New research is peering into the behavior of bed bugs and uncovers a natural element in our skin that can be used as a defense against them.

Bed bugs (Cimex lectularius) are repelled by certain lipids in our skin. The findings help illustrate why these pests don’t live on our skin for long periods of time like lice, for example. They might also point to new ways of keeping these insects away from us altogether.

Bed bugs B gone

“We already knew that human body odors, carbon dioxide, and warmth attract bed bugs to feed on people. Our latest research shows the reason they do not stay on humans like other pests, such as lice, is due to lipids or triglycerides in our skin that cause them to leave their hosts and hide in nearby locations, such as beds and mattresses,” said Zach DeVries, assistant professor of urban entomology with the UK College of Agriculture, Food and Environment.

For the study, the team obtained samples of the substances in question by asking participants to rub strips of filter paper on their skin. The sample included six volunteers between 25 and 50 years old, three males and three females, representing several ethnicities (white/Caucasian, Hispanic, Asian). Participants were asked not to eat “spicy” foods for at least 24 hours before the experiment, take a morning shower, not use deodorant or cosmetics before the experiment, and avoid strenuous physical activity.

Four populations of bed bugs were used in the study; one was reared in the lab, and the other three were collected in the wild (various apartments). All four groups strongly preferred control swabs, which were not used by any of the participants, over the ones that had made contact with the participants’ skin. An overwhelming 94% of the males in all groups chose the control papers over the experimental ones when presented with the choice.

“Our findings were consistent across all triglyceride types, all participant groups, and all bed bug populations,” DeVries said. “Bed bugs nearly always preferred the control filter strip to the one containing skin triglycerides.”

“The bed bugs do not like to sit on skin triglycerides and refuse to stay on surfaces that contain triglycerides,” adds Sudip Gaire, PhD and postdoctoral researcher at the University of Kentucky and lead author of the paper. “We got tremendous results by using only a small amount of triglycerides.”

For now, we don’t know for sure why these compounds repel the bedbugs; it seems a bit counterintuitive for a parasite that infests our skin to have such a distaste for the compound it contains. This raises the possibility that the substances identified in the study evolved specifically as bug repellents in our skin, although the current study cannot say for sure whether this is the case or not.

Still, given the sheer distaste bedbugs showed for these compounds, the authors are confident they can form the basis of new and more effective bed bug control options in the future.

“There may be several potential management opportunities from our finding,” DeVries said. “It’s possible [they] could be used to deter bed bugs from hitchhiking on people’s belongings, thus reducing their spread.”

The study “Human skin triglycerides prevent bed bug (Cimex lectularius L.) arrestment” has been published in the journal Scientific Reports.