Let the bedbugs bite

STEALING BLOOD  Three to 12 minutes is enough for Cimex lectularius to use its long piercing mouthparts (shown in a false-color image) for a stealthy blood heist.

Janice Haney Carr/CDC

Harold Harlan has been feeding bedbugs, intentionally, on his own blood since 1973. He keeps pint or quart jars in his home containing at least 4,000 bugs. And now Harlan’s self-sacrifice is helping other researchers studying the recent resurgence of bedbugs in the United States and other parts of the world.

For most of the first 25 years of this enterprise, Harlan (below) worked as a commissioned U.S. Army entomologist, and bedbugs were a pet project. Then the bugs made a comeback, and other researchers needed advice on care and feeding as they set up laboratory colonies. They also needed a bedbug source.

“I ask them to pay for shipping,” says Harlan, now working for the Armed Forces Pest Management Board. He has provided his blood for free, in the course of rearing 6,000-plus bedbugs (so far) for the starter kits he sends out. 

A fair number have been restarter kits and re-restarters, as other researchers struggled to get bedbug husbandry right. One team, attempting to avoid the need for human feeders, lost its bedbugs after inadvertently exposing them to an antiparasite drug in slaughterhouse blood from chickens.

“My bugs are wimpier than most,” Harlan says. Decades of protecting his colony from pesticides, plus inbreeding, have rendered Harlan’s bedbugs a point of comparison for today’s many pesticide-resistant forms. So far, authors of at least 45 scientific articles by researchers coast to coast have used his strain.

The Harlan strain started with bedbugs he collected at Fort Dix, N.J., where he had been called in to deal with a mysterious infestation. To study them, he would have to feed them. “I was so fascinated by them, that wasn’t an issue,” he says. As an entomology student, he had been expected to feed mosquitoes in the lab.

Harlan has learned to be as careful about protecting his bugs from people as vice versa. One jarful succumbed to the wafting mist of a cleaning aerosol that his wife, Norma, spritzed on a duster. When his children were young, he kept the containers hidden away, and when the family moved — as military families often do — he transferred the bedbugs himself. “It’s no more difficult than taking care of your china or glassware,” he says. Which is one way of looking at it.

Feeling the itch

On weekends a couple times per month, entomologist Harold Harlan feeds about half a dozen jars of bedbugs for roughly half an hour each. He rears the bugs in wide-mouthed jars topped with fine mesh, and to feed them he presses the mesh against the skin on his leg (jar shown above) and tries to distract himself with a book or TV.

Bedbugs can draw blood from most people without even waking them. Unfortunately, Harlan is one of the rare people who can feel the initial bites. After repeated exposure, the human immune system mounts an itching, swelling allergic reaction, Harlan says. About half an hour after a feeding session, the area around the bites reddens, and a day or so later a secondary, intensely itchy swelling reaction occurs.

Harlan has heard that, in theory, people repeatedly exposed to bedbug saliva could reach a point where bites no longer cause skin reactions. But for him, 40 years has not been long enough to eliminate the itch caused by his research bugs.“I just put up with it, because if I didn’t they wouldn’t stay alive,” Harlan says.

Harold Harlan feeds his bedbugs. H. Harlan

Susan Milius is the life sciences writer, covering organismal biology and evolution, and has a special passion for plants, fungi and invertebrates. She studied biology and English literature.

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