Science in Society Archive

Sex Hormone Sprays Halted over Cities But…

California embarks on an even more alarming pesticide eradication policy for a harmless moth. Sam Burcher

The good news is that officials have stopped aerial sprays of toxic pheromones over Californian cities (see Sex Hormones and City Life [1]), thanks to the campaign of scientists and citizens united by their concerns over health, social justice, and environmental protection.

 But, the State has reserved the right to spray rural areas such as farmlands, hills, ridges and forests where there is no protection for populations living there. The USDA has been forced to prepare an environmental impact report on rural areas, and is also appealing against the Court’s decision to stop the spray over urban populations in Monterey and Santa Cruz [2].

Synergistic effects of pesticides

Aerial spraying in the city will be replaced with mobile pesticide units, trucks spraying an insecticide Permethrin, a synthetic pyrethroid that the US Environmental Protection Agency has classified as a carcinogen because it inhibits the immune system and causes lung and liver tumours in mice [3].  It is extremely toxic and children are likely to be five times more susceptible to its effects than adults based on animal studies. Originally used in warfare, permethrin was combined with the nerve gas psyridostigmine bromide, and is a possible cause of health problems reported by 30 000 Gulf War veterans. Symptoms from exposure include aggressive behaviour, tremors, temperature rise and lack of co-ordination and learning ability.  It also affects male and female reproductive systems and causes chromosomal abnormalities.

Permethrin is toxic to honeybees and other beneficial insects, fish, aquatic insects and amphibians. A study that used a combination of permethrin and psyridostigmine bromide had an adverse effect on hens that increased further when other insecticides such as DEET were added.  A genetically modified bacterium Bacillus thuringiensis (Bt) is also used as a ground spray in urban areas. Bt is known to have allergenic effects on humans and animals in rural areas (see More Illnesses Linked to Bt Crops [4].) so there is concern about the synergistic effects of permethrin and Bt ground spray in backyards and city spaces.

Sterile moths released by air instead

The really bad news is that the latest act of war pending against the populations in California is the aerial release of sterile moths that USDA and FDA (Federal Drugs Administration) officials say will keep the Light Brown Apple Moth (LBAM) from reproducing, by rendering the eggs sterile [5]. The plan for 2009/2010 is to release 20 million male moths by air every 7-10 days that have been irradiated to stop sexual development and then doused with the pesticide pheromone CheckMate. A total of 100 million modified moths will be released in a bid to wipe out an estimated 25 000 LBAM.

Professor Joe Cummins of University of Western Ontario says this plan won’t work. “Irradiated male moths seldom work because the irradiated animals are weak and not perceived as very sexy by female moths,” he said. And, because the female LBAM moths are multiple maters, they live until they fertilize and lay eggs. He believes that the alternative to irradiated moths is worse still. This would involve the use of piggyBac transposons (see piggyBac a name to remember [6] to genetically modify terminator male moths that are considered sexy and mate very well, and produce dead offspring. The safety of terminator moths is of concern because piggyBac vectors are genetic units related to viruses that can move from one site to another in the same genome, or move between genomes belonging to unrelated species. PiggyBac vectors are active in mammals including humans making rampant horizontal gene transfer and recombination across species barriers possible (see Terminator insects give wings to genome invaders [7].)

Professor Cummins warns that other studies involving piggyBac such as the Oxford-Stanford business school dengue project and the cotton boll weevil releases have not been well demonstrated (see Terminator Mosquitoes to Control Dengue?[8].) “Millions of dollars have already been splurged on the Bay area LBAM programme to eradicate a tiny moth population,” he said.

Pesticide clouds

Professor Jim Carey, an entomologist from UC Davis says that the spraying programme to eradicate the LBAM has taken on a life of its own; just a handful of people made the decision to spray Californian cities surrounded by people who told them what to do, and the White House funded it to the tune of $75million. He says the State must re-think their plan and embrace a broader science of integrated pest management, and let the ecosystem balance out the LBAM because their plan will never, ever work.  He has compared it to similar spray regimes used in California against the medfly and the fruitfly that never worked either [9].

Nan Wishner, a key player in the campaign to stop the spray, and an advocate of integrated pest management systems praised the efforts of scientists and citizens so far.  She says that the State is operating on an obsolete war model to tackle the LBAM, a harmless pest; and the ground spraying will create pesticide clouds that are harmful to the health of urban populations.  “What the public wants is no pesticides”, she says.   It’s a generation gap that the bureaucrats have failed to understand because they want a situation where that can keep using these pesticides.

Pesticides are profitable

There is no doubt that the pesticides industry is big business. Over one billion tons of pesticides are used in the US every year [10]. Pesticides also generate large sums of money in advertising. According to the Berkeley Daily Planet, the USDA gave a $500 000 no bid contract to an advertising company to promote the now defunct CheckMate spray campaign.  Meanwhile, very little funding supports the clean up of the still contaminated orchards in California, a legacy of synthetic pesticides such as DDT used as far back as the 1940s [11].

Ongoing measures to combat the harmless LBAM are “kill stations” or pesticide traps containing the pheromone CheckMate put in trees and telephone polls along with SPLAT devices (Sound Lure Technology) to attract the moths to their doom. Some 3 000 SPLAT units per square mile will be placed on utility polls. Quarantines are still in place on retail nurseries that have to pay to spray their plants with Bt every two weeks at a cost of $50-1 000 000 per year which is putting nurseries out of business [9].

State unconcerned with environment

A.G. Kawamura, the state secretary of Food and Agriculture, defends the application to use irradiated moths which he says have been part of the State’s plan for more than a year.  He said that new science has prompted this change in direction not environmental concerns.  He said [1] “Our focus is to use technology that has moved progressively forward.”

Article first published 15/08/08


  1. Cummins J. Burcher S. Sex Hormones in City Life, Science in Society 39 (in press).
  2. Scherr J. Santa Cruz County wins stay on moth plan. The Berekely Daily Planet April 20 2008
  3. Cox C. Permethrin Insecticide Fact Sheet. Journal of Pesticide Reform 1998 volume 18 issue 2.
  4. Ho. MW. More illnesses linked to Bt crops. Science in Society 30 2008 9:10
  5. Burke G. Good News: Aerial pesticide spraying of urban areas suspended, Associated press 23 June 2008
  6. Cummins J.  PiggyBac a name to remember. ISIS report 15 March 2001,
  7. Ho. MW.  Terminator insects give wings to genome invaders. ISIS Report, 18 March 2001,
  8. Cummins J and Ho MW. Terminator mosquitoes to control dengue? Science in Society 39 (in press)
  9. What’s next for the Light Brown Apple Moth LBAM? Radio LBAM
  10. US Environmental Protection Agency Pesticides – The EPA and Food Security.”  EPA 2004
  11. Lynch A. Valley’s hidden pesticide risk, county leads state in contamination from old orchards. 10th October 2007

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