Bedbugs Beat Pesticides Their Own Way

Bedbugs have evolved an insecticide-resistance strategy unlike that of any other pest: They beef up levels of pesticide-detoxifying genes in a layer of cells just beneath their exoskeletons, according to a study (Sci. Rep., DOI: 10.1038/srep01456). That information might help chemists design more effective ways to control bedbug infestations. Subba R. Palli and colleagues collected bedbugs from dwellings in Cincinnati, Louisville, and Lexington, the home of their institution, the University of Kentucky. The researchers analyzed the pests’ RNA transcriptomes, along with those of bedbugs raised in the lab. They learned that bedbugs stave off pesticides such as deltamethrin in multiple ways, in particular by increasing levels of pesticide-detoxifying cytochrome P450 enzymes and transporter proteins that pump the chemicals out of cells. Many insects use those strategies, but they don’t concentrate their efforts near their exoskeleton the way bedbugs do. Because bedbugs feed on blood and not poisoned bait, insecticides targeting them are designed to kill on contact. It seems the pests may have adapted by strengthening the key cellular barrier under the exoskeleton as a first line of defense, the researchers say.