United States

Department of

Agriculture

Marketing and

Regulatory 

Programs

Animal and 

Plant Health 

Inspection 

Service

Asian Longhorned 

Beetle Program

Environmental Assessment,

February 2000
Asian Longhorned Beetle

Program 

Environmental Assessment,

February 2000

Agency Contact:

Mike Stefan

Operations Officer

Plant Protection and Quarantine

Animal and Plant Health Inspection Service

U.S. Department of Agriculture

4700 River Road, Unit 134

Riverdale, MD 20737-1236

Telephone: 301-734-8247

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

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

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

disabilities who require alternative means for communication of program 

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

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

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

Room 326-W, Whitten Building, 14th and Independence Avenue, SW,

Washington, DC 20250-9410 or call 202-720-5964 (voice and TDD). USDA

is an equal opportunity provider and employer.

Mention of companies or commercial products in this report does not 

imply recommendation or endorsement by the U.S. Department of Agriculture 

over others not mentioned. USDA neither guarantees nor warrants the 

standard of any product mentioned. Product names are mentioned solely 

to report factually on available data and to provide specific information.

This publication reports research involving pesticides. All uses of pesticides 

must be registered by appropriate State and/or Federal agencies before they 

can be recommended.

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

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

properly. Use all pesticides selectively and carefully. Follow recommended 

practices for the disposal of surplus pesticides and pesticide containers.
Table of Contents

I. Need for Proposal ........................................... 1

A. Introduction ............................................... 1

B. Purpose and Need for Action .................................. 1

II. Alternatives ................................................ 3

A. No Action ................................................ 3

B. Injection Application Alternative ................................ 3

C. Injection Application and Bark Treatment Alternative .................. 5

III. Environmental Consequences .................................. 6

A. Potential Impacts ........................................... 6

 1. No Action .............................................. 6

 2. Injection Application Alternative .............................. 7

 3. Injection Application and Bark Treatment Alternative ............... 11

IV. Agencies, Organizations, and Individuals Consulted ................ 15
1

I. Need for Proposal

A. Introduction 

The U.S. Department of Agriculture (USDA), Animal and Plant Health

Inspection Service (APHIS), is proposing a program to apply

prophylactic treatments for the control of the Asian longhorned beetle,

Anoplophora glabripennis (Motschulsky). The program change is

necessary to enhance program operations in reduction of the potential for

damage from this major pest of trees. The Asian longhorned beetle 

bores into and kills a variety of tree species (including species of maple,

elm, chestnut, birch, poplar, and willow). This nonnative pest has the

potential to spread to other areas of the United States and cause

extensive losses to ornamental and commercial tree species. It has been

detected at several locations in the Chicago and New York City

metropolitan areas, and ultimately may be found in other areas as well. 

Under APHIS' National Environmental Policy Act Implementing

Procedures, 7 CFR Part 372, the proposed action is a class of action for

which an environmental assessment (EA) is normally prepared. This EA

considers the potential effects of the proposed action and its alternatives,

including no action.

North America has abundant forest resources. Most logs and lumber

imported into the United States have historically been limited to those

from the forests of Canada. Increased trade has resulted in more

frequent and greater quantities of logs and lumber (including solid wood

packing materials (SWPM)) entering the United States from other parts

of the world. Various plant pests, such as the Asian longhorned beetle

from China, can occur on or in these unfinished wood products. 

Protection of the forest resources of the United States from damage by

foreign pest species is part of the mission of the U. S. Department of

Agriculture, Animal and Plant Health Inspection Service (APHIS) and

exclusion of those pest species is the most effective method of 

preventing the losses associated with new pest infestations.

B. Purpose and Need

Increased trade and the resultant increased opportunities for invasion by

alien agricultural pests have placed the United States and its agricultural

economies at substantially increased risk in recent years. In particular, a

number of infestations and interceptions of exotic forest wood boring

insects have been associated with SWPM from the People’s Republic of

China. Outbreaks of the Asian longhorned beetle (Anoplophora

glabripennis), a destructive pest of maple and other hardwoods, were 
2

first detected in New York in 1996, and in Chicago, Illinois in 1998. In

addition, four genera of wood borers (Anoplophora, Ceresium,

Hesperophanes, and Monochamus) have been intercepted in shipments

from China that were delivered to warehouses in 11 States. The effects

of those outbreaks and interceptions, and of control and regulatory

measures to deal with them have been costly from environmental and

economic perspectives. 

APHIS has responsibility for taking actions to exclude, eradicate, and/or

control plant pests including Asian longhorned beetle, under the Plant

Quarantine Act (7 U.S.C. 151-165, 167), the Organic Act of 1944 

(7 U.S.C. 147a), and the Federal Plant Pest Act (7 U.S.C. 150dd). 

APHIS has been delegated the authority to administer these statutes and

has promulgated Quarantines and Regulations (7 CFR 319), which

regulate the importation of commodities and means of conveyance. 

The current exclusion and eradication program consists of various

regulations designed to require treatment of SWPM from China and

eliminate the Asian longhorned beetle by removing infested trees 

detected in the United States. This approach is currently effective at

preventing new infestations from wood products imported from China,

but it has not effectively contained the Asian longhorned beetle within 

new areas of infestation. Removal and destruction of infested host trees

is time-consuming and expensive. Effective elimination of the beetle by

removal of infested host plants depends upon early and timely

identification of infestations in trees and cutting before the beetle can

spread to nearby host plants. Small infestations that are detected early

may be eradicated easily, but the infestations in New York and Illinois

have spread further and become difficult to eliminate. Therefore, the

program seeks prophylactic methods to prevent infestation of healthy

trees from adult beetles in the vicinity of presently infested areas. The

systemic nature of the insecticide applications being considered may also

eliminate beetle larvae from recent infestations of living trees. Field 

tests for several treatments have been conducted in China that indicate

that the prophylactic treatments are suitable for cost-effective use in

control of the beetle in the United States.

This EA has been prepared in compliance with the National

Environmental Policy Act of 1969 (42 U.S.C. 4321-4327 (NEPA)) and

its implementing regulations. 
3

II. Alternatives

APHIS considered carefully three alternatives to respond to the need for

better methods to contain Asian longhorned beetle infestations: (1) no

action; (2) injection application alternative (the proposed action); and (3)

injection application and bark treatment alternative. Each is described

briefly in this section and the potential impacts of each are considered in

the following section.

A. No Action 

Under the no action alternative, APHIS would continue the current

control program against Asian longhorned beetle. Some control

measures could be taken by other Federal or non-Federal entities; those

actions would not be under APHIS’ control or funded by APHIS. In the

absence of more effective measures to contain and control Asian

longhorned beetle, the gradual spread of the beetle in the vicinity of the

New York and Illinois area infestations would be expected to continue. 

This would result in continuing costs for detection and removal of 

infested host trees. Although the anticipated spread to surrounding areas

is limited, the cumulative environmental and fiscal costs could be

considerable and would increase commensurate with the expansion of 

the area infested by the Asian longhorned beetle.

B. Injection Application Alternative (Proposed 

 Alternative)

Under this alternative, program control measures would be expanded to

include applications of systemic insecticide treatments against Asian

longhorned beetles by various injection methods. Applications would

include either soil injections or injections directly into the lower plant 

trunk just above the roots of uninfested trees. Current regulations 

require any infested trees discovered by the program to be marked and

cut in a manner that eliminates all life stages of the beetle. The intent of

the injection treatments would be to facilitate transport of the active

ingredient of the pesticide from the site of application (root zones) to 

active tree growth areas where the beetles would be expected to feed

and lay eggs. 

Uninfested trees adjacent to those infested by Asian longhorned beetles

would receive priority for prophylactic treatments, but applications could

be made to any tree at high risk in the Chicago or New York

metropolitan areas. The desired period of protection for the uninfested 

trees coincides with the period of beetle activity and is primarily between
4

June 15 and October 15. The limited testing of possible insecticides 

with systemic activity against woodboring beetles indicates that

imidacloprid (Merit 75WP®) shows the most promise for effective use in

an operational program. The preliminary testing indicates some activity 

of imidacloprid against adult beetles as they feed on small twigs and

possibly when the female beetles deposit their eggs. Some reports have

indicated that imidacloprid provided 2 years of control against target

insect pests. 

The soil injections of imidacloprid are made with a power soil injector at

100 to 250 pounds per square inch (psi) pressure to a depth of 4 to 

8 inches in a circular pattern surrounding the tree trunk. Application 

rates for soil and trunk injections are determined by the diameter of the

trees at breast height (DBH). A minimum of 2 quarts of formulation

(1.89 g Merit 75WP®) are required per inch of DBH. The treatment

holes will generally be made in a circle that is 3 feet (ft) from the trunk. 

A second circle may be treated at 6 ft from the trunk as required for

larger trees based upon the DBH. The systemic uptake by the tree will

require approximately 2 months, depending upon the tree species, soil

conditions, and the time of year when the application is applied. 

Optimal timing of soil treatments are during the fall 

(September/October) or during the spring (March/April) when systemic

transport of insecticide could occur throughout the tree. Soil 

applications are less effective when drought conditions result in dry soil. 

These applications do require large amounts of water to ensure that the

mixture will be taken up by the tree. The advantage of soil injection is

that the placement occurs where exposure to people or nontarget wildlife

is unlikely and the applicator may proceed to treat the next tree without

need to limit access (unlike Mauget® trunk injections) to the area after

application is made. Imidacloprid has moderate water solubility, but it

has low soil mobility due to adsorption to soil particles, so exposure to

humans by these applications is unlikely unless the soil under the trees is

dug up. If pavement covers the soil under trees in urban areas, soil

injection treatments may not be an option and the trunk injections

described in the next paragraph may be selected. 

The trunk injections of imidacloprid are applied through 4 milliliter 

Mauget® trunk injectors. One injector is required for every 2 inches of

DBH of the tree. Holes are drilled at a 45 degree angle to the trunk for

dispenser placement in the root flares close to the soil (2 to 6 inches

above the soil wood line). Dispensers are activated by hitting the top

with a rubber mallet or pressing with hands. The injection takes a few 

hours and the area must be secured to prevent disturbance of injectors

during this period. Maintaining security is important both to ensure 
5

effective treatment and to prevent public exposure to imidacloprid from

contact with dispenser contents. Preliminary tests indicate that this

method may provide some control of newly developing larvae as well as

feeding adult beetles. The systemic movement of imidacloprid from these

injections in the tree occurs shortly after treatment to 3 weeks. This is

much less than the 2-month period required for soil injection, but the

insecticidal properties may not last as long in the tree as with soil

injection. Unlike soil injections, no water or mixing tank are needed. 

This method is preferable in areas where soil under trees is paved and

where high water table or related problems prevent soil injection. 

Damage to trees from drill holes could be a problem, but the primary

concerns would relate to pests other than insects (e.g., fungal pathogens). 

The precise placement of injection treatments and the security during

applications preclude many potentially adverse environmental effects. 

The physical environment is minimally impacted because imidacloprid

residues are restricted to the tree or the treated soil. Neither persistence

nor bioaccumulation problems are expected from injection treatments. In

the unlikely event that a person did receive imidacloprid exposure from

the injection applications, their exposure would not be expected to result

in any adverse effects to human health as long as the individual did not

have allergies or other sensitivity to the formulation. There are some

nontarget species that occur in trees and soil under trees that could be

affected by these treatments. In particular, invertebrates directly exposed

to imidacloprid would be expected to have high mortality, but the effects

on local populations of these species are anticipated to be temporary. 

Some local insectivores could have to increase their foraging efforts. 

Other nontarget wildlife are not expected to be affected.

C. Injection Application and Bark Treatment 

 Alternative

Under this alternative, treatments would include the testing of the 

injection techniques as described above. In addition, this alternative

would also include various bark treatments in control of Asian 

longhorned beetle. Bark sprays are made to target the adult beetles as

they feed on the twigs and deposit eggs. These applications would need

to be made during or just prior to the adult flight period between June 15

and October 15 to provide effective control. The efficacy results from

these treatments are readily observable, but the residual action depends

upon environmental conditions. More than one bark treatment could be

required during the long flight season of the Asian longhorned beetles. 

Complete coverage of the bark is necessary for these treatments to be

effective, therefore, a hydraulic type sprayer with high pressure 

(400-800 psi) is required for pesticide application. Adequate coverage
6

of the bark may be difficult for 60 to 80 foot trees. Unlike some 

injection treatments, these applications to bark have not been shown to

have systemic action against larvae. Large amounts of water are used for

this type of application and limiting runoff is important. The potential 

bark treatment insecticides include formulations of permethrin,

chlorpyrifos, bifenthrin, and deltamethrin. 

The bark treatments have several environmental consequences to the

physical environment, human health, and nontarget species that would 

not be expected for injection applications. Phytotoxicity to some plants

could be an important issue, particularly where bark applications must

penetrate through the foliage. Air, soil, and water quality could be

affected by contamination from drift and runoff from bark treatments. 

The full coverage increases the likelihood of exposure to humans and

other nontarget species with increased risk of adverse effects from these

treatments. Other than direct effects on invertebrates, toxicity to birds

from the full coverage treatment is likely, particularly with chlorpyrifos. 

Unlike the injections that limited residues to locations within the tree 

and below the soil surface, detectable residues from bark treatments are

likely to occur at locations where humans and animals could be exposed. 

In addition to higher potential exposure from bark treatments, the 

relative toxicity of the bark treatment insecticides is comparable to or

higher than that of imidacloprid. These potential adverse effects from 

the bark treatments greatly exceed those from injection applications. 

III. Environmental Consequences

A. Potential Impacts

There are potential impacts from each of the alternatives being

considered. The pest risk from Asian longhorned beetle is an important

consideration for all alternatives. Potential program impacts arise from

each of the chemical treatments, but most of the treatment impacts are 

not expected to be substantial. The potential affected areas are primarily

urban parks and residential areas. Exposure to humans and potential

effects to human health are primary considerations addressed for 

program actions in these locations. 

1. No Action Environmental impacts that could result from APHIS’ implementation of

the no action alternative relate primarily to pest risk effects if current

eradication programs fail to contain and eliminate new infestations of

Asian longhorned beetle. The lack of available treatments for 

controlling this insect pest restricts control measures to removal of 

infested trees and elimination of potentially available host plants. The 
7

adverse effects from removal of individual plants may be minimal, but 

the Asian longhorned beetle has many host plants and the potential

impacts from ongoing removal of infested vegetation are considerable

with expansion of the infested areas. The potential establishment of 

Asian longhorned beetle would be associated with damage to and loss of

valuable ornamental and commercial trees, spread of the beetle to other

areas of the country with resultant damage to and loss of trees, loss of

associated forest products (e.g., maple syrup), and private or

uncoordinated use of pesticides to control the pest with associated

adverse impacts to the environment (the physical environment, human

environment, and nontarget species). The wide distribution of host 

plants suggests the danger of spread across much of the country with

increases in damage and losses commensurate with the spread. The

damage and losses could result in reductions in private property value. 

Structural lumber could be internally damaged, resulting in risk of

structural failure, losses to property, and injuries to humans. The 

damage and losses to commercial trees would lower the value and

production of timber and tree products such as maple syrup. The

changes in the composition and age structure of forests resulting from no

action could have long-term effects on the ecological relationships in the

forested areas. There could be losses in recreational revenue to some

areas from diminished amount of certain activities such as fall foliage

visitations. There would be losses of valuable shade and ornamental 

trees in residential areas. The potential for future quarantine restrictions

on the export of logs and nursery stock increases if more effective 

control and eradication methods are not developed. The primary

environmental consequences of this alternative are increased risk of pest

spread and elevated environmental risks from uncoordinated application

of pesticides to limit damage from the Asian longhorned beetle. The

potential adverse impacts from selection of this alternative are

considerably greater than those anticipated for the other alternatives.

2. Injection 

 Application 

 Alternative

The environmental consequences of this alternative relate primarily to 

the potential for decreased pest risk and to potential environmental 

effects from treatment methods. Effective operational implementation of

this prophylactic injection application by the program could help to

protect susceptible host plants and assist in the efforts to contain and

eradicate Asian longhorned beetle from infested areas of Illinois and 

New York. This would alleviate concerns about continuing expansion 

of the current eradication program. It could prevent the damage to and

loss of many valuable ornamental and commercial trees, loss of

associated forest products (e.g., maple syrup), and private or

uncoordinated use of pesticides to control the pest with associated 

adverse impacts to the environment (the physical environment, human

environment, and nontarget species).
8

Effective injection applications would provide an alternate means of

protection for trees to the present program practice of removing and

destroying newly infested trees. The insecticide proposed for application

against beetles is imidacloprid. Determination of the potential

environmental impacts from this alternative requires analysis of toxicity,

environmental fate, exposure, and associated risks from imidacloprid

injections. 

Toxicity

Imidacloprid is a systemic, chloronicotinyl insecticide. The mode of 

toxic action is unique and involves direct binding to the acetylcholine

receptors. This binding causes a nerve impulse to be sent, but

acetylcholinesterase is incapable of removing imidacloprid from the site. 

The receptor site becomes overstimulated and is eventually blocked. 

The nicotinergic site of action is more prevalent in insects than in higher

organisms, so the toxicity is selectively more toxic to insects. 

The acute toxicity to mammals is moderate. The acute oral median 

lethal dose of imidacloprid to rats is 450 milligrams per kilogram 

(mg/kg) body weight. The acute dermal median lethal dose to rats of

imidacloprid is greater than 5,000 mg/kg. Imidacloprid is not irritating 

to eyes or skin and is not a skin sensitizer. Signs and symptoms of

intoxication include fatigue, twitching, cramps, and muscle weakness

including the muscles for breathing. 

Chronic toxicity from imidacloprid is low. The systemic No Observed

Effect Level (NOEL) for a 2-year feeding study of male rats was 

5.7 mg/kg based on increased thyroid lesions observed at the next higher

dose, 17.1 mg/kg. The reproductive NOEL determined from a 

3-generation reproduction study of rats was 8 mg/kg based upon

decreased pup body weight at 20 mg/kg. Imidacloprid may be weakly

mutagenic. Test results were negative for mutagenicity in all but two of

the 23 laboratory mutagenicity assays conducted. The positive assays

were for genotoxicity in Chinese hamster ovary cells and changes in

chromosomes in human lymphocytes. The U.S. Environmental 

Protection Agency (EPA) has classified imidacloprid in “Group E” in

regards to carcinogenic potential. This indicates that the submitted

studies provide evidence of noncarcinogenicity for humans. 

Toxicity to other wildlife varies considerably. Imidacloprid is 

moderately to severely toxic to birds. It is severely toxic to bees, but it is

not considered a hazard to bees when used as a seed treatment. 

Imidacloprid is practically nontoxic to fish and slightly toxic to daphnia. 
9

Environmental Fate and Exposure

Imidacloprid residues from injection applications are not expected to

persist in the environment. The vapor pressure of imidacloprid is low 

and little volatilization to the atmosphere is expected. Imidacloprid is

moderately soluble in water and the half-life in water exceeds 31 days at

pH 5, 7, and 9. Soil injection applications and trunk injections are not

expected to result in any transport of imidacloprid to groundwater or

surface water. Imidacloprid adsorbs to soil particles and has low

mobility. The half-life in soil varies from 48 to 190 days depending 

upon the organic matter, ground cover, and plant uptake. The systemic

action of Imidacloprid from trunk injections would be expected to carry

the residues to other locations within the plant. 

Adherence to the pesticide label and standard operating procedures

ensures that exposures are minimal. The injections would not be

expected to routinely result in any exposure to humans except the

program applicators. The required protective gear and safety precautions

minimize applicator exposure. The applicators ensure that the Mauget®

injection dispensers are not disturbed during injection and the dispensers

are removed from the drill holes when the application is complete to

prevent exposure to the public. The only route for potential exposure of

the public to imidacloprid is from the accidental scenario of a person

digging in the treated soil following soil injection applications. Much of

the compound would have adsorbed to soil particles and the actual

exposure to imidacloprid would be minimal. The injection applications

avoid exposure to most species of wildlife. The only species likely to be

directly exposed by these injections are those nontarget invertebrates

present in the treated soil or in the wood of the treated tree. Some

insectivores and scavengers could also be exposed to residues during

foraging activities in the soil below or in the bark of treated trees. The

exposures of these species to imidacloprid are expected to be light. 

Risk Assessment

The risk of adverse effects to environmental quality are minimal. The

imidacloprid from soil injections and trunk injections is not expected to

volatilize to the atmosphere, is not expected to be leached to 

groundwater, and is not expected to be carried to surface water except 

from heavy rainstorms. The soil and plant residues are expected to 

remain active for up to 2 years to protect the trees from infestation by 

Asian longhorned beetles. 

The risks to human health are minimal. The required protective gear and

safety precautions for applicators result in potential exposures much 

lower than any that could result in adverse effects. The anticipated 
10

margins of safety from the accidental exposure scenario where a person 

digs up the soil from the treated area under a tree are less than for the

applicators, but no adverse effects are anticipated for those individuals 

either.

Mortality from exposure would be expected for some invertebrates. The

populations of insects directly exposed to imidacloprid would be 

expected to decrease temporarily in the treatment area until the residues

decrease and recolonization occurs from surrounding areas. This 

recovery would be expected to occur more rapidly in the soil because the

compound would be readily taken up by the tree roots and residues would 

not persist in the soil. The insects exposed to residues in the trees would

require longer periods of time for recolonization. Although the prey for 

some insectivores would decrease in treated areas, the additional forage 

effort by these species is not expected to be increased greatly. The low

exposures to birds and insectivores foraging in the soil and tree bark are 

not expected to result in any adverse effects to those species. 

Other Issues

An effort was made by APHIS to determine what, if any, measures would 

be required for program compliance with the Endangered Species Act of

1973. The potential for exposure and any adverse effects was analyzed 

for those endangered and threatened species and their habitats within the

proposed program area. Based upon the findings of that analysis, it was

determined that the proposed program applications would have no effect 

on those species or their habitats. 

Consistent with Executive Order No. 12898, “Federal Actions to Address

Environmental Justice in Minority Populations and Low-Income 

Populations,” APHIS considered the potential for disproportionately high 

and adverse human health or environmental effects on any minority 

populations and low-income populations. The environmental and human

health effects from the proposed applications are minimal and are not 

expected to have disproportionate adverse effects to any minority or low

income populations. 

Consistent with Executive Order No. 13045, “Protection of Children 

From Environmental Health Risks and Safety Risks,” APHIS considered 

the potential for disproportionately high and adverse environmental 

health and safety risks to children. The program applications are made to

trees and soil below trees in urban parks and residential areas where 

children would be expected to play and climb trees. The program 

applicators ensure that the general public is not in or around areas being

treated, so no exposure will occur for Mauget® injection applications and the

only possible exposure could occur from a child playing in the treated 
11

soil under a tree. This accidental exposure scenario was analyzed and it 

was determined that no adverse human health effects would result to the 

child. Therefore, it was determined that no disproportionate effects on

children are anticipated as a consequence of implementing the preferred

alternative.

3. Injection 

 Application 

 and Bark 

 Treatment 

 Alternative 

The environmental consequences of this alternative related to the 

potential for decreased pest risk and injection applications are the same as

those described for the injection application alternative. The bark 

treatments, however, have considerably greater potential for adverse 

effects to the physical environment, human health, and nontarget species. 

The insecticides being considered for bark treatments include permethrin,

chlorpyrifos, bifenthrin, and deltamethrin. 

Effective bark treatments require application to all surfaces of bark on the 

tree. The logistics for complete bark treatment of tall trees (60 to 80 foot) 

are challenging and would require ladders or tall cherry pickers to be 

close enough for good treatment, even with the high-pressure hydraulic 

rig applicators used. These treatments could result in considerable drift,

particularly on windy days. Runoff from these applications to nearby 

water is likely, particularly if a rainstorm occurred shortly after treatment. 

Chemicals used in the bark treatments are expected to undergo 

degradation (photolysis or chemical breakdown) over time and could 

require more than one treatment to ensure good control during the period 

of June 15 to October 15 when the adult beetles are active. For example,

deltamethrin residues on some treated plants have been shown to decrease 

to below the detection limit within 10 days. The high visibility of these

treatments would be expected to draw the public’s attention to the actions 

and increase the potential for direct exposures.

Toxicity

The bark treatment insecticides are of two chemical classes. Chlorpyrifos 

is an organophosphate insecticide. Permethrin, bifenthrin, and 

deltamethrin are synthetic pyrethroid insecticides. Although both classes 

affect the nervous system, the mechanisms of intoxication differ. The 

mode of toxic action of chlorpyrifos occurs primarily through

acetylcholinesterase (AChE) inhibition. Inhibition of AChE results in an

accumulation of acetylcholine at the nerve synapse and continual 

transmission of nerve impulses. The mode of toxic action of the synthetic

pyrethroids occurs through effects on the sodium channels that stimulate 

nerves to produce repetitive discharges. Muscle contractions are 

sustained until a block of the contractions occurs. 
12

The insecticides all have moderate acute oral toxicity to mammals, but 

differ considerably in other known toxicological effects. The acute oral 

median lethal doses to rats range from 53.8 mg/kg for bifenthrin to 

430 mg/kg for permethrin. The systemic NOEL values range from 

0.03 mg/kg/day for chlorpyrifos to 5 mg/kg/day for permethrin. 

Reproductive and developmental toxicity from these compounds occurs 

only at much higher exposures. None of the insecticides are known to be 

skin sensitizers. Irritation to skin and eyes of rabbits from exposure tests 

was undetectable to slight. Mutagenicity tests have shown negative 

results (deltamethrin, permethrin) or both positive and negative results

(bifenthrin, chlorpyrifos). The carcinogenic potential of these insecticides 

vary considerably. Information about oncogenicity studies was not 

located for deltamethrin. EPA has classified chlorpyrifos as not 

carcinogenic. Permethrin is suspected of being a weak oncogen, but EPA 

has not determined carcinogenic potency for these borderline effects. 

Bifenthrin has been classified by EPA as a class C (possible human) 

oncogen. The cancer potency of bifenthrin was determined by EPA to be 

5.4 x 10-1 (mg/kg/day)-1 in human equivalents. 

The toxicity to nontarget wildlife depends upon the insecticide. All are

moderately toxic to mammals. Permethrin is very slightly toxic to birds. 

Bifenthrin and deltamethrin are slightly toxic to birds. Chlorpyrifos is

moderately to severely toxic to birds. All insecticides are severely toxic 

to terrestrial invertebrates. All are very highly toxic to fish and aquatic

invertebrates.

Environmental Fate and Exposure

The environmental fate of these insecticides applied to the bark of trees 

will depend upon the weather conditions. Chlorpyrifos is quite volatile 

and detectable amounts could be detected in the air. There could be some

permethrin residues in air following bark treatments, but these should 

dissipate readily. Bifenthrin and deltamethrin have lower vapor pressure 

and their residues would not be expected to remain detectable in air after

treatments are completed. None of these compounds are very mobile in 

soil and adsorption to soil organic matter would be expected. The halflife in soil varies from 1 to 2 weeks for deltamethrin to as long as a year 

for chlorpyrifos. All of these compounds readily adsorb to sediments in 

water, but residues may persist for several weeks. These bark 

applications would not be expected to contaminate water except possible 

drift or runoff from a heavy storm. These compounds are not systemic 

and little if any translocation within the treated plants is expected. 

Residues of these insecticides on the foliage and bark of treated plants 

may persist throughout the growing season (permethrin) or degrade within as

little as 10 days (deltamethrin). 
13

The bark treatments require complete coverage to be effective against 

Asian longhorned beetle. Penetration of the thick foliage to treat the bark 

of trees with a hydraulic rig indicates that all parts of the trees above the 

roots will have residues of the insecticide. The exposure from these

applications would be expected to be high to tree-dwelling invertebrates,

woodland birds, and squirrels. Drift and runoff to the soil below treated 

trees would expose some soil and ground-dwelling organisms, but most 

of these exposures would be more moderate. The human exposures 

would depend primarily upon contact with the tree. Program pesticide

applicators are required to wear protective gear and follow specific safety

precautions. These individuals would not be expected to have high 

exposures. An individual who decides to lean against a treated tree or 

climb without protective clothing could receive a high exposure, 

particularly if the treatment on the bark had not dried. 

Risk Assessment

The risks of adverse effects to environmental quality are greater for this

alternative than from the injection applications. The chlorpyrifos for 

some bark treatments could volatilize with detectable residues in the

atmosphere. Leaching to groundwater is highly unlikely, but drift and 

runoff could contaminate surface waters, particularly in areas where many

trees are treated and heavy rainstorms occur shortly after treatments. Any

need for additional treatments within the season when the beetle is active

makes the potential for contamination more likely. The plant residues are

expected to remain active for several months to protect the trees from

infestation by Asian longhorned beetles. Residues in soil may remain for

extended periods of time, particularly with chlorpyrifos.

The potential risks to human health from these bark treatment 

applications are considerably greater than from injection applications. 

The required protective gear and safety precautions for applicators result 

in potential exposures much lower than any that could result in adverse 

effects for all compounds except chlorpyrifos. The risks to mixers and 

loaders of chlorpyrifos are negligible, but exposures of hydraulic rig 

applicators exceed the regulatory reference value for both routine and 

extreme exposure scenarios. Adherence to proper protective gear and 

safety precautions by hydraulic rig applicators is important if chlorpyrifos

applications are to be considered. The anticipated effects to the general 

public could be adverse for some individuals. Exposures to the 

individual who leans against a treated tree or climbs without any 

protective clothing could be expected to have some symptoms of 

intoxication. Chlorpyrifos exposures from scenarios for soil 

consumption, contaminated runoff, and contaminated vegetation all 

exceed regulatory reference values, so adverse effects to the public from 
14

chlorpyrifos applications would be likely. Use of the other bark treatment

insecticides do not pose such high risks in these scenarios.

Mortality from exposure would be expected for many tree-dwelling and 

soil-dwelling invertebrates. The populations of tree-dwelling insects 

directly exposed to the bark treatments would probably decrease 

temporarily in the treatment area until the residues decrease and 

recolonization occurs from surrounding areas. This recovery would 

depend on the size of the area where trees were treated. Recovery would

take longer if all trees in a large city park were treated because the insect

populations in the surrounding areas might not include all species in the 

park trees. The quantitative risk assessment determined that populations 

of honey bees would be adversely affected by all of the bark treatments. 

The soil invertebrates exposed to runoff and drift would also have 

decreases in population. Their populations would recover more readily 

than tree-dwelling insects for some treatment chemicals (e.g., 

deltamethrin), but recovery could be slower for the insecticides that 

persist in soil such as chlorpyrifos. Effects on nesting birds from bark

treatments could be devastating, particularly with a severely toxic 

insecticide to birds such as chlorpyrifos. The quantitative risk assessment 

for chlorpyrifos applications predicted mortality for all nontarget species

analyzed except deer and dogs. Although squirrels and other treedwelling mammals are unlikely to receive a direct exposure, their 

exposures to these moderately toxic insecticide residues could result in 

various sublethal neurological effects that make them more susceptible to

predation. Likewise, any insectivores that forage on the treated trees or 

soil within the dripline could have exposures that result in adverse effects 

on potential survival. 

The environmental consequences and risks to the physical environment, 

human health, and nontarget species of this alternative are clearly greater 

than those from the injection application alternative. The logistics of 

treating all bark surfaces on tall trees make this alternative difficult to 

achieve, particularly for potential future operations in urban parks and 

along residential streets. The bark treatments can only ensure suppression 

of the adult beetle population for as long as residues persist and this may 

only provide protection for part of a season before retreatment is needed. 

Based upon these limitations, the injection application alternative would 

be more reasonable as a program control measure against the Asian

longhorned beetle. 
15

IV. Agencies, Organizations, and 

 Individuals Consulted

This environmental analysis was prepared and reviewed by APHIS. The

addresses of participating APHIS units, cooperators, and consultants (as

applicable) follow.

Win H. McLane

Section Leader

U.S. Department of Agriculture

Animal and Plant Health Inspection Service

Plant Protection and Quarantine

Insecticide and Application Technology Section

Building 1398

Otis ANG Base, MA 02542

U.S. Department of Agriculture

Animal and Plant Health Inspection Service

Plant Protection and Quarantine

Program Support

4700 River Road, Unit 134

Riverdale, MD 20737-1236

U.S. Department of Agriculture

Animal and Plant Health Inspection Service

Policy and Program Development 

Environmental Analysis and Documentation

4700 River Road, Unit 149

Riverdale, MD 20737-1238
Finding of No Significant Impact

Asian Longhorned Beetle Program

Environmental Assessment

February 2000

The U.S. Department of Agriculture (USDA), Animal and Plant Health Inspection Service (APHIS),

has prepared an environmental assessment (EA) for proposed program to contain the Asian longhorned

beetle. The proposed program is needed to improve containment and control of the Asian longhorned

beetle at locations in the United States where it has been detected. Previous regulations designed to

eradicate this pest have proven ineffective at eliminating the pest risk and containing new infestations. 

The EA, incorporated by reference in this document, is available from -

U.S. Department of Agriculture

Animal and Plant Health Inspection Service

Plant Protection and Quarantine

Domestic and Emergency Programs

4700 River Road, Unit 140

Riverdale, MD 20737-1236

The EA analyzed three alternatives - no action, injection application, and injection application and bark

treatment. Each alternative was determined to have potential environmental consequences. Based on

the information presented in the EA, I have selected injection application as the preferred alternative

because of the feasibility to implement in an operational program, the capability to meet the pest risk

reduction objectives, and the lower overall risk to human health and the natural environment than the

current operational methods.

APHIS considered the potential environmental consequences of each alternative. Based on analysis of

the environmental impacts, APHIS has determined that there would be no significant impact on the

quality of the human environment from the implementation of the injection application alternative. 

APHIS’ finding of no significant impact for this rule was based upon the application of standard

operating procedures for the applications and their expected environmental consequences, as analyzed

within the EA. APHIS will consult, where appropriate, with the U.S. Fish and Wildlife Service to

ensure that this program will have no adverse effects on endangered and threatened species. 

In addition, I find that the environmental process undertaken for these tests is entirely consistent with

the principles of “environmental justice” as expressed in Executive Order No. 12898 and that

implementation of the control measures will not result in disproportionately high and adverse human

health or environmental effects on any minority populations and low-income populations. Lastly,

because I have not found evidence of significant environmental impact associated with the proposed

program, I further find that an environmental impact statement does not need to be prepared and that

the program may proceed. 

Victor Harabin for 2/14/2000

Al Elder Date

Eastern Regional Director

Eastern Region

Plant Protection and Quarantine

Animal and Plant Health Inspection Service