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When state and federal agencies announced June 19 that they are going to release millions of sterile moths into California cities to combat the crop-threatening light brown apple moth (LBAM), they insisted that their alternative pheromone spray program was safe and would continue to be applied in rural areas.
"Aerial applications will continue to be an important tool, especially in densely forested areas," says the statement on the California Department of Food and Agriculture’s Web site. "Our health officials did not find a link between the spraying and reported illnesses."
CDFA’s strategic shift also fueled fears that the state is simply exchanging one ineffective tool for another in an effort to appear to be doing something to combat the moth.
"The first one, the public didn’t like," said University of California, Davis entomology professor James Carey. "The second is a complete waste of money. They can’t eradicate these things, but [it] lets CDFA throw more public money down the rat hole."
As the Guardian has reported (see "Godzilla versus Mothra," 01/02/08), Carey believes that the moth, which has been found in a dozen California counties, probably arrived decades ago, not several years ago as state officials maintain.
CDFA spokesperson Steve Lyle acknowledges that some scientists say the LBAM has been here for as long as 50 years, but he’s seen no proof of that assertion, noting that CDFA trapping data found no moths in 2005, but plenty in 2007. "We’ve asked them to provide data, but they’ve yet to release anything," Lyle told the Guardian.
Carey believes CDFA’s 2005 trapping program was inadequately concentrated: "There is no way that CDFA can make any statements on the absence of LBAM in the state based on their 2005 trapping program…. Thus the extent of spread still has to be reconciled with known rates of spread of insects. This is a long-term infestation that has been around for many decades."
Lyle admits that sterile insect technology is an unproven LBAM eradication method. "But we’ve used it successfully in the Central Valley to keep the pink bollworm moth, which is a pest of cotton, at bay, and we’ve successfully moved from malathion to sterile insect technology to treat the medfly," Lyle said.
State officials claim that they switched tools because a pilot study (cofunded by the US Department of Agriculture) in rearing a viable colony of moths at the Agricultural Research Services labs in Albany yielded promising results much earlier than anticipated.
"Because of this success," wrote CDFA Secretary A.G.<0x0007>Kawamura in a June 13 memo to Gov. Arnold Schwarzenegger’s Cabinet Secretary Dan Dunmoyer, "CDFA anticipates that we will be able to move up a delivery date for sterile moths to two years, a timeline that would allow us to utilize it in the central coast region program."
Noting that a single-engine Cessna flies over the Los Angeles Basin each day releasing millions of sterile medflies, Lyle predicts that the state’s sterile moth release program "will be no more distinctive than that," and that the irradiated moths will be "no more radioactive than people’s teeth after a dental X-ray."
"The moths receive a minute amount of radiation that stunts the growth of their reproductive organs," Lyle explained.
USDA’s Larry Hawkins told the Guardian that sterile males and females will be released. "The females won’t be able to lay fertile eggs, but they might be putting out pheromones that draw wild males," Hawkins says, noting that the USDA may need to allocate more money to the program in addition to the funding now in place: $15 million in 2007 and $74.5 million in 2008.
The consequences of California having LBAM already include being quarantined by Canada, Mexico and Chile, with China and South Korea considering similar moves, Hawkins says.
"LBAM typically attacks leaves, but that doesn’t mean it never attacks fruit," said Hawkins, who believes California is posing a risk by leaving the moths untreated this summer, and that the nation needs to build public awareness (see "Chemicals and quarantines," 03/05/08) about invasive pests given accelerating climate change and global travel.
"The insect has not stopped breeding, and our trapping data shows the insect continues to spread and its numbers to go up," Hawkins warned.
But Carey predicts that "the moth problem," in terms of damage to plants, will turn out to be "pretty much nothing on the ground."
"Trade is about dealing with risk, through an agreement between a buyer and seller, that if seller doesn’t find X number of moths because the buyer has been spraying, then the seller can ship the produce," Carey opined. "This is the future of pest control."