University of Delaware Office of Public Relations The Messenger Vol. 5, No. 3/1996 Research shows beneficial insects, environment suffer from electric traps Who would have thought the black lights of the '60s would come back in the '90s, designed to beckon not flower children but insects? Electric insect traps, complete with black lights and electric grids, have been marketed to consumers who want to keep their summer evenings free of biting flies, notably mosquitoes. The sound of a bug "frying" when hitting the electric trap may be a satisfying one to a consumer, but it sets Doug Tallamy's nerves on edge. The UD entomologist says the problem is not just a false sense of security for consumers-the electric traps do little to reduce the biting-fly population, he says- but the impact that the traps have on beneficial insects. Tallamy says it's not news to entomologists that most species of mosquitoes don't respond to black lights and that certain mosquitoes only bite during the day, anyway. So, what is getting fried in those traps? Tallamy enlisted the aid of Newark High School student Tim Frick to find out. Over the summer of 1994, the two collected and identified the kill from electric traps at six sites in suburban Newark, Del. The results, Tallamy says, disturbed his environmental sensibilities and should disturb those of others, as well. Only 31 of the nearly 14,000 electrocuted insects were biting flies. That's less than a quarter of one percent. Species from more than 104 nontarget insect families were destroyed. Almost half of these were aquatic insects-caddisflies and midges. To the untrained eye, midges look like mosquitoes. But, to a trained entomologist and a balanced ecosystem, there is a big difference. "Midges don't feed on mammalian blood or spread disease," Tallamy says, "and, they are an important part of the aquatic food chain as larvae. Diminishing their population has an effect on other populations, including the frogs and fish that feed on them. As adults, the midges also are an important food item for nesting birds. "The manufacturers claim their products kill insects and they do. Many of the electrocuted insects look like mosquitoes-an undesirable insect-but they are not mosquitoes," Tallamy says. "The heavy toll on nontarget insects and the near absence of biting flies in catches suggests that electric insect traps are worthless for biting-fly reduction," Tallamy says, "and probably are counterproductive to consumers and the larger ecosystem." -Claire McCabe, Delaware '85M