New research on bedbug insecticide resistance

Since I mentioned bedbugs recently, I thought I would also cover this paper:

BPR3

Kyong Sup Yoon, Deok Ho Kwon, Joseph P. Strycharz, Craig S. Hollingsworth, Si Hyeock Lee, J. Marshall Clark (2008). Biochemical and Molecular Analysis of Deltamethrin Resistance in the Common Bed Bug (Hemiptera: Cimicidae) Journal of Medical Entomology, 45 (6), 1092-1101 DOI: 10.1603/0022-2585(2008)45[1092:BAMAOD]2.0.CO;2

One of the biggest issues in bed bug control right now is the development of resistance to insecticides. In fact, the New York City population of bedbugs used in this study was 264-fold more resistant to 1% deltapermethrin compared with a population collected in Florida!

To put it another way:  the Florida bed bugs were killed in 19 minutes; the New York bedbugs took 5,048 minutes, or over 3.5 days, to die.  Uh Oh.

The research  paper itself is a rather technical evaluation of just how and where, in terms of molecular biology, the mutation that makes the bed bugs resistant occurs.  Interestingly, it’s kdr resistance once again! (kdr stands for “Knock-Down Resistance.”)

I’ve mentioned kdr mutations several times here at the Bug Blog in discussions about DDT.  Basically, most insecticides act as a nerve poison for insects.  Insecticides block  ion flow (alternate animation) across a nerve membrane by attacking sodium channels. If the nerve can’t depolarize, the cell (and animal) is effectively paralyzed.

Kdr mutations are usually point mutations — a tiny change in one amino acid in a giant string of DNA.  It makes just enough of a change to make the bugs resistant.

Kdr mutations are also problematic because they often make a bug resistant to more than one insecticide. This means that an already difficult to control insect just got a lot harder to kill, since your tools (insecticides) wear out faster.

The conclusion of the paper:

“This evidence suggests that the two mutations are likely the major resistance-causing mutations in the deltamethrin-resistant NY-BB through a knockdown-type nerve insensitivity mechanism.”

AND:

“Because DDT has been used indiscriminately to control many insect pest species including bed bug, the widespread and frequent use of DDT is likely to have predisposed bed bug populations to pyrethroid resistance through the neuronal insensitivity mechanism.

So, what does this new information tell us?

  • DDT will be utterly useless against bed bugs, so people should stop asking for it.
  • We’re going to need a lot more research on ways to kill bedbugs other than just poisoning them with the usual pesticide suspects.
  • In cities where there are active bed bug populations, insecticide choice for resistance management will be very important in urban entomology.
  • Bedbugs are not going to go away, and you should probably be getting a little paranoid.

If, you know, you weren’t already paranoid when you read stuff like this.  What a nightmare.

14 thoughts on “New research on bedbug insecticide resistance

  1. It is amazing how the news media still clings to the idea that “Bed bugs came back because we banned DDT,” and as a non-entomologist, I fell for it too, at first.

    In fact the reality is much more complex, and bed bugs were showing signs of DDT resistance as early as the 40s.

  2. Back in the 1970s friends who’d been very careful about pesticides — their 2 year old was one of the very few in a big study who had no detectable pesticide body burden — moved into a rental house that had had a dog. Flea bites galore.

    I convinced a friend to lend us their cat, with a new fresh flea collar, and they took the cat to the house — empty, fairly cold — and left him there with an ample supply of food and water and a big litter box, for a week.

    Fleas jumped on cat as the only source of warmth in the house.

    It worked well enough.

    Not the nicest thing to do to the cat, but the cat survived fine and the baby no longer got flea bites when they went back into the house. They had the cat visit a few more times, I think, while leaving for weekend trips.

    I wonder now about the ‘Advantage’ and ‘Frontline’ topical flea and tick products used for cats and dogs and whether they’re effective on bedbugs.

    Slow is OK. “knockdown” fast kill is a marketing ploy. Question is do those things work at all. And if so can we use that kind of method.

    Yeah, paranoid, seems appropriate. What’s the biggest available source of unprotected meat on the planet these days, eh? What do we _expect_ nature to do about that?

  3. I heard it all hinged around cockroach spraying. While we used sprayed insecticides to control the cockroach populations the bedbugs couldn’t get established, but since the professionals moved to using hormonal treatments and targeted baits and traps instead, the bug population has made a resurgence. I was wondering if you knew anything about the effectiveness of diatomous (diatomatious?) earths and insecticidal dusts to control the bugs.

  4. Kate–Diatomaceous earth would be useless for bed bugs, and not a good idea in your bedroom anyway.
    You won’t be able to get it in the little cracks and crevices that bedbugs live in.
    Dusts will probably have the same problem.

    Why the bed bugs are back is a complex question–what you mention may have played a role, but increasing travel is also right up there. Harder economic times that increase re-use of discarded furniture and bedding is also not helping.

    http://membracid.wordpress.com/2008/09/18/how-to-inspect-your-hotel-room-for-bed-bugs/

  5. I like that idea of cooking them with hot air that’s mentioned in the article about Texas A&M. I’m somewhat surprised that 130 degrees is enough to do them in, but that seems like a practical process that wouldn’t leave survivors to reinfest the place.

  6. I think if I ever have an infestation I will use meticulous mechanical control for 18 months.
    After first decontaminating all the beds (or tossing them) I would put each one on a sheet of Plexiglas (or tinfoil for those so inclined lol) extending 2 or 3 feet further than the bed. The foot of each bed would go in a pail of soapy water (maybe diamataceous earth – one would have to experiment). Around the rim of the Plexiglas I would experiment with 2 to 3 inch bands of guck (maybe petroleum jelly mixed with household bleach). Perhaps I would do the same with a clean laundry station and with the desk that houses my computer.
    All the experts say ‘call in the professionals’. But here in Ottawa professionals charge $300/room. Even if I can afford that, many of my neighbours cannot. As long as Bedbugs live with my friends and neighbours, they live with me: buses, waiting rooms and the globetrotting youth than come to sleep over.
    My father said his mother used to have some mixture with which she treated cracks and beds. I looked into home remedies prior to 1914: paint the walls with kerosene, fumigate with hydrocyanic acid….
    …hmmm…. and here I was hoping one could simply sprinkle the house with lavender.
    Mind you, if I got tired of living that way for months, I could call in an expert in cold protecting the house (drain the pipes etc) and turn off the heat one mid January day when it is minus 20 centigrade. I would think the shelters in Toronto ought to do that once each winter. They could rotate days.

  7. Ed–For some reason, people seem very resistant to releasing insects in their bedroom…to catch other insects in their bedroom.

    Go Figure :)

  8. I’ve heard cockroaches are attracted to the smell the bugs give off and will eat what they can catch. It seems so hard to kill them where they live, can we kill them when they come to feed? We put flea collars on our pets so they absorb an insecticide to kill fleas that bite them. Maybe there’s something that will kill the bugs but we are immune to or tolerant of that we can ?coat our skins with, take as a capsule with dinner to kill bugs when we sleep? It might even work with lice. Several infestations dealt with at once.

  9. I was looking at the news today and they were talking about a bed bug epidemic. And of course I had a strange zip or so i thought on my face on Sunday and then today I saw a ziplike bump on my chest. These are singular spots and I know that bed bug bites come in clusters so i’m not sure if this is something else.

    The red spot on my check cleared up within a day and I’ll monitor the next spot. They don’t itch and they don’t hurt. I checked my bed for remnants and I don’t see anything.

    I’m having nighmares about these things now because I really don’t know what my two spots are.

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