fresh weight between 300 and 600 mg, were 

exposed to different carbaryl concentrations (20, 40, 60, 80, 100 mg/kg). APHIS would like to 

clarify the Grasshopper Program applies carbaryl ultra-low volume spray at a rate of half a 

pound active ingredient per acre.

Comparison of the results of paper contact test with those obtained in soils clearly demonstrates 

that the contact test has no predictive values for the toxicity of an insecticide in soils, though it is 

important for the initial screening of the environmental chemicals. The differences between 

lowest and highest LC50 values of insecticides for M. posthuma and E. fetida in paper contact 

method were only 6.9 and 2.5-fold respectively while in soil they were over 38 and 26-fold. 

These data demonstrated that worms could tolerate higher concentrations in soil than on moist 

filter paper. This difference in the behavior of the insecticide may probably due to the rate of 

diffusion/uptake of insecticide from the medium into the body of the earthworm. It is well 

reported in the literature that insecticides are adsorbed on soil medium through strong binding 

by organic matter contents in soils (Davis, 1971, Van Gestel and Van Dis, 1988). Hence, the 

availability of insecticide for diffusion will be less from the soil than the impregnated filter 
paper. Contact filter paper test can be used as an initial screening technique to assess the 

relative toxicity of chemicals; however it fails to represent the situation in the soil ecosystem. 

Artificial soil test is more representative of the natural environment of earthworms and acute 

toxicity data on several insecticides can be used in the ecological risk assessment on soil 

ecosystems.

Comment 128

APHIS received the following comment, “In another study, carbaryl induced an avoidance 

response in E. fetida. Soil structure changes were observed between the control and carbaryl 

treated sites, with higher treatments of carbaryl causing significantly more lumps in the soil due 

to earthworm inactivity.”

The commenter cited a study where worms were rinsed in tap water and transferred to the flasks 

containing 2 ml solution per worm. The flasks were gently tilted every 5 min and the exposure 

was terminated after 30 min. The worms were removed, rinsed in cold tap water and transferred 

to Petri dishes (five worms in each) containing soil but no pesticide. The worms were inspected 

at intervals during 80 days or until all the worms were dead or had recovered. The structure of 

the soil in the Petri dishes was observed in order to get an idea about the ability to work the soil 

after pesticide treatment. APHIS would like to note this laboratory dosing procedure is not 

comparable to any exposure scenario resulting from the use of carbaryl ultra-low volume sprays 

by the Grasshopper Program.

Notably, E. foetida could tolerate high concentrations of carbaryl without dying, although low 

concentrations severely affected its ability to work the soil or to disappear from the soil surface. 

The researchers believe the solutions were equivalent to 64, 32, 16, 8 and 4 mg/kg of pesticide, 

and found that carbaryl did not kill E. foetida in concentrations up to 64 mg/kg, from the 800 

mg/l solution.

The avoidance test is a behavioral test with several advantages (simple, quick and cheap) but 

one drawback: this is not a measure of toxicity but rather a measure of repellence 

(Capowiez and Bérard, 2006), and thus is termed ‘measure of habitat modification’. As there is 

not always a direct relationship between avoidance and toxicity, an improvement of this test was 

recently proposed by Sanchez-Hernandez (2006).

APHIS would like to clarify the Grasshopper Program applies carbaryl ultra-low volume spray 

at a rate of half a pound active ingredient per acre. If a cubic foot of rangeland soil weighs 75 

pounds, 1 acre (43,560 ft.2) of soil two inches deep would weigh 544,500 pounds, or 246,981 

kilograms. The maximum rate used by the Grasshopper Program to apply carbaryl as an ultralow volume spray is half a pound (226796 mg) active ingredient per acre. Therefore, the 

maximum concentration of 0.92 mg carbaryl spray per kg of soil could result from program 

applications. However, this analysis assumes none of the foliar spray settled on vegetation, 

and all of the carbaryl is instantaneously absorbed into the top two inches of soil. In addition, 

this maximum concentration was less than the lowest concentration which the researchers 

determined has significant effects on the reduction of the P. excavatus hatching rate (1.51 mg 

carbaryl per kg of soil). 
Comment 129

APHIS received the following comment, “Carbaryl negatively affected the biomass 

of E. andrei, Perionyx excavates, total earthworms, and Lumbricus terrestris at a tenth of the 

recommended dose.”

The carbaryl concentrations used for each test species was chosen based on the LC50/EC50 

previously carried out and reported by Lima et al. (2011). This was also a toxicological endpoint 

study where the acute toxicity was determined by exposing the worms to a nominal concentration 

range of 20 to 100 mg/kg of technical grade carbaryl. The application rate was 850 grams per 

hectare of Sevin L85 which is equal to 1.12 pounds active ingredient carbaryl per acre, 

compared with Sevin XLR which is 44.1 % applied at half a pound active ingredient per acre by 

the Grasshopper Program.

This study was primarily designed to validate the production of casts by earthworms as a 

biomarker for behavioral effects. While the significant effects in earthworm weight observed at 

low concentrations of carbaryl are concerning, Grasshopper program applications of foliar 

sprays are unlikely to result in the subsurface soil becoming saturated at the concentrations 

created in the laboratory.

Comment 130

APHIS received the following comment, “A 60-99% reduction in earthworm biomass and 

density due to carbaryl treatment lasted 20 weeks. Burial of organic matter was also negatively 

affected. Casting activity of earthworms was reduced by 90%, and 71% and 81% after 3 and 5 

weeks, respectively.”

The researchers made two applications of carbaryl at a rate of 8 lbs. ai/acre, 16 times greater 

than the maximum spray rate employed by the Grasshopper Program. The Grasshopper 

Program only makes one application per year. In addition, the foliar spray of ultra-low volume 

carbaryl over rangeland is unlikely to result in subsurface soil concentrations comparable to the 

direct turfgrass application made in this study.

Comment 131

APHIS received the following comment, “Carbaryl negatively affected growth in E. fetida, and 

the feeding rate of Diplocardia spp. Total cast production of L. terrestris was significantly 

impacted at one-tenth of the recommended field rate.”

The lowest test concentration that effected E. fetida resulted from saturation of the test media 

with 25 mg/kg of carbaryl. Another field study found a single application of carbaryl 

significantly inhibited earthworm (Diplocardia spp.) feeding activity for at least three 

weeks without leading to any earthworm death. APHIS would like to note the “single 

application” involved applying carbaryl 6 times on a weekly interval to its assigned plots at the 

highest recommended dose (i.e. Sevin at 9.12 mg/m2), a rate that is greater than 16 times the 

Grasshopper ultra-low volume liquid rate (0.5 lbs. a.i./acre). The Grasshopper program only 

makes one application per year, rather than six weekly treatments.
Comment 132

APHIS received the following comment, “Reproduction of E. fetida, 

and Perionyx excavatus was negatively affected, with the hatching rate of P. excavatus reduced 

by 87% at sublethal concentrations lower than the recommended field rate. A total loss of 

burrowing was observed at 4 and 8 mg/kg after 40 minutes and at 1 and 2 mg/kg after 80 

minutes.”

The lowest test concentration that effected E. fetida resulted from saturation of the test media 

with 25 mg/kg of carbaryl. In another study the reduction of the P. excavatus hatching rate was 

observed at a concentration of 1.51 mg carbaryl per kg of soil.

APHIS would like to clarify the Grasshopper Program applies carbaryl ultra-low volume spray 

at a rate of half a pound active ingredient per acre. If a cubic foot of rangeland soil weighs 75 

pounds, 1 acre (43,560 ft.2) of soil two inches deep would weigh 544,500 pounds, or 246,981 

kilograms. The maximum rate used by the Grasshopper Program to apply carbaryl as an ultralow volume spray is half a pound (226796 mg) active ingredient per acre. Therefore, the 

maximum concentration of 0.92 mg carbaryl spray per kg of soil could result from program 

applications (0.92 mg/kg). However, this analysis assumes none of the foliar spray settled on 

vegetation, and the carbaryl instantly absorbed into the top two inches of soil, thus mirroring the 

laboratory conditions. In addition, this maximum concentration was less than the lowest 

concentration which the researchers determined has significant effects on the reduction of the 

P. excavatus hatching rate (1.51 mg/kg).

Comment 133

APHIS received the following comment, “Morphological abnormalities and histological changes 

in E. andrei and M. posthuma were observed at very low, sublethal doses ranging from 0.24-1.20 

mg/kg and 0.5-1.20 mg/kg, respectively.”

The cited study did not test E. andrei but rather E. fetida a closely related species. The sublethal 

doses were derived from anecdotal observations during filter paper tests where concentrations 

were measured in μg/cm2 not mg/kg. APHIS would also like to note the researcher’s skepticism 

about toxicity tests where the worms are dosed on saturate filter paper. They wrote: Comparison 

of the results of paper contact test with those obtained in soils clearly demonstrates that the 

contact test has no predictive values for the toxicity of an insecticide in soils, though it is 

important for the initial screening of the environmental chemicals. The differences between 

lowest and highest LC50 values of insecticides for M. posthuma and E. fetida in paper contact 

method were only 6.9 and 2.5-fold respectively while in soil they were over 38 and 26-fold. 

These data demonstrated that worms could tolerate higher concentrations in soil than on moist 

filter paper. This difference in the behavior of the insecticide may probably due to the rate of 

diffusion/uptake of insecticide from the medium into the body of the earthworm. It is well 

reported in the literature that insecticides are adsorbed on soil medium through strong binding 

by organic matter contents in soils (Davis, 1971, Van Gestel and Van Dis, 1988). Hence, the 

availability of insecticide for diffusion will be less from the soil than the impregnated filter 

paper. Contact filter paper test can be used as an initial screening technique to assess the 

relative toxicity of chemicals; however it fails to represent the situation in the soil ecosystem. 

Artificial soil test is more representative of natural environment of earthworms and acute 
toxicity data on several insecticides can be used in the ecological risk assessment on soil 

ecosystem.

Comment 134

APHIS received the following comment, “Carbaryl impacted multiple biochemical biomarkers in 

E. andrei, including Acetylcholinesterase (AChE), methoxyresorufin-O-deethylase (MROD), and 

NADH and NADPH red cytochrome reductase.”

This study exposed earthworms to carbaryl in artificial soil at concentrations of 12, 25 and 50 

mg/kg. The research showed that carbaryl inhibited biotransformation enzyme activities but did 

not induce oxidative stress. Since carbaryl is a cholinesterases inhibitor, changes detected in 

acetylcholinesterase activities were not surprising. The acetylcholinesterase activity reduction 

was not complete and the residual activity was stable whatever the dose or the exposure duration 

because of the presence in E. andrei of a non-inhibited, non-specific cholinesterases.

APHIS would like to note the lowest tested soil concentration of carbaryl that caused these 

effects (12 mg/kg) is approximately 12 times greater than the hypothetical concentrations that 

could result from Grasshopper Program treatments where none of the foliar ultra-low volume 

spray settles on vegetation, and the chemical is instantly and uniformly mixed into the top two 

inches of soil.

Comment 135

APHIS received the following comment, “AChE activity was inhibited in E. fetida in two 

studies, one of which resulted in muscular paralysis that directly impacted earthworm burrowing 

capabilities.”

In the first study, carbaryl stock solution was prepared in acetone and water to yield final 

concentrations of 1, 2, 4 and 8 parts per million. Five earthworms were individually exposed for 

5, 10, 20, 40 and 80 minute intervals in a 50ml beaker containing 2.0ml of various 

concentrations of test solution. The researchers asserted the test concentrations used in the study 

were close to expected residues in the soil without any evidence or analysis as proof. They also 

used higher concentrations to exert significant inhibition of AChE activity and loss of burrowing 

in earthworms for establishing a dose effect “correlationship”. These higher exposures occurred 

after the individual worms were rinsed in tap water, their borrowing rate was measured, they

were rinsed again, then placed back into the solution. Needless to say this systematic dosing in a 

pesticide solution does not match any exposure levels that could result from the application of 

ultra-low volume sprays.

While the significant reduction in the ability of worms to burrow in soil was clearly evident at 

the lowest test concentration (1 ppm) and the earliest period of exposure (5 min), all worms were 

alive and fully recovered to normal behavior (no tremors, efficient burrowing) 18 hrs.

post-exposure to 1 ppm carbaryl.

The second study cited by the commenter measured AChE responses in earthworms exposed to 

carbaryl on filter paper and in a soil media. APHIS has previously noted the difficultly 

extrapolating between filter paper toxicological tests to actual exposure scenarios relevant to the 
Grasshopper Program treatments. While the AChE inhibition reached significance after one day 

of exposure to 0.48 mg/kg carbaryl, the researchers did not conclude there was a reduction of 

burrowing capacity. Pure carbaryl was used as a liquid solution, while Zoril 5 was applied as a 

powder spread on the soil. Zoril 5 was thus more abundant on the superficial soil fraction, and 

was immediately in contact with the animals, whereas pure carbaryl penetrated into the soil and 

probably became bioavailable later. APHIS would also like to note the tested application rate of 

17.8 pounds per acre carbaryl 5% powder formulation (Zoril 5), that was estimated to result in a 

concentration of 4.29 mg/kg was nearly twice the maximum Grasshopper Program carbaryl bait 

rate and had no effect on earthworm AChE activity or the lysosomal membrane stability of 

E. andrei.

Comment 136

APHIS received the following comment, “In addition to earthworms, carbaryl negatively 

affected collembola population abundance and reproduction.”

The first and second studies cited by the commenter did not investigate carbaryl or collembola 

(Panda and Sahu, 2004, and Stepić, et al., 2013). The third paper cited used carbaryl as a toxic 

standard for comparison of the effects of other pesticides (Larson et al., 2012). The researchers 

applied carbaryl at a rate of 8.17 lbs. a.i./acre. Researchers conducting the fourth study cited by 

the commenters (Potter et al., 1990) made two applications of carbaryl at the same rate of 8.17 

lbs. a.i./acre, 16 times the maximum rate used by the Grasshopper Program in ultra-low volume 

sprays. The Grasshopper Program only makes one application per year. Therefore this study 

used 32 times the carbaryl rate as the program. In addition, the foliar spray of ultra-low volume 

carbaryl over rangeland is unlikely to result in subsurface soil concentrations comparable to the 

direct turfgrass application made in this study.

The next study cited by the commenters (Joy and Chakravorty, 1991) investigated carbaryl 

toxicity to collembola. Adult specimens of Cyphoderus sp. and Xenylla sp. and Lancetoppia sp. 

were exposed to soils saturated with solutions ranging from 0.5 to 10 ml/l. Although they noted 

the standard agricultural doses of carbaryl 50 WP was 6.25 ml/l, the researchers did not provide 

a sufficient description of their methods for APHIS to make a valuable comparison of the 

exposure rates of the collembola in the experiment to potential exposure levels resulting from 

Grasshopper Program treatments.

The commenters cited another study to suggest carbaryl effected collembola reproduction. Three 

nominal concentrations of carbaryl (1, 4 and 7 mg/kg) in soil chemical behavior and toxicity 

were investigated at different temperatures. After 15 days from soil spiking, it was observed that 

carbaryl concentration in soil decreased to 30% and 33% of the initial concentration at the 

temperature extremes of 8 °C and 28 °C, respectively, and 22.8% of the initial concentration 

under a 20 °C temperature regime. The collembola survival and reproduction were 

significantly affected at 4 and 7 mg/kg concentrations, approximately 4 and 7 times greater than 

hypothetical soil concentrations resulting from Grasshopper Program ultra-low volume sprays 

(see previous comments for estimations parameters).
Comment 137

APHIS received the following comments, “Carbaryl also negatively impacted Prostigmata mites, 

and Tiphia vernalis, a wasp that feeds on scarab beetle larvae in the soil.”

In the first study cited carbaryl applied at a rate of 8.18 lbs. a.i./acre, greater than 16 times the 

Grasshopper Program’s maximum rate, as a toxic standard for comparison of various pesticide 

control efficacy. The effects on oribatid and mesostigmatid mites was not surprising or 

comparable to exposure levels resulting from applications of carbaryl ultra-low volume sprays.

The commenters are mistaken, in that the research cited did not find effects 

on Tiphia vernalis (Helson et al., 1994).

Comment 138

APHIS received the following comment, “Carbaryl can be particularly toxic to ground-nesting 

bees, like Andrena erythronii, Bombus terrestris, and Bombus terricola.”

The commenters cited a toxicology study where carbaryl was applied topically to the thorax of 

the bees to investigate lethal doses and determine the concentration values in units of μg a.i./g 

body weight and of μg a.i./bee. This dosing method is not comparable to any exposure scenario 

resulting from the Grasshopper Program treatments using ultra-low volume sprays. APHIS 

would like to note that of the six insecticides tested, carbaryl had the second lowest relative 

toxicity, rather than as the commenter characterized being particularly toxic to ground-nesting 

bees. The researchers noted their study does not suggest an inherent, physiological relationship 

between size and pesticide susceptibility, and they further suggested that bumble bees may be at 

relatively little risk from carbaryl, contrary to the commenter’s suggestion of particular toxicity 

to Bombus terricola. The researcher’s elaborated carbaryl previously was not found to have

significant effects on bumble bees, citing Hansen and Osgood (1984). 

The acute effects of carbaryl on B. terrestris were investigated for ingestion and topical contact 

in another cited study. The researchers found the calculated hazard ratio for oral exposures of 

carbaryl (309) was below the mean (1399) and the median (381) of the 14 pesticides tested and 

reported. Carbaryl was not found to be toxic through topical exposure at the “highest dose 

advised on the label.” The hazard ratio values permit only a comparative evaluation between the 

different active compounds tested.

Comment 139

APHIS received the following comment, “Carbaryl caused 100% mortality 

in Nomia melanderi when exposed to field-rate pesticide residues 3 hours post-application, 97% 

mortality with 8 hours post-application, and 78% mortality 2 days post application. Carbaryl was 

more toxic than DDT.”

APHIS does not use DDT during Grasshopper Program treatments and does not agree that the 

relative toxicity to carbaryl is a concern. The study cited by the commenter did not test carbaryl 

toxicity on bees, but rather included data from earlier studies. The application rate of carbaryl 

emulated in the earlier studies was I.0 lbs. 80% wettable powder per acre, approximately twice 

the maximum ultra-low volume rate used by the Grasshopper Program. APHIS found the 
literature did not provide sufficient details for a reasonable comparison of the carbaryl 

application methods and rates for additional effects analysis.

Comment 140

APHIS received the following comment, “Bombus impatiens colony vitality (as measured by 

colony weight, worker weight) and the number of workers, honey pots, and brood chambers was 

reduced following carbaryl exposure.”

The researchers noted the confinement of the bee colonies within cages represent a worst case 

scenario in that the workers were caged on the sprayed plots for two or four weeks. Wholecolony consequences of a smaller proportion of the workers foraging on insecticidecontaminated weeds in an open system likely would be less severe. In addition, the researchers 

explained extent to which an insecticide is hazardous to pollinators is determined by its inherent 

toxicity as well as the formulation and manner in which it is applied (Stark et al. 1995). For 

example, pollen contamination, which can decimate honey bee colonies, may be exacerbated 

by wettable powder or microencapsulated formulations that have high affinity for binding to 

pollen (Johansen et al. 1983).

APHIS would also like to note the direct application of carbaryl to turfgrass at rates ten times 

greater (5.44 lbs. a.i./acre) than the maximum rate used by the Grasshopper Program (0.5 

lbs. a.i./acre) is not comparable to ultra-low volume foliar spray treatments.

Comment 141

APHIS received the following comment, “In a laboratory study, chlorantraniliprole negatively 

inhibited the enzymes acetylcholinesterase and glutathione-S-transferase in Eisenia fetida.”

As previously stated, the Grasshopper Program will not be using chlorantraniliprole in Arizona 

during 2020. Therefore any chlorantraniliprole exposure scenarios which the commenter is 

concerned about are not relevant at this time.

Comment 142

APHIS received the following comment, “Chlorantraniliprole negatively 

affected Folsomia candida (collembola) reproduction.”

As previously stated, the Grasshopper Program will not be using chlorantraniliprole in Arizona 

during 2020. Therefore, any chlorantraniliprole exposure scenarios which the commenter is 

concerned about are not relevant at this time.

Comment 143

APHIS received the following comment, “Microscopic examination in an avoidance test 

revealed that the collembola were paralyzed from the chlorantraniliprole treatment and couldn't 

migrate, clarifying an observed avoidance at 1 mg/kg, but no avoidance at any higher 

concentrations. The authors note that chlorantraniliprole may be more toxic to non-target 

arthropods closely related to insects than to other soil invertebrates.”
As previously stated, the Grasshopper Program will not be using chlorantraniliprole in Arizona 

during 2020. Therefore, any chlorantraniliprole exposure scenarios which the commenter is 

concerned about are not relevant at this time.

Comment 144

APHIS received the following comment, “In the field, ground-nesting bumble bees (Bombus 

impatiens) treated with chlorantraniliprole consumed less pollen than control bees.”

As previously stated, the Grasshopper Program will not be using chlorantraniliprole in Arizona 

during 2020. Therefore any chlorantraniliprole exposure scenarios which the commenter is 

concerned about are not relevant at this time.

Comment 145

APHIS received the following comment, “Staphylinidae (Coleoptera) population abundance was 

slightly but significantly suppressed.”

As previously stated, the Grasshopper Program will not be using chlorantraniliprole in Arizona 

during 2020. Therefore any chlorantraniliprole exposure scenarios which the commenter is 

concerned about are not relevant at this time.

Comment 146

APHIS received the following comment, “After one application of diflubenzuron, myriapoda

populations were nearly eradicated (73% reduction), gamasina mites were reduced by 40%, 

and uropodina mites were reduced by 57%. Diflubenzuron treatment reduced the populations of 

oribatid mites, prostigmata mites, and soil arthropod larvae, mostly comprised of coleoptera 

and diptera, by nearly 15%.”

The cited research does not suggest Grasshopper Program applications of diflubenzuron will 

result in significant impacts to soil microfauna. The researchers applied diflubenzuron to plots 

and investigated the effects on Collembola, Insecta, Myriapoda, and 4 groups of mites for 6 

months. The observed taxa abundance fluctuated seasonally, but for a majority of taxa no 

significant differences were noticed between the control and exposed plots. The total number of 

microarthropods was insignificantly lower in exposed groups. While myriapods were the only 

taxon that was close to extinction after a single exposure to diflubenzuron the pesticide was 

applied directly to the soil at a rate four times greater than the maximum conventional 

application rate used by the program. The researchers noted their data proved that soil has some 

buffering capacity, and this fact should always be taken into consideration when estimating the 

risk for the environment.

Comment 147

APHIS received the following comment, “In a field study, collembola populations were 

negatively affected by diflubenzuron and did not recover for one and a half years. The 

earthworms, Dendrobaena rubidus and Lumbricus rubellus were reduced in plots treated with 

concentrations of diflubenzuron at half the recommended field rate. Gamasid and oribatid mite 

populations were additionally reduced, and oribatida were observed migrating into deeper soil 

layers to avoid the pesticide.”
The commenters have cited a study where the researchers applied two treatments of 

diflubenzuron wettable powder directly to the forest floor at a rate 37% higher than the 

maximum rate used by the Grasshopper Program. Contrary to the characterization of the 

research findings presented by the commenter, the mean population size of earthworms did not 

differ significantly during the potential effect phase between control and the 137% the 

Grasshopper Program rate treatment plot. The populations of the enchytraeid species 

E. buchholzi, E. minutus, E. norvegicus and M. clavata did not respond to this 137% treatment of 

diflubenzuron applied twice per growing season. While the number of oribatids decreased after 

the application of the insecticides in all experimental plots including the control, these 

differences were only significant in the plot were diflubenzuron was applied directly to the forest 

floor at a rate nearly 14 times greater than the maximum Grasshopper Program rate.

Where Brachychthoniid populations declined significantly in the diflubenzuron treated plots, the 

reductions were in part compensated by changes in numbers of the dominant genus Oppiella.

The researchers explained the half-life of diflubenzuron in soil is reported to range from 1 to 27 

days, which was borne out by their data. Therefore, residue accumulations in the organic layer 

is unlikely if diflubenzuron is only applied once per year.

The researchers acknowledged that there could be several potential reasons for differences in 

populations of soil invertebrates between the study plots. First, the plots could differ independent 

of any treatment. APHIS agrees this is a reasonable interpretation because of the small sample 

sizes during the pre-application, potential effect and early recovery data recording phases (I.e. 

four plots including the control, five sample dates, two replicates, n=10). The testing of natural 

variation during the 9 month pre-application phase may not have been sufficient. They decided 

to interpret deviations as a response to a treatment, if numbers in the potential effect phase were 

different to those in the other phases in the same plot and to the control in the same phase.

Comment 148

APHIS received the following comment, “Diflubenzuron treatment resulted in a total loss in 

brood production of male Bombus terrestris, and 100% inhibition of egg hatching success and 

larval growth. Transovarial transport and accumulation of the pesticide in deposited eggs 

explained the total loss of reproduction. Abnormal cuticle formation, which can lead to 

mechanical weakness and death, was observed in dead larvae that worker bees were observed 

removing from treated nests.”

The commenters have cited a study where the B. terrestris was directly dosed with diflubenzuron 

to test acute toxicity. Adult worker bees were exposed via contact by topical application and 

orally via drinking sugar water and by eating pollen. For contact application, 50 μL of the 

aqueous concentration was topically applied to the dorsal thorax of each worker with a 

micropipette. The worker bumblebees were also provided diflubenzuron treated sugar-water for 

drinking for 11 weeks. Bumblebees can also be exposed orally to pollen sprayed until saturation 

with a diflubenzuron concentration. Both the sugar water and pollen were supplied for unlimited 

oral consumption.

While APHIS acknowledges the effects of acute diflubenzuron exposures on the egg hatching and 

larval stages of bumble bees is a concern, the direct dosing conducted by the researchers is not 
comparable to any exposure levels that could result from the Grasshopper Program 

diflubenzuron ultra-low volume spray treatments.

In addition, APHIS would like to note, no acute mortality was observed after topical application, 

nor after oral exposure to treated sugar-water or treated pollen. In all cases, the number of dead 

worker bees in the treated nests over a period of 11 weeks was not above that of the control 

groups using water (0–10%).

Comment 149

APHIS received the following comment, “Multiple studies have observed AChE inhibition in 

earthworms when malathion was applied. Malathion effected the sperm count and viability and 

testicular histology of male E. fetida at sublethal concentrations, potentially impairing population 

abundance.”

APHIS agrees with the commenter that the main acute poisonous effect of malathion is the 

inhibition of the enzyme acetylcholinesterase, and acute poisoning such as was carried out by 

the researchers with direct exposures to high concentrations of the pesticide could occur in many 

types of organisms including earthworms. The direct dosing of earthworms to validate their use 

as toxicological test organisms does not mimic any exposure scenario resulting from the 

Grasshopper Program use of ultra-low volume sprays of malathion.

To further illustrate the disparity between exposures resulting from laboratory toxicity tests and 

grasshopper suppression treatments APHIS would like to note the lowest tested concentration 

was 80 mg/kg of soil. The Grasshopper Program applies malathion ultra-low volume spray at a 

rate of 0.62 pounds active ingredient per acre. If a cubic foot of rangeland soil weighs 75 

pounds, 1 acre (43,560 ft.2) of soil two inches deep would weigh 544,500 pounds, or 246,981 

kilograms. The maximum rate used by the Grasshopper Program to apply malathion as an ultralow volume spray is 0.62 pounds (281227 mg) active ingredient per acre. Therefore, the 

maximum concentration of 1.14 mg malathion spray per kg of soil could result from program 

applications. However, this analysis assumes none of the foliar spray settled on vegetation, and 

the malathion instantly absorbed into the top two inches of soil. This hypothetical soil 

concentration resulting from ultra-low volume sprays should not be compared in a risk analysis 

with the 80 mg/kg tested for sub-lethal effects in the laboratory.

As previously stated, the Grasshopper Program will not be using malathion in Arizona during 

2020. Therefore any malathion exposure scenarios which the commenter is concerned about are 

not relevant at this time.

Comment 150

APHIS received the following comment, “In addition to AChE, the biochemical biomarkers 

glutathione-S-transferase, and catalase were also inhibited by malathion in studies 

with Eisenia andrei. Malathion has also been observed to negatively affect the reproduction 

of E. andrei.”

The commenters have cited research that confirms malathion inhibits AChE in earthworms. 

While APHIS does not dispute this effect, the agency doubts such effects could result in 
significant impacts. Notably the researchers found the inhibition period suggests lengthening of 

retreatment intervals to 45 days is the appropriate conclusion from the study. APHIS only makes 

one suppression treatment per year to grasshopper infested rangeland.

As previously stated, the Grasshopper Program will not be using malathion in Arizona during 

2020. Therefore any malathion exposure scenarios which the commenter is concerned about are 

not relevant at this time.

Comment 151

APHIS received the following comment, “Malathion had a severe effect on AChE activity 

in Drawida willsi. Growth, casting activity, and respiration of D. willsi was negatively affected 

by malathion treatment and did not recover for 75, 60, and 30 days, respectively.”

The commenters have cited research that confirms malathion inhibits AChE in earthworms. 

While APHIS does not dispute this effect, the agency doubts these biomarker effects could result 

in significant impacts.

The study cited by the commenters described malathion’s recommended agricultural dose as 2.7 

to 4.0 kg a.i./ha and calculated the equivalent 1.5 to 2.22 mg a.i./kg soil, which APHIS would 

like to note are comparable to the concentration estimation provided above. However the toxicity 

results for a single dose of malathion were reported for a concentration of 2.2 mg ai/kg which is 

equivalent to double the dose of 4.0 kg a.i./acre, nearly six times the application rate used by the 

Grasshopper Program. 

As previously stated, the Grasshopper Program will not be using malathion in Arizona during 

2020. Therefore any malathion exposure scenarios which the commenter is concerned about are 

not relevant at this time.

Comment 152

APHIS received the following comment, “In addition to AChE, the biochemical biomarkers 

glutathione-S-transferase, and catalase were also inhibited by malathion in studies 

with E. andrei. Malathion has also been observed to negatively affect the reproduction 

of E. andrei.”

The commenters have cited two toxicology studies where earthworms were placed in test tubes 

lined with malathion saturated filter paper to determine acute effect concentrations, extrapolated 

from the biomarker, AChE reduction. The dosing methods and units of ug a.i./cm2 are not 

comparable to any exposure levels that could result from the application of malathion ultra-low 

sprays by the Grasshopper Program. The study cited by the commenter did not make any 

conclusions regarding malathion affecting reproduction of E. andrei.

As previously stated, the Grasshopper Program will not be using malathion in Arizona during 

2020. Therefore any malathion exposure scenarios which the commenter is concerned about are 

not relevant at this time.
Comment 153

APHIS received the following comment, “In a lab test rating the toxicity of 45 pesticides 

to E. fetida, malathion was ranked moderately toxic with an LC50 of 114.4 ug/cm.”

The study cited by the commenter was a comparison of the toxicology of 45 pesticide to 

determine the LC50. These studies exposed earthworms to varying concentrations of carbaryl to 

determine toxicological endpoints. Based on the extremely high doses, the impact to the survival 

of earthworms was not only unsurprising, but the object of the studies. APHIS would like to note 

this laboratory dosing procedure is not comparable to any exposure scenario resulting from the 

use of malathion ultra-low volume sprays by the Grasshopper Program.

As previously stated, the Grasshopper Program will not be using malathion in Arizona during 

2020. Therefore any malathion exposure scenarios which the commenter is concerned about are 

not relevant at this time.

Comment 154

APHIS received the following comment, “Malathion caused a 40% decrease in survival of the 

ground-nesting bee, Nomia melanderi.”

The study cited by the commenter did not test malathion toxicity on bees, but rather included 

data from earlier studies. The application rate of malathion emulated in the earlier studies was 

I.0 lb. of emulsifiable concentrate per acre, significantly greater than the maximum ultra-low 

volume rate used by the Grasshopper Program. APHIS found the literature did not provide 

sufficient details for a reasonable comparison of the malathion application methods and rates 

for additional effects analysis.

As previously stated, the Grasshopper Program will not be using malathion in Arizona during 

2020. Therefore any malathion exposure scenarios which the commenter is concerned about are 

not relevant at this time.

Comment 155

APHIS received the following comment, “The EAs an agency action subject to this consultation 

requirement, must be prepared “concurrently with and integrated with environmental impact 

analyses . . . required by . . . the Endangered Species Act of 1973.”

The commenter has again confused the two EAs prepared by APHIS for the Grasshopper 

Program in Arizona with other environmental risk analysis documents. See comment/response 

156.

Comment 156

APHIS received the following comment, “In order to properly provide information to the public 

for commenting on the EIS and the EAs, the section 7 process should be completed prior to the 

completion of NEPA. APHIS must ensure that consultation addresses all species and critical 

habitat that could be directly and indirectly affected by the proposed project.” The comment also 

states that APHIS has not complied with its responsibilities under Section 7 of the ESA.
Concerns were raised about specific species in Arizona such as the desert tortoise, Chiricahua 

leopard frog, southwestern willow flycatcher and other listed and sensitive species.

As stated in the final EIS APHIS has completed programmatic consultation 

with the National Marine Fisheries Service (NMFS). APHIS has reinitiated programmatic 

consultation with NMFS to include chlorantraniliprole. In the interim APHIS will consult with 

NMFS at the State level if there is a proposal to apply chlorantraniliprole. The NMFS 

consultation does not apply to species in Arizona since there are no federally listed species 

under NMFS jurisdiction however the information was provided in response to comments 

regarding the final EIS. APHIS submitted a programmatic biological assessment to the FWS in 

2015. APHIS is currently working with the FWS to update and complete the biological 

assessment and receive concurrence. The intent of the programmatic biological assessment is to 

provide consistent mitigation measures for listed species that may co-occur with Program 

treatments. In the meantime consultations with the FWS are still being completed at the local 

level prior to any treatments. No APHIS treatments are made in States without prior 

concurrence from the FWS or NMFS regarding federally-listed species. This information is 

also summarized in the final EIS.

Local FWS Section 7 consultations were entered into prior to the DRAFT EA# AZ-20-01 and AZ20-02. The letters of concurrence from FWS regarding the local site specific biological

assessment was included as appendix 7 of Draft EA# AZ-20-02. This letter is dated February 10, 

2020. Consultations regarding Tribal Lands in Arizona, come from the Region 2 office. The 

letter of concurrence is signed by the FWS Region 2 office in Albuquerque, NM. At the time of 

the Draft EA#AZ-20-01 the Letter of Concurrence was written and the lead biologist indicated 

verbally that the letter was sent for signature. This letter of concurrence from FWS was dated 

April 1, 2020. The Final EA# AZ-20-01 and AZ-20-02 will again have the letters of concurrence 

cited in the appendix 7 of both EA’s.

APHIS consulted with the FWS on federally-listed species that may occur within the county or 

areas where grasshopper and Mormon cricket treatments may be required. APHIS works 

closely with the FWS to determine the application of protection measures and where those 

measures should be applied prior to any treatments. APHIS also evaluated the potential direct 

and indirect impacts to non-target species which is summarized in the final human health and 

ecological risk assessments for each insecticide. 

Comment 157

APHIS received the following comment, “The EA’s mysteriously state that “the proposed 

APHIS program will not likely adversely affect this species.” These conclusive statements, 

unsupported by documentation of any manner of ESA consultation, fail to meet the ESA’s 

requirements. In EA AZ-20-01, Appendix 7, where the letter of concurrence is supposed to be 

displayed, there is simply a blank page. Obviously, this fails to constitute ESA compliance. In 

EA AZ-20-02, there is a letter of concurrence, but FWS fails to comply with its duties to concur 

on species where APHIS comes to a no effect conclusion, despite APHIS’s lack of expertise in 

these species, and thus the letter does not provide any ESA coverage for these species.”
Local FWS Section 7 consultations were entered into prior to the DRAFT EA# AZ-20-01 and AZ20-02. The letters of concurrence from FWS regarding the local site specific biological

assessment was included as appendix 7 of Draft EA# AZ-20-02. This letter is dated February 10, 

2020. Consultations regarding Tribal Lands in Arizona, come from the Region 2 office. The 

letter of concurrence is signed by the FWS Region 2 office in Albuquerque, NM. At the time of 

the Draft EA#AZ-20-01 the letter of concurrence was written and the lead biologist indicated 

verbally that the letter was sent for signature to the Regional Office. This letter of concurrence 

from FWS was dated April 1, 2020. The Final EA# AZ-20-01 and AZ-20-02 will again have the 

letters of concurrence cited in the appendix 7 of both EA’s.

Comment 158

APHIS received the following comment, “Because the site specific project is vague and fails to 

describe the breadth of cumulative effects it cannot comply with the ESA or NEPA. Any 

discrepancy between the project described in the EAs and the documents provided to the U.S. 

Fish and Wildlife Service must be rectified.”

APHIS believes that the site specific information described in the draft EA is adequate to allow 

completion of Section 7 compliance with the FWS. Information discussed in the draft EA is also 

shared with the FWS during consultation so there is no discrepancy between actions described in 

the EA and other documents.

Comment 159

APHIS received the following comment, “APHIS would unlawfully be making an irreversible or 

irretrievable commitment of resources if it allows insecticide application on rangeland 

grasshoppers and/or Mormon crickets to occur prior to receipt of a final biological opinion from 

FWS. APHIS will run afoul of its Section 7 ESA requirements if it chooses to move forward, and 

it will also likely violate the ESA’s prohibition against the take of endangered species as 

described by Section 9 of the statute if it moves forward with this project prior to properly 

completing its Section 7 duties. Even where there is a letter of concurrence, APHIS would still 

fail to comply with the ESA because informal consultation does not authorize the incidental take 

of federally-listed species nor does it authorize the adverse modification or destruction of critical 

habitat, and the letter of concurrence fails to articulate any rationale for the buffers.”

APHIS has been able to complete informal consultation with the FWS regarding the APHIS 

Grasshopper Program at the State level. Formal consultation has not been required since the 

FWS has concurred with the APHIS determinations of not likely to adversely affect, including 

any associated critical habitat. Since APHIS has complied with Section 7 through informal 

consultation APHIS has not violated Section 9 of the ESA, nor has formal consultation been 

required resulting in a biological opinion.

Comment 160

APHIS received the following comment, “Even where the letter of concurrence applies, it does 

not apply to all the pesticides APHIS is considering using in the EAs, and as FWS notes in the 

letter of concurrence.” The comment goes on to state that any actions taken in counties not 

covered, using pesticides not cover, or that may take listed species will be in violation of the 

ESA.
The APHIS Grasshopper Program does not use any pesticides not covered under FWS 

concurrence. If it is not listed in the concurrence letter it is not used in the field. APHIS does 

not treat in counties not covered in the action areas proposed to the FWS during Section 7 

consultation.

Comment 161

APHIS has received the following comment, “Grasshopper spraying in or near riparian areas can 

decrease prey populations for these species (SWFL and YBCO) as well as produce chronic sublethal effects as a result of drift or ingesting pesticide through the insects they consume.”

Protective measures were developed during the lengthy local FWS Section 7 consultations

for each of the 37 T&E species and species of concern within proposed treatment areas. APHIS 

protective measures were determined using the FWS Recommended Protection Measures for 

Pesticide Applications in Region 2 of the U.S. Fish and Wildlife Service” (USFWS 2007). The 

FWS letters of concurrence agree with our determinations. In Arizona, the use of ground 

equipment for localized treatments reduces the risk of drift. 

Comment 162

APHIS received the following comment, “There is no data on how carbaryl, dimilin, or 

malathion affects reptiles 182 with APHIS attempting to use bird toxicity data to assess reptiles. 

This is a badly flawed extrapolation. Because there is no data on the effects on reptiles, and 

because the desert tortoise is significantly imperiled across its range, precautionary principle 

would dictate that no application of these insecticides occur within desert tortoise habitat.”

APHIS relied on available laboratory and field reptile toxicity data in final human health and 

ecological risk assessments that were prepared for each Program insecticide. APHIS agrees 

that there is uncertainty in the use of avian toxicity data as a surrogate for reptile sensitivity.

However in cases where no reptile toxicity data is present avian data can be used to approximate 

potential hazards. APHIS notes this uncertainty in its pesticide human health and ecological 

risk assessments that were completed to support the final EIS. This is also consistent with other 

agencies that have used this avian toxicity data as a surrogate for assessing hazards to 

chemicals. 

In Arizona, the critical habitat for the Mojave population of the Desert tortoise was addressed 

during the local FWS Section 7 consultations. In order to protect this T&E species and critical 

habitat, APHIS agreed with FWS to exclude all known critical habitat from APHIS proposed 

action areas in Arizona. Thus, APHIS actions would have no effect on this T&E species. This is 

documented in the FWS Letter of Concurrence, dated February 10, 2020, appendix 7 of Draft 

EA# AZ-20-02.

Likewise, the proposed species, Sonoran Population of the Desert tortoise, was discussed during 

local Section 7 consultations. APHIS agreed to exclude known habitat of this population during

FWS discussions to protect this sensitive species and habitat.
Comment 163

APHIS received the following comment, “While carbaryl is expected to pose minimal risk to 

aquatic and terrestrial plants, application to wet foliage or periods of high humidity may cause 

damage to tender foliage.”

The comment may be referring to the use of liquid formulations of carbaryl. As stated 

in previous responses, Arizona is not proposing the use of liquid formulations of carbaryl. There 

is a very low risk to have enough wet foliage or high humidity to produce enough dew in 

Arizona. In addition available toxicity data suggests that effects to terrestrial plants would not 

occur at the proposed use rates.