More bed bug research: Stephen Kells at the University of Minnesota

by nobugsonme on April 3, 2008 · 8 comments

in bed bug research, bed bugs, entomologists

Richard Shin reports for The Pioneer Press on research being done by Stephen Kells on bed bugs at the University of Minnesota.

Kells is at least one of the entomologists working on making an effective bed bug trap.

Alas, “we’re quite a distance off” from a monitoring trap, Kells said.

Eventually, it will be a wonderful invention.

It was interesting to hear how Kells got into bed bug research:

Kells first encountered a bedbug in about 2000 while working in the pest-control industry in Canada.

He dipped it into insecticide. The beast lived for four days and laid eggs.

“At that point, I knew we were in trouble,” he said.

Kells decided to study the insects further in an academic setting. He came to the University of Minnesota 3 1/2 years ago and set up a lab devoted to bedbug research.

About 2,000 bedbugs live there, housed in jars, where they crawl around pieces of filter paper that vibrate and twitch with their constant motion.

They eat Red Cross-donated human blood that’s beyond the expiration date, heated to body temperature.

Kells built a special platform he calls a bedbug arena, where he can observe the behavior of individuals when exposed to stimuli like heat. Part of his research is funded by the Propane Education Research Council, which wants to know whether propane-heaters can be used to kill the insects.

Another set of experiments involves attaching bedbug antennae to tiny electrical probes to see what kind of chemical compounds the antennae are tuned to receive. This might help develop the lure — maybe the carbon dioxide that sleeping humans exhale or the fatty acids on our skin — for a bedbug monitoring trap.

I am trying to envision the little tiny electrodes on the little tiny antennae. I also was fascinated by the bed bugs eating expired Red Cross blood, since all the other times we’ve read about researchers feeding their own bed bug colonies (as Lou Sorkin does) or having their grad students do it. I suppose it would be difficult to support 2,000 bed bugs.

The article also talks about the differences between captive bed bug colonies, and “wild” bed bugs, and it cites Harold Harlan, former Army entomologist (and author of the Armed Forces bed bug guide), as the source of Kells’ colony:

Bedbugs are a lot more resistant to poisons than they used to be. It takes 1,200 times the amount of insecticide to kill recently captured bedbugs than it takes to kill individuals from bedbug colonies that have been in captivity for more than 30 years, Kells said.

That captive colony was maintained by Harlan, who collected about 600 individuals from a barracks at Fort Dix, N.J., in the early 1970s. They were a novelty at the time, Harlan said. Over the years, he kept the colony alive in jars, letting it grow into the thousands, by allowing the bugs to feed on his legs.

“I’ve had them escape a few times in my house,” he said.

He had to leave the colony untended for a year when he was deployed in Vietnam and couldn’t find anyone willing to be a food source. When he came home, enough had survived to rebuild the population. Now his pets have become a resource for researchers.

I have a hunch this is where we got the information that bed bugs could survive, unfed, for a year. (We still aren’t sure where the “18 months” rule came from.)

Thanks to all the bed bug researchers, and universities, foundations and private companies that fund their work.

And thanks to the Pioneer Press for an informative article!

1 DougSummersMS April 4, 2008 at 1:02 am

I believe that the 18 month figure is based on Usinger’s research. He found that under ideal conditions a fifth instar nymph can live an average of 484 days after a feeding.

2 lieutenantdan April 4, 2008 at 8:51 am

In providing this kind of information to the public makes this some of the best if not the best reporting on the bed bug epidemic that I have seen. Very informative.

Adam from U.S. News & World Reports and the reporter from the Washington Post should read this.

I want to comment on the time that a bed bug can live without a blood feed. I would guess it comes down to a percentage game meaning that in certain conditions a bed bug can live to 15 or 18 months after a blood feed. I wonder if a bed bug’s life span can be shortened by stress such as just being missed by a steamer a few times.

3 nobugsonme April 4, 2008 at 9:36 am

Thanks Doug! I should have known it was Usinger.

4 Lou June 30, 2008 at 7:33 am

Actually the 18 month figure I don’t believe is what occurred under “ideal conditions”, rather the bug in question was kept under very cool conditions (around 54dF- ideal for waiting, not ideal for a quick life cycle). Don’t remember if this was a fifth instar nymph or an adult male that was able to live 484 days after a feeding. I’ll look up that reference in Usinger’s book and let you know. I may have posted this some time ago on the list. If deprived of food and kept warm or hot, bed bugs will die sooner than if kept under cool or cold conditions.

5 Lou June 30, 2008 at 12:01 pm

Table 2.2 (p.13 – Usinger, 1966 – taken from Omori, 1941)

Longevity (mean days) of once-fed Cimex lectularius (& C. hemipterus) at various temps and 70-75% RH

10ºC (50ºF) instar 5 remained alive 484.9 days while at 37ºC (98.6ºF) only lasted 32.6 days.
At same temps, adult female lasted 425 days and 31.9 days, respectively, while a male lasted 401.9 days and 28.6 days, respectively.
Instar 1 lasted 274.6 days and 16.8 days, respectively. Other nymphal stages and interim temps also listed – what I listed are the extremes.
Usinger noted that “the longevity of fasting adults of C. lectularius and C. hemipterus (after having once fed) is greatest at low temperatures and least at high temperatures.”
So items stored at warm temperatures will result in faster bed bug death than keeping same materials under cooler conditions.
I believe that reason to keep items stored 18 months to kill bed bugs is based on somewhat false (or misleading) information.

6 Doug Summers MS June 30, 2008 at 3:26 pm

Thanks for clarifying that the primary variable was temperature.

When I used the term “ideal conditions”… I meant the trial that produced the longest survival times.

Would lower humidity conditions also contribute to foreshortening a bed bugs expected life span?

Are there any other measures in addition to raising the ambient temperature that we could utilize to shorten the life span of bed bugs hidden in contents that are being stored?

7 Lou June 30, 2008 at 5:13 pm

I think that low humidity and high temp would be more detrimental to their existence. Probably the lower humidity has more of a deleterious effect on lightly sclerotized nymphs rather than on more sclerotized adults.
I’m trying to get the original paper by Omori.

8 Mel July 13, 2009 at 10:23 am

So there’s evidence that lifespan can be shorter in hot conditions. Trying to remember where I read reference to studies that reproduction is faster in warm conditions than cool ones, as long as there’s a food source.

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