The roles of the other resistance genes identified by the Kentucky team remain to be fully explained, although the researchers found that most of them code for proteins that participate in metabolism, comprise the exoskeleton or transport chemicals into cell interiors. The researchers suspect the bed bug proteins slow pesticide penetration via the cuticle and detoxify chemicals before they can reach nerve cells, for example. But the very existence of multiple resistance mechanisms means that hitting the pests with our current chemical arsenal is potentially "a waste of time, money and has unnecessary possible toxic side effects," Vaidyanathan says. New ideas are needed; the most recent kind of pesticides approved for bed bugs, neonicotindoids, were first introduced to market in the early 1990s.
Improved understanding of how bed bugs tolerate insecticides could help researchers design toxins that aim at those defenses. The next generation of bed bug sprays may be a cocktail of chemicals that includes inhibitors to cripple the insect's detox mechanisms. "Work is already underway to look for inhibitors," Palli says.