In the Thick of It

Understanding why bed bugs have again become so common may help develop new strategies for their control, researchers say.

Resistance to commonly used insecticides is considered the main reason for the global resurgence in bed bugs, according to University of Sydney Ph.D. candidate David Lilly, whose research focuses on the biological mechanisms that help bed bugs survive exposure to commonly used insecticides. Being “thick” may be smart, for bed bugs at least, his research found.

“The new findings reveal that one way bed bugs beat insecticides is by developing a thicker ‘skin,’” said Lilly. “Bed bugs, like all insects, are covered by an exoskeleton called a cuticle. Using scanning electron microscopy, we were able to compare the thickness of cuticle taken from specimens of bed bugs resistant to insecticides and from those more easily killed by those same insecticides.”

Comparing the cuticle thickness of the bed bugs revealed a stunning difference: The thicker the cuticle, the more likely the bed bugs were to survive exposure to the insecticides. The new findings could explain why failures in the control of bed bug infestations are so common. They may also unlock new pathways to developing more effective insecticides for bed bug control.

“If we understand the biological mechanisms bed bugs use to beat insecticides, we may be able to spot a chink in their armor that we can exploit with new strategies,” Lilly said.

But measuring the thickness of bed bug cuticle wasn’t an easy task, he said: “The findings are exciting but collecting data was frustrating. Taking microscopic measurements of bed bug legs requires a steady hand and patience — lots of patience.”

Source: The University of Sydney media release, www.sydney.edu.au