Gypsy Moth:
California's Next Pesticide Emergency?

gypsy moth caterpillar gypsy moth trap gypsy moths

Ceremony and Peaceful Declaration Against the Gypsy Moth Spraying in the Ojai Valley:

Friday April 24th, 2009
8:30 a.m.
Lynda's Home
806 S. La Luna, Meiners Oaks, California
Please see the video about what happened last time the Department of Agriculture "visited" Lynda Rader's home, and violated her safety and civil rights by forcibly exposing her and others to pesticides.

On Saturday March 28, 2009, thugs from the California Department of Food and Agriculture showed up at the doors of residents in the Ojai Valley, with a sheriff and court order, frightened and intimidated elders, jumped locked fences, and forcibly sprayed people's homes with the insecticide Bacillus thuringiensis var. kurstaki (Btk) without warning.

Residents had been led to believe that they could refuse to have their properties sprayed, or that they could cover plants not susceptible to gypsy moths, and were advised to bring their pets inside during the spraying. They were not given adequate notice to do any of this, nor to make arrangements to be elsewhere themselves. Several residents had already been sickened by the previous round of spraying. Applications are being made every two weeks, over the course of several days, with drift between neighborhoods allowing for no relief.

See our OJAI GYPSY MOTH page for details

Chilling videos of the first round of spraying, with applicators disregarding manufacturer's warnings

To get involved in Ojai please contact Pesticide Free Ojai Valley (805) 646-4772

On September 2, 2008 a
Finding of Emergency was filed with the Secretary of State, establishing Alameda County as an eradication area for gypsy moths, effective immediately.

Alameda joins eleven other California counties already established as gypsy moth eradication areas under such findings of "emergency": Los Angeles, Marin, Nevada, Orange, Riverside, San Diego, San Mateo, Santa Barbara, Santa Clara, Santa Cruz, and Ventura counties.

This regulation gives the State the "authority to perfom detection, control and eradication activities against gypsy moth" in these counties.

A gypsy moth egg mass was found on a boat in Oakland August 20, but the gypsy moth that triggered the "finding of emergency" was trapped the next day, on August 21, in one of the little green traps you see all over California. Each trap contains a lure that emits chemical fumes into our environment. They often hang low on tree trunks, and in easy reach of small children, as can be seen in these photos. One of these traps had been ripped open, likely by one of the many curious children who congregate near where it was found. The black line in the top third of the broken trap is the lure, similar to the pesticide twist ties used in the light brown apple moth (LBAM) program. One of the chemicals it contains is disparlure, a synthetic "pheromone", classified as a pesticide when used with the intention of eradicating, but because of a bureaucratic loophole not classified as a pesticide when used to monitor or detect, even though the same chemical is used. The toxicity of disparlure has not been well studied, but it has been found to persist in the body for decades.

gypsymothtrap.jpg gypsymothtrapinside.jpg   

In California there have been a number of gypsy moth eradication programs throughout the decades, including quite recently in Marin County in 2001, Orange County in 2006, and Los Angeles County in Spring 2008. Part of Ventura County was formally quarantined on October 28, 2008, with the quarantine lasting for two life cycles of the moth, at least through the Fall of 2010, or longer if more moths are found. The State is proposing spraying Bacillus thuringiensis var. kurstaki on everything green in the spray zone, beginning March 9, 2009, with a minimum of 3 applications, 10-14 days apart. The public comment period ends March 4.

California Department of Food and Agriculture Gypsy Moth webpage

California Gypsy Moth Regulations - Current Quarantines and Eradication Areas

Environmental Assessment for Gypsy Moth program in Ojai Area in March 2009


Nonviolent Civil Disobedience Training
in Response to Gypsy Moth Pesticide Program

Sunday, March 8, 2009 - 2-6pm
followed by potluck
1273 South Rice Road, Ojai, CA 93023
(10th house on right by community pool)
(Please park on street outside of mobile home park - not inside)
For more info call (805) 794-1856

(Sponsored by Pesticide Free Ojai Valley, with support from Don't Spray California)


Other states already have extensive pesticide programs, especially in the northeast, where entire states are under quarantine (as of September 25, 2008: Connecticut, Delaware, District of Columbia, Maryland, Massachusetts, Michigan, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, and Vermont) and many others are under partial quarantines (Indiana, Illinois, Maine, North Carolina, Ohio, Virginia, and Wisconsin). Many, but not all states with quarantines have gypsy moth programs in place. Sometimes it is left up to the counties to implement programs themselves, or residents are encouraged to hire pesticide applicators.

Most Recently Updated Federal Gypsy Moth Quarantines

The most wide-spread gypsy moth pesticide program is the "Slow The Spread (STS)" program, an active partnership between the USDA (Forest Service and Animal and Plant Health Inspection Service (APHIS)), the Department of Interior National Park Service, and several other State and university programs. The states involved in the STS program are Illinois, Indiana, Kentucky, Michigan, Minnesota, North Carolina, Ohio, Virginia, West Virginia, and Wisconsin. Notice that not all of the quarantined areas are part of this program, nor are all states that are participating in it under quarantine.

"Slow the Spread" Pesticide Application Maps and Details

There are other states, which neither have quarantines, nor are part of the STS program, which have gypsy moth pesticide programs, or have left it up to local municipalities to implement them on their own. Trapping for the gypsy moths is done in most, if not all, states.

Annual Trapping Surveys Throughout the U.S.

Washington State has an active gypsy moth program, and applied pesticides in various areas for several years. Currently there are no official applications planned for 2009, nor were there in 2008, though extensive trapping, especially heavily in the areas where moths were found, continues. Oregon also has an active gypsy moth program, with pesticide applications made as recently as Spring 2008, and more planned for 2009 in Eugene.


Common pesticide products used in gypsy moth programs are Bacillus thuringiensis kurstaki (Btk) (Foray), disparlure (Disrupt), diflubenzuron (Dimilin), tebufenozide (Mimic, Confirm), Nucleopolyhedrosis virus (NPV) (Gypchek). Nurseries may use diflubenzuron, chlorpyrifos, carbaryl, acephate, cyfluthrin, phosmet, and spinosad.

Gypsy Moth Management - What is being done to control the gypsy moth?

USDA Approved Regulatory Treatments for Gypsy Moth for Nursery Use Only - 2008

The chemical industry has been selling Bacillus thuringiensis (Bt) and so-called "pheromones" as natural alternatives to pesticides, even though they all contain synthetics chemicals. The U.S. Department of Agriculture's National Organics Program, and the Organic Materials Review Institute, participating in the greenwash, allow both Bt and synthetic "pheromones" for use in organic agriculture, further diluting organic standards. If you google "non-chemical" options for gypsy moth control, the results are dominated by entries about Bt, even though every Bt product on the market contains synthetic chemicals, so-called "inert" ingredients, which are kept undisclosed, protected as "proprietary" by trade secret laws, are frequently even more toxic than the "active" ingredients listed on the label, and are specifically designed to interact synergistically to achieve greater toxicity than each chemical by itself.

Unidentified Inert Ingredients in Pesticides: Implications for Human and Environmental Health Cox and Surgan (pdf)

Chemically Induced Diseases: Synergistic Effects and Cumulative Injuries caused by Toxic Chemicals Alexander

The Impacts of Chemical Mixtures - Our Stolen Future

Synergism by Ingrid Pollyak
While government agencies and pesticide manufacturers downplay the importance of synergism, this essay, by a teen who homeschools, illustrates that understanding synergistic effects of chemicals does not require a Ph.D.

The dangers of chemical exposure are commonly downplayed with statements that the quantities of their poison are miniscule, with pesticide manufacturers and legislators going to great lengths to agree on just how much poison is legally acceptable to let loose on our environment. But in addition to synergistic and cumulative effects of chemical mixtures, some chemicals have a "nonmonotonic" dose-response, where reducing the dose of the chemical does not result in a reduction, but an increase in toxic effects.

The Low Down on Low-Dose Endocrine Disruptors

While undisclosed ingredients and chemical mixtures are serious, and often ignored issues, the recent focus on secret toxic "inerts" has mistakenly taken the focus off these "active" ingredients sold as "organic", "natural", and "biological". But Bt and disparlure have their own toxicity and unknowns:

Bacillus thuringiensis kurstaki (Btk)

Bacillus thuringiensis var. kurstaki, a bacteria mixed with secret "inert" chemical ingredients, has been sprayed both by air and by hand as part of gypsy moth programs. It is sprayed by air in many states, including Oregon and Washington, and was recently sprayed manually in Los Angeles County in 2008, and is planned for the Ojai area in Ventura County in March 2009.

Btk is implicated in gastro-intestinal illness and damage to the immune system. It has sickened thousands of people in New Zealand, prompting resistance which led to a People's Inquiry when their government was unresponsive.

Toxicological Profile for Bt by Northwest Coalition for Alternatives to Pesticides (NCAP) (pdf)

Toxicological Profile for Btk by Northwest Coalition for Alternatives to Pesticides (NCAP) (pdf)

No Spray Zone Overview of Btk (pdf)

(Unfortunately until recently No Spray Zone supported the use of disparlure as a "natural" alternative to Btk, and their webpage on the subject remains somewhat contradictory, and the NCAP tox profile for Btk takes a somewhat neutral position on synthetic "pheromones".)

In Ojai, the Btk product being sprayed from high pressure hoses is called DiPel Pro DF, it contains Bacillus thuringiensis var. kurstaki (Btk), in a 46% mix of undisclosed, proprietary chemicals. Pesticide information from the manufacturer, which is obviously not as reliable information as independent science, downplays the risk of harm of their product. But even their Material Safety Data Sheet, label, and Organic Certificate from the Organic Materials Review Institute, don't deny that there are serious risks:

According to the manufacturer's MSDS: "MEDICAL CONDITION AGGRAVATED BY EXPOSURE: Impaired respiratory function."

DiPel Pro DF Material Safety Data Sheet (MSDS)

In 2005, the U.S. Surgeon General reported that in the U.S. 1 in every 8 children has asthma, and the number of asthma sufferers had tripled to 20 million over the 25 years prior, that every day 12 people die and 5,000 emergency room visits are due to asthma. In 2007 a California Health Interview Survey estimated that as much as 13.6% of the Ventura County population was at some time diagnosed with asthma.

Asthma is just one of many conditions that impair respiratory function.

According to the label's First Aid instructions, on inhalation of the product, "if person is not breathing", call an ambulance and "give artificial respiration", and skin contact requires rinsing "immediately with plenty of water for 15-20 minutes".

DiPel Pro DF Label

The label clearly states:
"Do not apply this product in a way that will contact workers or other persons, either directly or through drift."

Disparlure (Gypsy Moth "Pheromone" - Mating Disruption)

Disparlure, the synthetic "version" of the gypsy moth pheromone used in "mating disruption", which is in the traps you see around town, and which is sprayed aerially as part of the STS program in many states, has been shown to persist in the human body for decades, as is outlined in these documents by scientist E. Alan Cameron, who, after he stopped working with this chemical, has continued to attract moths for many years:

Disparlure Persistence After 2 Years
Disparlure Persistence After 4 Years
Disparlure Persistence After 17 Years

Even the risk assessment of disparlure by the USDA Forest Service admits that the chemical may persist in a person's body for years after exposure. It also admits that there are "limitations in the availability of toxicity data on disparlure", that there have been no studies on the effects of disparlure on the immune, reproductive, endocrine, or nervous systems, nor whether it is carcinogenic.

In an outrageous display of arrogance in the light of such complete lack of safety data, the only "sensitive subgroup" of people at "special risk" that the Forest Service can imagine, might be "individuals who have an aversion to insects" because "individuals who are exposed to sufficient quantitites of disparlure and who live in an area in which gypsy moths reside will attract the moth."

Continuing the disinformation, the agency claims that "insect pheromones are generally regarded as nontoxic to mammals", but fails to clarify that the "pheromone" product they are using is a synthetic chemical designed to mimic a pheromone, and is, in fact, not an actual insect pheromone at all.

When it comes right down to it however, the Forest Service has to admit that disparlure is not nontoxic, that some toxicity has in fact been established ("acute exposure to disparlure has very low toxicity in mammals"). "Very low" is of course not a meaningful measurement, especially in regard to a chemical about which virtually nothing is known, and residents in sprayed areas are not acutely, but chronically exposed.

USDA Forest Service Disparlure Risk Assessment

"Pheromone" products are specifically designed to release their chemicals slowly over time, which ensures that the chemical saturates the environment, and exposure is constant, not for hours or days, but for weeks and months.

In the case of the light brown apple moth program the LBAM "pheromone" was in time released capsules. This brought with it an unexpected consequence for people who attempted to do clean up after the spraying: when people hosed down their yards, sidewalks, and cars, the water appeared to reactivate the mixture and people were exposed to an even stronger dose than they were from the dry capsules.

The disparlure product the USDA Forest Service uses in aerial applications is Disrupt II, manufactured by Hercon.

Disrupt II Label (pdf)

Disrupt II Material Safety Data Sheet (pdf)

The chemical mixture is embedded in polyvinyl chloride (PVC, vinyl) flakes, which is also not non-toxic, not in its manufacture, nor disposal, and not when ignited. In a list of accidental fires involving PVC, Greenpeace finds that it contributed to the start and/or spread of each fire, and "emitted life-threatening gases and chemicals":

"Besides the acidic hydrogen chloride, a wide variety of chlorinated and non-chlorinated organic chemicals evolve from PVC during high temperature pyrolysis and combustion: benzene, toluene, formaldehyde, chloroform, chlorinated biphenyls, dioxins and dibenzofurans, and many others. The emission during fires of benzene, chlorinated dioxins, and dibenzofurans - known carcinogens - appears to explain the high frenquencies of leukemia, laryngeal and colon cancer, and of the rare soft tissue cancers found in many firefighters at relatively young ages."

PVC flakes spread everywhere promise to cause toxic fumes during possible fires, be they wildfires, house fires, or campfires in the near future. Even the manufacturer's MSDS admits that when Disrupt flakes are burned "the hazardous decomposition products that will result because of incomplete combustion include carbon monoxide, other unidentified products of hydrocarbon degradation, Nox, low level cyanides and hydrogen chloride".

Hercon claims that the plasticizer used in this product is biodegradable, but no other details are disclosed. The most common PVC plasticizers are phthalates, which can be classified as biodegradable, but which have been linked to endocrine disruption and are possible carcinogens.

Disrupt II is used with a sticker agent, an adhesive, so that flakes can stick to foliage. STS uses Gelva Multipolymer Emulsion 2333. In a technical document about gypsy moth mating disruption the Forest Service makes public the Material Safety Data Sheet of the adhesive:

Gelva Multipolymer Emulsion 2333 MSDS (pdf)

The MSDS reveals that it contains vinyl acetate, a suspected carcinogen.

Vinyl Acetate Chemical Profile on Scorecard

The rest of the ingredients are vaguely named acrylic copolymer, and it is noted that the "specific chemical identity (including CAS No.) and/or concentration is being withheld because it is trade secret".

The chemicals in this mix may be doing their own damage to the tree canopy. During an evaluation of efficacy of different "pheromone" products, it was found that "either the sticker or pheromone from the flake appeared to have localized impact on leaf tissue as necrosis was observed at and immediately surrounding the contact point".

In addition to disparlure, some of the gypsy moth traps used by the Forest Service, the ones that look like milk cartons, also contain Vaportape strips, which contain dichlorvos (DDVP), an organophosphate which causes cancer, is a mutagen, and interferes with prenatal brain development. The name of the product itself implies that there are vapors, that volatilization, in other words chemical drift, is expected.

Toxicological Profile of Dichlorvos

Toxicological Description of Dichlorvos (in a toxicological profile of naled) (pdf)

Vaportape GM Insecticidal Strips Label (pdf)

Diflubenzuron & Tebufenozide (Insect Growth Regulators)

Diflubenzuron and tebufenozide are insect growth regulators (IGR), which are also mixed with undisclosed "inert" ingredients. There is great concern about the effects of IGRs on non-target species and full health and safety data on many of them are woefully lacking. Both diflubenzuron and tebufenozide can cause methemoglobinemea, which impacts the blood's ability to carry oxygen, and can result in the equivalent of suffocation.

Toxicological profile for Insect Growth Regulators

One of the breakdown products of diflubenzuron is p-chloroaniline (PCA), a probable human carcinogen.

Toxicological Profile for Diflubenzuron

Diflubenzuron - Dimilin Label

Tebufenozide - Mimic Label

Tebufenozide - Confirm label

Nucleopolyhedrosis Virus (NPV)

And the greenwashing continues with the "natural" product Gypchek, made from nucleopolyhedrosis virus (NVP), which appears to be specific to the gypsy moth. It is another sprayed pesticide product, and a perfect example of the hypocrisy of the pesticide industry: We're supposed to be concerned about caterpillars causing allergies with their hair, and a stinky nuisance with their poop, so they grind up the allergenic caterpillars, infected with the virus, mix them together with other chemicals, about which little is known, and spray it into our enviroment.

How Gypchek is Made

According to USDA Forest Service Risk Assessment for Gypchek

"Gypchek does contain substantial amounts (>80% by weight) of gypsy moth larvae parts, including hairs which are known to cause skin and respiratory irritation in humans. Based on the available animal data, there is clear evidence that Gypchek can cause eye irritation."

"Also as with most pesticides, the toxicity data base on Gypchek is extremely limited for certain types of biological effects for which the U.S. EPA does not routinely require testing – i.e., immunotoxicity, endocrine effects, and neurotoxicity."

Gypchek Label

Gypchek MSDS

Gypchek is mixed either with a surfactant, Carrier 038A (Abbott Laboratories), or with Lignosite AN (Georgia Pacific) and an adhesive, Bond (Loveland Industries), in molasses.

The risk assessment of the Forest Service continues to describe what is not known:

Gypchek is typically applied with a carrier, either Carrier 038A or a lignosulfonate-molasses carrier and another product, Blankophor, may also be included in Gypchek applications. Toxicity data on these adjuvants are extremely limited. Carrier 038A is a proprietary surfactant formulation. Surfactants are soap-like materials that can have a spectrum of toxic effects, most of which involve irritation to biological membranes. This appears to be the case for Carrier 038A. Toxicity data on this material is scant."

Carrier 038 MSDS

About Blankophor BBH (Burlington Chemical Co.), which is an "optical brightener", the Forest Service assumes "very low toxicity" based on "limited toxicity data".


Several organophosphates are used in nurseries against gypsy moths, chlorpyrifos, acephate, and phosmet. Chemicals in this class of chemicals are associated with serious health damage, including to the immune, reproductive, and nervous systems, as well as cancer.

Rachel Carson Council on Organophosphates


Chlorpyrifos is a broad spectrum organophosphate insecticide that damages the immune and central nervous systems, is associated with birth defects, and genetic damage. It contains other hazardous "inerts". One commonly found is xylene, which can cause hearing and memory loss, and leukemia. Chlorpyrifos is also toxic to beneficial insects, such as bees, ladybugs, and parasitic wasps, as well as fish, a wide variety of other aquatic organisms, and birds. Cats and other mammals have been poisoned, and even plants have been damaged by it. Chlorpyrifos is manufactured by Dow AgroSciences

Toxicological Profile of Chlorpyrifos (pdf) by Northwest Coalition for Alternatives to Pesticides (NCAP)

Chlorpyrifos Fact Sheet (pdf) by Chemical Watch and Beyond Pesticides

Farmworkers sue over Chlorpyrifos danger San Jose, July 2007

"Farm workers and advocate groups today filed a lawsuit in federal district court today against the Environmental Protection Agency to stop the continued use of a deadly pesticide called chlorpyrifos. Chlorpyrifos is a highly neurotoxic insecticide developed from World War II-era nerve gas. Exposure can cause dizziness, vomiting, convulsions, numbness in the limbs, loss of intellectual functioning, and death."


Acephate is a suspected carcinogen and mutagen, and exposure can cause impairment of the respiratory and central nervous systems, as well as cardiac responses. It is said to "metabolize into an unknown, but insecticidally-active, compound".

Acephate Toxicological Summary by the Rachel Carson Council

Acephate Chemical Profile on Scorecard

Toxicological Profile for Acephate 


Phosmet is another organophosphate which produces injuries typical of that class of chemicals, including being a possible carcinogen, and is implicated in damage to the central nervous system.

Toxicological Profile for Phosmet

Phosmet has also been suggested as a possible cause of Mad Cow Disease, as the onset in the U.K. coincided with ranchers being required to use phosmet on their cows, and the conventional explanation of the feed being the cause is not sufficient to explain the cases of Mad Cow in cows not fed the questionable feed.

Mark Purdey's Research into Phosmet as Causative Agent in Mad Cow Disease


Cyfluthrin is a synthetic pyrethroid, which is neurotoxic, linked to cancer, and reproductive harm.

Toxicological Profile for Cyfluthrin by Northwest Coalition for Alternatives to Pesticides (NCAP) (pdf)


Carbaryl is a carbamate, which is a carcinogen, mutagen, a hormone disruptor, does reproductive harm, and adversely impacts the immune system.

Toxicological Profile for Carbaryl by Northwest Coalition for Alternatives to Pesticides (NCAP) (pdf)


Spinosad is another pesticide that is "approved" for organics, representing further dilution of organics standards. It is considered non-synthetic, but also contains undisclosed synthetic "inerts".

Spinosad is implicated in the killing of non-target species, including honeybees. The Organic Materials Review Institute (OMRI) states that "Spinosad, while an improvement over some materials, is still fairly broad spectrum and not representative of an ecological approach." Spinosad is manufactured by Dow.

Review of Spinosad by Organic Materials Review Institute (pdf)

"These review comments should not be taken to be an evaluation of the patented formulation of Spinosad containing inert compounds." 


In the Northeastern U.S. gypsy moth pesticide programs are no longer "eradication" programs, but "slow the spread" programs. The USDA and other agencies involved admit that they can never get rid of the gypsy moth, but are merely delaying the inevitable. The clear implication is that there is no end in sight for these ongoing chemical assaults on people and wildlife. Instead of addressing the problem at the root, and figuring out how we might learn to live with this moth that is here to stay, they've firmly placed both feet on a toxic treadmill.

So what are the real issues with the gypsy moth?

The Indiana Department of Natural Resources gives several justifications for their pesticide program in their public relations power point presentation, with a dramatic slide show of hairy caterpillars and spongy egg masses:

* The caterpillars make a mess and smell bad.

The pesticides smell bad too, and are toxic. The USDA, which is funding the gypsy moth "Slow the Spread" program, also subsidizes Factory-scale dairy farms, which make a much greater stink, and cause illness.

* Caterpillar hair is an allergen.

When people complain about being poisoned by pesticides, they are often told that they are merely "allergic" to something in the pesticide. Agencies often find themselves compelled to preempt complaints in their "risk assessments", by admitting that some people may react to the pesticide, and claiming that those people are inherently unusually "sensitive", not sensitized by pesticide exposures. Many things cause allergies in people, but the government isn't shooting puppies on sight, or shutting down the peanut or soy industries.

* Trees are destroyed by defoliation.

Ironically one of the pesticides used in the gypsy moth program, the "pheromone" flakes, have been shown to cause necrosis of leaf tissue on contact. And the vast logging, which the Forest Service and other agencies are involved in, has done a great deal more defoliation than any moth ever will. In fact, in Pennsylvania the gypsy moth is being used as an excuse to log forests for profit:

Appeal planned over Governor Dick logging - Environmentalists say cutting down trees will put habitat in peril 11-30-08

Gypsy Moth is not real reason for clearcuts, herbicides and log money 1-18-09

Earth First activist Asanté Riverwind also questioned the motivations of the gypsy moth pesticide program by the Forest Service in Oregon and Washington State back in 2000: "In typical paradox, the USFS continues to plan timber sales in old-growth stands, while pretending to be concerned about the loss of critical old-growth habitat as a pretext for spraying. Another reason the USFS gives for the spraying is to protect humans from being irritated by the stinging hairs of TM caterpillars. Apparently wood workers, and loggers in particular, develop increased hypersensitivity and allergic reactions to the caterpillars mildly stinging hairs."

Insect infestations are a sign of imbalance, and most of these "pest" problems were caused by the agriculture industry, land-grabbing developers, and complicit forest mis-managers themselves.

Even conventional gardening expert Jeff Ball agrees that "When gypsy moths attack your trees and shrubs in sufficient number for you to begin to see damage, it is likely that the plants were experiencing some degree of stress BEFORE the moths appeared."

Sue Seppi of the Pennsylvania Group Against Smog and Pollution (GASP) describes how Entomophaga maimaiga, a fungus that had been introduced specifically to control the gypsy moth, but was believed not to have established in the U.S., may have in fact been quietly adapting in similar species that are also vulnerable to the pesticide applications. When fewer communities agreed to continue the ongoing pesticide programs, the fungus finally got a chance to thrive, and the gypsy moth caterpillars grew to half their usual size and died.

She is one of many who has described how "the gypsy moth population typically peaks and crashes, rising again over approximately a four year cycle. The greater the peak, the deeper the fall". Leellen Solter and Charles Helm of the Center for Economic Entomology and James Cavanaugh of the Illinois Department of Agriculture agree that "The gypsy moth is an 'outbreak species'; in infested areas the populations build up over a period of years, peak in very high densities, then decline strongly in the presence of natural enemies such as parasites and diseases." The West Virginia Division of Forestry finds that "In the northeastern states, gypsy moth populations peak every 8 to 11 years."

And scientists in Croatia studied the predictability of population dynamics of the gypsy moth in conjunction with climate data there, finding that "Strong Gypsy moth outbreaks occur regularly with a significant periodicity of 10.6 years. A peak in the Gypsy moth population density can be expected 5.2 years after the onset of the latency period, i.e., upon the ending of the previous gradation."

Asanté Riverwind points again to those who "manage" nature as a "resource" for profit, and suggests that it is in fact that "commodity-blinded mindset which calls natural cycles epidemics or catastrophic."

Rarely does anyone praise a hairy, hungry tussock moth, but a study has shown that gypsy moth outbreaks may actually slow the spread of Lyme disease, by way of chain reaction typical of nature's food web: As defoliation reduces acorn production, the white-footed mouse population is also reduced, because acorns are their primary food. Deer enjoy acorns as well, and thereby bring the ticks they carry to areas populated by the mice, which are a primary transmitter of Lyme disease.

Chain Reactions Linking Acorns to Gypsy Moth Outbreaks and Lyme Disease Risk

Asanté Riverwind points out that tussock moths "have an ancient role in a healthy forest ecosystem", and that defoliation can be explained as ecologically relevant by a study by scientist Catherine Parks, which "revealed that during drought periods when populations peak for the caterpillars of conifer needle eating species, the resulting defoliation helps trees to survive by reducing the amount of moisture lost through transpiration/evaporation. Instead of refoliating, the defoliated trees survive by using their energy to build up starch reserves in their roots. Of course, some trees die, providing nutrients for the soil, reducing competition for scarce moisture and creating homes for woodpeckers and numerous other species."

Research by the USDA's own scientists shows: Dead & dying trees stabilize biodiversity, logging ends it! And the same is true for pesticide use, which eliminates biodiversity and prevents natural, evolutionary processes to take place.


Non-chemical alternatives exist. They always do. Strangely enough our species managed to survive for centuries without intervention with synthetic chemicals.

Manual controls

Manual controls are simple: gypsy moths have one very predictable lifecycle per year.

Gypsy Moth Life Cycle

If it's the European version of the moth, the female can't fly, so they're easy to catch. Pupae can be removed, and egg masses can be vacuumed or scraped off, and destroyed.

Gypsy Moths laying eggs Gypsy Moth larvae hatching Gypsy Moth pupae

Caterpillars can be trapped on the way up the tree with plain, untreated burlap bands, then picked by hand or vacuum.

Burlap band 1 Burlap band 2  
Burlap bands are a type of trap, a non-chemical one. The traps the Ag Departments and Forest Service use emit chemical fumes constantly. They are designed to saturate the environment for long periods of time with disparlure. Also beware chemically treated burlap bands. Some people treat the burlap with various chemicals, particularly Eradicoat, which is made with permethrin, a neurotoxic, carcinogenic, endocrine disrupting, chromosome damaging insecticide, that is especially deadly to cats.

This is one kind of agricultural bug vacuum. Surely the USDA employs some scientist or tinkerer who could design one specifically for gypsy moths, their caterpillars and pupae, and out of reach egg masses.

Bug vacuum 1 Bug vacuum 2

Prevention & Longterm Ecological Balance

Planting and encouraging a wide diversity of trees and other plants, over time will balance the presence of both gypsy moths and its predators. Mono-cultures in agriculture and forests leave plants vulnerable to insects, while diversity supports a self-maintaining ecosystem. Where human activities have done ecological damage, it's only right to take responsibility and put effort into repairing it.

There are many lists of plants that gypsy moths prefer and others they avoid. For example, they prefer oak, apple, alder, aspen, basswood, birch, poplar, willow, hawthorn, hemlock, tamarack (larch), pine, spruce, witch hazel, linden, sweet gum trees, crabapple, cherry, beech, and hickory. They avoid ash, butternut, black walnut, sycamore, ferns, redbud, rhododendron, American holly, azaleas, bald cypress, locust, catalpa, dogwood, easter red cedar, elderberry, balsam fir, grape, horse chestnut, juniper, Kentucky coffee-tree, mountain laurel, mulberry, spicebush, sweet pepperbush, and viburnum.

These lists may be somewhat different depending on location, and they are hardly complete, but there is certainly plenty to work with.

Plant diversity contributes to keeping plants healthy, so they are more likely to be resistant to insect problems, as does keeping them watered appropriately for their needs, pruning as necessary, nourishing the soil with compost, mulch, and by leaving the natural mulch of fallen leaves and forest floor debris undisturbed, which also helps retain water, and never, ever using chemical fertilizers or pesticides. Diversity of plants also attracts a diversity of other organisms, including a wide variety of predators, and plantings and other actions should be done with the needs of predators of the gypsy moth in mind.

The hyperbole of some agencies which are pushing the pesticide programs, that there are no natural predators of the gypsy moth here, is simply ridiculous. There are similar native tussock moths, which have their place in the local food chain, and their predators will develop an appetite for such slightly more exotic fare, given the opportunity. Spreading chemicals all over the place robs the ecosystem of a chance to adjust and survive on its own.

While this document from the Michigan State University Extension lists a vast number of natural predators, it still pushes the toxic pesticide Bt. But even the conventional gardening expert Jeff Ball, who is not opposed to pesticide use either, advises that "Spiders and predator insects will kill many more gypsy moth caterpillars than a yardener armed with an insecticide ever will".

Plant diversity provides both forage and habitat for other organisms, and such deliberate offering of shelter can be supplemented by building houses for birds, bats, and even, as Ball explains, paper wasps, which "hunt gypsy moth caterpillars to provide food for their young. They will nest in your yard if you provide adequate shelter. Build some small boxes, about 6 inches square, and leave them open at the bottom. Paint them brown or black and fasten them to stakes placed in sunny areas. The wasps will build nests inside the boxes."

Among gypsy moth predators, of which there are also many other lists, there are various types of beetles, parasitic flies and wasps, spiders, daddy longlegs, ants, birds, squirrels, mice, shrews, chipmunks, foxes, racoons, skunks, voles, toads, frogs, and bats.

The life cycle, population cycles, and activities of the gypsy moth are really not terribly complex, and with proper timing of manual methods, a lot of control is possible, and this includes giving natural processes time to improve the situation. Hiring a large number of workers to go out at the proper times for handpicking, using bug vacuums, attaching and detaching burlap bands, scraping eggs and destroying them, and planting companion plants, are not impossible tasks. When we bring up such manual labor options we are usually told it's simply not feasible, but every time we do the math the money that is set aside for chemicals and equipment (not to mention overpaid bureaucrats) in this economic crisis would be better spent to pay the many unemployed workers living wages and health insurance for their families' survival.

A gypsy moth egg hunt from the USDA historical photo archive:

Gypsy Moth Egg Hunt

And if these insects really were "invading", the military certainly has the muscle to accomplish physical controls without poisoning the planet. Instead of waging war on other countries and cultures, soldiers could do something life affirming in nature, which does not have them returning home traumatized and chemically injured for a change. In fact, the Department of Defense already has an agreement with the USDA to conduct "forest insect and disease suppression on lands administered by the U.S. Department of Defense":

Agreement between the USDA and U.S. Department of Defense for Forest Insect Suppression

Unfortunately the military, with its long history of pesticide use, uses its muscle to apply more toxics, rather than manual controls. This power point presentation includes details of military involvement in gypsy moth pesticide programs on military land between 1986 and 2002:

Armed Forces Pest Management Board Power Point Presentation

"Invasion Biology" vs. Bio-Diversity:

The most urgent alternative we propose is a change in attitude towards "pests". The invasive species debate is an intense one among environmentalists. There are strong indications that the invasive species councils are sponsored, even established, by the pesticide industry, as documented by biologist David Theodoropoulos, author of "Invasion Biology: A Critique of a Pseudoscience".

Natives vs. Exotics - David Theodoropoulos
Overview of the critique of the invasives movement

Review of "Invasion Biology: A Critique of a Pseudoscience" by permaculture practitioner Toby Hemenway

Presentation by David Theodoropoulos videotaped at an East Bay Pesticide Alert / Don't Spray California event in 2008
San Francisco Chronicle's Bugman, Richard Fagerlund, summed it up nicely:

"To call the LBAM or any insect an invasive species is ridiculous. That would imply that they sat around and planned to invade and occupy our country. Humans are an invasive species. Bugs are opportunists. If we bring them into the country advertently or inadvertently, they will do the best they can to make a living here. No, the LBAM will not devastate California, but the pesticides used to attempt to control them may."

Even while engaging in management of so-called "invasive weeds", Professor Timothy Seastedt of CU-Boulder's Ecology and Evolutionary Biology Department questions the idea that ecosystems are static, or that they should be unchanging:

"Seastedt said atmospheric pollution, climate change, exotic species invasions, extinctions and land fragmentation have altered virtually every ecosystem on the planet. Managers and biologists should be nurturing so-called "novel ecosystems" -- thriving combinations of desirable plants and animals in habitats that have never occurred together before -- and developing new conservation strategies for them, he said."

Risk Assessment vs. The Precautionary Principle

Another relevant issue is the method by which these agencies come to decide that chemicals are necessary. They use the "risk assessment" model to come up with theoretical predictions of "what might happen if", citing a lot of corrupt science, often generated by the chemical industry, and then figure out how many of us are a "negligible" and "acceptable risk" of their toxic overkill. Those of us already chemically injured, and thereby particularly sensitized to chemicals, are always their acceptable risk, to be injured further, and again and again.

The opposite of risk assessment is the "precautionary principle", which in a nutshell says "better safe than sorry", and does not assume that lack of evidence that an action is dangerous implies safety, but places the burden of proof that it is in fact safe on those proposing the action. In California several municipalities have ordinances and resolutions invoking the precautionary principle.

Precautionary Principle Fact Sheet

Community Opposition

Resistance to pesticide applications has been ongoing for decades, often by isolated individuals or neighbors gathering in spontaneous response to a chemical threat to their community. In recent years the internet has facilitated greater connections between communities, and opponents to pesticide programs are reaching across regional boundaries to share research, resources, and action. When California residents were sprayed by the  LBAM program in 2007, solidarity for our struggle was expressed from as far away as New Zealand.

A common mistake among activists addressing toxics, one which continues to be a hard habit to break for many activists, is allowing the agencies that are pushing their pesticide programs to divide communities by intimidating them to compromise their own or someone else's right not to be exposed to toxics.

In the understandable panic over the specific chemical assault against them, many are willing to put up with anything other than what they are being threatened with, often substituting one assault for another. If they are threatened with aerial spraying, they'll negotiate ground spraying of the very same substances that drift into their homes. If it's ground spraying they're facing, they'll volunteer their own labor to hang traps and twist ties containing more of the same toxics. If they are being assaulted with one chemical they'll agree instead to another. If they live in an urban area, they send the crop dusters back to spray rural neighborhoods that are already surrounded by toxic agriculture.

They demand their right to a democratic vote on whether people want to be sprayed, trusting that the majority of their neighbors couldn't possibly be fooled by the propaganda of the agencies that are pushing the pesticides, all the while forgetting that large segments of the population do not have the right to vote at all, because they are immigrants, imprisoned, or below the age of 18. As a result, compassionate neighbors often end up selling each other out without ever meaning to do so, and movements leave the most vulnerable among them behind in the mad rush to negotiate compromises.

But should others have the right to vote to expose you to poison?

No strategy is more powerful than a true united front with uncompromising mutual solidarity, where communities stand up to common oppression, while maintaining political autonomy, which facilitates an opportunity for deeper discourse and learning from conflicting opinions. But no matter the differences, the grassroots stick together, and no one gets bargained to the wayside. A united front is most embodied by the slogan of organized labor: "An Injury to One, Is an Injury to All!"

The entire gypsy moth (and every pesticide) program is a problem. From trapping to detect and monitor, to the ground or aerial spraying of Btk or disparlure or other chemical cocktails, the chemical industry is making a killing (literally), and people are injured by every part of the program. With agencies that are obsessed with chemical "solutions", even allowing them to hang non-chemical traps, they are in effect potentially targeting neighborhoods with future pesticide programs against whatever they might find.

Below is a small sampling of resistance to gypsy moth programs, though not all have taken a firm stand against all chemical assaults, but fell into the trap of compromise, leaving themselves vulnerable to further assault:

Ojai, California, where applications of Btk began in March 2009:

A battle is brewing in Ojai, where residents were served with a court order to force access to their homes. Please see our OJAI GYPSY MOTH page for more details. To get involved, please contact:

Pesticide Free Ojai Valley

Patty Pagaling (805) 646-4772

"Pesticide Free Ojai Valley’s mission is to increase understanding and reduce public risks related to pesticide exposure in our community, through education, advocacy and public policy participation. We stand for a healthy living environment (public parks, wildlife areas, schools, and neighborhoods) in the Ojai Valley and beyond."

PFOV meetings are held the 1st and 3rd Monday of every month at 7pm
at Ojai Retreat, 160 Besant Road, in Ojai

Indiana, where applications of both disparlure flakes and Btk are part of an ongoing program:

A community in Kosciusko County is fighting back against plans to spray disparlure flakes in 2009.

Washington State, where applications of Btk have been made in recent years:

No Spray Zone, which unfortunately up until recently endorsed the use of disparlure, and confused the issue by calling this synthetic chemical "natural", which is still somewhat contradictory on their website, has otherwise done some very important work documenting the dangers of Btk, including showing the drift from ground applications right into people's homes, as well as photographing government trespass as an organic garden is sprayed against the will of its resident.

New Jersey

In Medford, New Jersey, beginning in 1982, when their daughter was battling cancer, the Enfield family protested against neighbors spraying carbaryl (Sevin), a carcinogen, against the gypsy moth. In 1990 the local police department took the family to court for displaying protest signs in their garden. The case was dismissed, and the Enfield's right to free speech was upheld by the court.

New York

In 1981 The New York Times noted "Resistance to Pesticide-Spraying Rises", with communities refusing to be sprayed by carbaryl or Bt, citing more resistance in New Jersey:

"Maybe we have to admit that we can't do anything about the gypsy moth  - sometimes nature beats us."


The Group Against Smog and Pollution (GASP) took a position against the spraying of Bt against the gypsy moth as early as 1998.

According to the Department of Conservation and Natural Resources, Bureau of Forestry, property owners have the option of objecting to spraying on their property, and may choose to stop spraying either at the boundaries of the property, or 500 feet around the property. Renters have no such rights, and of course 500 feet does not remotely address the issue of drift.

Form to Object to Spraying

, where disparlure was used in 2006 after residents opposed Bt:

In Travis County residents questioned whether there was indeed an infestation of gypsy moth at all, but unfortunately got pressured into accepting being sprayed with disparlure instead.


British Columbia

Society Targeting Overuse of Pesticides(STOP) has been opposing aerial spraying of Btk since 1992.

Cowichan Valley Stop Aerial Spraying Coalition has also opposed the spraying of Btk.
Toronto and Hamilton County residents expressed concerns about Btk being sprayed over their communities in Spring 2008. Their story prompted solidarity from neighbors in Mississauga, who had been sprayed previously, and from as far away as Vienna, Austria.

One remarked, "Since the gypsy moth does not pose a direct threat to human health, but the 'remedy' against it might, are we really spending our money wisely? Since the moth cannot be eliminated, is this spraying going to become another annual expense adding to our tax burden?"

Indeed, with polite audacity, "Households are being asked for a voluntary payment of $183 per to cover the cost of spraying."

Page last updated: 4/21/09