Insects turn on several genes to stave off effects of insecticides

By Tina Hesman Saey

Web edition: March 14, 2013

Enlarge

Tough Bugs

Bedbugs (adults, nymphs and eggs shown) have developed multiple layers of resistance to pesticides, making it hard to control their populations.

Credit: Michael F. Potter

To escape the sting of insecticides, bedbugs boost activity of certain genes in their shells, a new study shows. Bedbugs are notorious for escaping unharmed by pesticides; understanding how the insects escape death could lead to better ways to fight the pests.

Researchers led by Subba Palli of the University of Kentucky in Lexington collected 21 groups of common bedbugs, Cimex lectularius, from four Midwestern cities. The researchers examined the activity of genes that slough off the effects of pyrethroid pesticides, a category of insecticide in some of the most common household bug sprays.

Bedbugs turn on diverse genes in their outer covering, called the cuticle or integument, the team reports March 13 in Scientific Reports. Those genes detoxify pesticides, stop them from penetrating and pump out the insecticides before they can reach the insects’ nerve cells, the researchers found. An additional pesticide resistance gene called kdr is active in the nerve cells, giving bedbugs multiple layers of protection. The scientists know of no other insects that use such a multipronged defense.