Studies on Bed Bugs
Pesticide Resistance
Recent studies show that bedbugs around the world have developed a resistance to the chemicals used to control them. Scientists are now studying the molecular biology of these pests to develop more lasting control measures. The new findings from entomologists at Ohio State University show that bedbugs may have boosted their natural defenses by generating higher levels of enzymes that can cleanse them of poisons.
In New York City, bedbugs now are 250 times more resistant to the standard pesticide than bedbugs in Florida, due to changes in a gene controlling the resilience of the nerve cells targeted by the insecticide, researchers at the University of Massachusetts in Amherst recently reported.
"These bugs have several back doors open to escape," said evolutionary entomologist Klaus Reinhardt at the University of Tuebingen in Germany, who was familiar with the new research but wasn't involved in the projects. "Simple spraying around of some pesticides may not [be enough] now or in the future.
New findings from entomologists at Ohio State University, show that bedbugs may have boosted their natural defenses by generating higher levels of enzymes that can cleanse themselves of common pyrethroid-based pesticides.
The findings add to a growing body of evidence from molecular-biology studies that bedbugs have recently evolved at least three improved biochemical defenses against common pesticides. Bedbugs today appear to have nerve cells better able to withstand the chemical effects, higher levels of enzymes that detoxify the lethal substances, and thicker shells that can block insecticides.
Laboratory tests in the U.S., Europe and Africa show today's bedbugs can survive pesticide levels a thousand times greater than the lethal dose of a decade or so ago. "There is a phenomenal level of resistance," said bedbug entomologist Michael Siva-Jothy at the University of Sheffield in the U.K. "It has evolved very recently."
Well-adapted to homes, hotels and dormitories, these tiny blood-sucking parasites usually hide in mattresses, bed frames and furniture upholstery. Bedbugs feed every five to 10 days, leaving painful welts on the skin and sometimes triggering allergic reactions.