Issue link: http://read.dmtmag.com/i/56260
Pest Management • Brown lacewing numbers increased, for reasons unknown. Brown lacewings are also effective predators. • Asian ladybeetles declined in all tree fruit orchards sprayed with reduced-risk insecticides. • Native ladybeetle species, particularly two-spotted ladybirds, increased in all the orchards. This might represent a "regional recovery," Whalon said, "since their numbers declined after the Asian lady- beetle was introduced to counter the also- introduced soybean aphid. • Aphid parasitoids greatly declined in reduced-risk orchards. • Aphids, thrips, European red mites, and two-spotted spider mites noticeably increased in reduced-risk orchards. Of the 22 orchards in the study, eight used organophosphate insecticides, eight used reduced-risk insecticides, and six used organic methods. The organophos- phate orchards, where beneficial insects have gained resistance, were about equal to organic orchards in number and diversity of beneficials. The study used yellow sticky traps to monitor for nine pest insects and 26 genera of beneficial insects and double that number of species, calling them "ecological indicators." After the Food Quality Protection Act was passed in 1996, Whalon became involved in evaluating effects of new actions being taken by the EPA. The phaseout of azinphos-methyl was of par- ticular concern because both apple and tart cherry growers relied on it heavily for control of internal fruit-feeding insects. Tart cherry growers have yet to find ways, using reduced-risked insecticides, to achieve the total control of plum curculio and cherry fruit fly larvae required by the U.S. Food and Drug Administration. While Whalon believes that azinphos- methyl can be dangerous to humans and to aquatic organisms, he is convinced that eliminating the chemical will have nega- tive environmental effects as unintended consequences. His recent study showed, in effect, that orchards under the reduced-risk regimen are more sterile of beneficial insects and will require more sprays for insect control, not fewer. In a study of four orchards he did two years ago, he found that growers obtained "ecological returns" of $12.32 per tree when they used organophosphate insec- ticides compared with $6.89 using reduced-risk insecticides. Whalon has worked to quantify the value of "services rendered by beneficial organisms." Just how valuable is it to have a green lacewing eat 600 aphids? Putting an economic value on that has been difficult. If the apple industry had the functional ecology data that it now has when the EPA implemented the Food Quality Protection Act, it might have maintained azinphos- methyl's registration with limitations, he said. The Michigan Apple Committee has www.DelegateInsecticide.com 800-258-3033 ®Trademark of Dow AgroSciences LLC ©2010 Dow AgroSciences LLC. Always read and follow label directions. M38-359-001 (11/10) BR 010-42145 DAAGDELE0054 supported Whalon's work to have real data available in the event that the well- being of growers is threatened by EPA or congressional actions. These data will likely be even more critical for the Michigan apple industry as it lobbies for extension of the use of the organophosphate class of chemicals with government agencies as well as the public, Whalon said. • www.goodfruit.com GOOD FRUIT GROWER MARCH 1, 2012 23