If you’ve ever lived with bedbugs, you know there is something horribly disturbing about waking up in the middle of the night wondering if that itch is from a track of feeding marks caused by their needle-like mouths. Since the turn of this century, there has been a dramatic resurgence in the number of bedbugs lying in wait for people to sleep. In the U.S. alone, the number of emergency room visits for bed bug bites jumped from about 2000 in 2007, to almost 16,000 in 2010.

Consequently, measures are urgently needed to determine whether bedbugs are present in a dwelling, in order to implement control measures. Yet these small creatures are notoriously difficult to find, and current methods for detecting bed bugs are somewhat clunky and expensive.

The good news is that researchers from Simon Fraser University in Canada recently reported the recipe for the signal that bedbugs use to find one another.

This should make it much easier to rouse the little critters from their hiding places and determine whether they are causing an infestation, and it might also be useful for exterminating them.

The first step in conducting these experiments was to grow a colony of bed bugs. This was a challenging prospect, as bed bugs only feed on blood. One of the scientists in the study, a member of a husband and wife research team, volunteered her arms for nearly 200,000 bites to keep the colony healthy and growing. (Her husband apparently wasn’t a suitable donor, as he developed a severe itch when bitten.)  As a consequence of all this feeding, the bed bugs produced a large volume of shed skin and feces, which was the raw material for isolating the aggregation signal.

The scientists used chemicals to extract the key components that caused bed bugs to aggregate from 18,000 of their shed skins. It took about 18 months to collect the number of skins needed for their experiments.

They also allowed 300 bed bugs to poop on pieces of paper for a month, and then analyzed the fecal material contained on the paper with a machine called a gas chromatograph/mass spectrophotometer to detect the various individual components excreted by the bed bugs.

To test whether they found the correct compound, the researchers put bed bugs in a central round glass container, connected by small tubular passageways to two other containers with either a control scent or a test scent they had extracted from bed bug skin and feces. They then allowed the bed bugs to roam the chambers overnight, and determined where they ended up the next morning. If the bed bugs were attracted to the test scent over the control scent, the researchers knew they were on to something. By testing a variety of compounds isolated from the bed bug skins and feces, the researchers ultimately determined that a cocktail of histamine plus five other volatile chemicals was sufficient to attract and keep bed bugs in place. As the final test, the scientists went into infested apartments in Vancouver, British Columbia, and determined that their scent mixtures did effectively attract bed bugs “in the wild.”

This research will hopefully lead to more effective ways of detecting and eliminating bed bugs from a dwelling, and thereby eliminate the rashes and sleepless nights experienced by people who share their homes with these nasty little creatures.

More information is available in the article by Regine Gries and others entitled “Bed Bug Aggregation Pheromone Finally Identified” in Angewandte Chemie 54:  1135-1138, January, 2015.

Patrick Guilfoile has a doctorate in bacteriology and is the associate vice president at Bemidji State University.