Given that logic wasn’t working, thank gawd politics did. Today the State of California and the Federal government announced that aerial spraying of urban areas to “eradicate” the light brown apple moth (LBAM) would not be conducted as planned. This is a victory for those activists who let their elected representatives know that they didn’t want to be sprayed with untested chemicals for a questionable purpose with failure the likely result. I thank all those who took a more active role than I did. Given my concerns with asthma and the fact that the sprayed particles were small enough to be breathed into lungs, it’s no wonder there were earlier reports of problems from people with asthma. I was not looking forward to having to deal with the spraying.

In addition, as an ecological urban gardener, I had a “down to earth” concern. I recently heard Daniel Harder, Ph.D., Executive Director of the University of California, Santa Cruz Arboretum, speak about the LBAM. (See my earlier post on his trip to New Zealand to investigate the moth.) He has checked LBAM traps and found that the pheremones used attract not only LBAM, but other insects as well. Thus, blanketing urban areas with pheremones to disrupt LBAM mating could have also disrupted life cycles of other insects. These effects are simply unknown at this point, but it is possible that the pheremones would have reduced populations of “good” insects I rely on to control pests in my own garden.

This, unfortunately, is the approach of industrial agriculture. Find a “problem” and “fix it.” Other consequences be damned. If other problems arise (and they always do in interconnected ecosystems), then fix those problems when they arise. I’m glad that in this case the over-reaction to LBAM has been stopped, and urban gardeners will not be subjected to ecosystem-disrupting pheremones.

One final point is important. Why did I just write “over-reaction” to LBAM? For two reasons. First, there is no evidence that LBAM actually is an agricultural pest in California. Court decisions in Santa Cruz and Monterey Counties halted spraying in those counties based on a simple piece of logic: the State failed to demonstrate that crops had been damaged by LBAM. Given that entomologists believe LBAM has probably been in California for decades and was only recently identified, if it were to become a pest it would have done so by now.

The second reason the State and Federal government over-reacted is quite simple. Dr. Harder mentioned that the LBAM’s natural habitat is in cooler regions, such as along the California coast. I was curious about his assertion and checked it out. Maps available from the State’s website on LBAM clearly show that the only places LBAM has been found is along the coast, where weather is cooler. In other words, it doesn’t appear to pose any risk at all for agriculture in the Central Valley, California’s agricultural workhorse.

This really got my curiousity up, so I looked even further. A quick internet search found an article on LBAM distribution: The Bionomics, Distribution and Host Range of the Light Brown Apple Moth, Epiphyas Postvittana (Walk.) (Tortricidae), by W. Danthanarayana, published in 1975 (Australian Journal of Zoology 23(3), 419 – 437 ). The following sentence from the abstract seemed critical [Farenheit temperatures added]:

No eggs hatched at > 31.3ºC [88ºF]; the upper threshold for larval and pupal development was 31-32ºC [89.6ºF].

It’s clear why LBAM hasn’t been found in the Central Valley and why it does not pose a risk there to agriculture. Temperatures in the Central Valley regularly exceed 90ºF in spring, summer and early fall.

So, given that LBAM has not yet become an agricultural pest in California, and isn’t likely to spread to California’s agricultural heartland, why are the State of California and the Federal government so concerned? My theory is that it’s marketing, pure and simple. Other countries (Australia, New Zealand, Great Britain, Europe) have the LBAM but it isn’t a major pest. Yet, in the U.S., it has been declared a Class A pest, meaning that extreme efforts will be made to keep it out of the U.S. Why? As long as it isn’t in the U.S., crops from the U.S. can be marketed abroad as “LBAM free.” This probably means exporters can get a slight price premium or a marketing edge for U.S. products over the same product from a non-LBAM-free country. As long as the U.S. government can convince people that the LBAM is a dangerous pest, and that U.S. agricultural exports are free of LBAM, industrial agriculture can market its products better.