IGRs: Bedbugs and Insect Growth Regulators

Bedbug infestations are not only creepy, they are expensive to treat. One type of chemical used to kill bedbugs is the insect growth regulator or IGR called hydroprene.

What Is An IGR?

Insect growth regulators or IGRs do not kill insects. But they can help prevent insect larvae from maturing. Remember that only the adult phase of many insects such as bedbugs can breed. If a population stops breeding and no new breeding insects are introduced, eventually the insect population dies out.

IGRs can be used separately, but more often they are combined with pesticides. But you cannot find IGRs on the store shelf. These are regulated chemicals, which means that only a licensed exterminator can (or should) get a hold of them and use them.

Which IGR Is Which?

IGRs can be easily confused. The same company that manufactures Precor with methoprene, ZoÆ'†'" '''Æ'''«con, does make an IGR product for bedbugs called Gentrol. Its IGR ingredient is hydroprene, the only IGR affective against bedbugs, according to Virginia Tech entomologist Dini M. Miller, PhD. But unfortunately, some exterminators have been reported using methoprene in the belief that it worked like hydroprene. Also, some people may have done a quick Internet search and picked up information about IGRs and bedbugs from dubious sources.

For example, one major typo on the otherwise highly respected articles by University of Nebraska-Lincoln entomologist Barb Ogg, PhD accidentally states that the brand name Precor is recommended for bedbugs. Later on in the article, hydroprene is identified as the brand name Gentrol. However, anyone skimming the article and not taking the time to read the entire thing may mistakenly think Precor is the product they need. If they have bedbugs, then chances are high that they haven't had much sleep lately.

What Does Precor Kill?

Methoprene helps to stop severe flea infestations, not bedbug infestations. But it cannot be used alone to manage a flea infestation because it cannot infect adult fleas or fleas that are already breeding, only flea larvae and flea eggs. Since Precor is a combination of methoprene and two pyrethroid insecticides, it should be able to kill the adults, but not before they've bred.

Regular vacuuming, laundry and housecleaning can help to reduce both the populations of bedbugs and fleas, but housecleaning does not do the job all by itself. It needs to be combined with a chemical assault in order to eliminate these two blood-sucking pests.

How Effective Are IGRs against Bedbugs?

IGRs like hydroprene work much better under laboratory conditions than in real world conditions. As explained by Dini M. Miller, bedbugs are constantly exposed to hydroprene and therefore die in larger numbers. But how can you guarantee a constant exposure in the home environment? This can be a problem.

Miller also notes that some bedbug larvae exposed to hydroprene did survive to adulthood and mated once before they died. Although they died before their normal lifespan expired, they still were able to breed. So, do not expect miracles using hydroprene against bedbugs. It may take more than one application before the bedbugs are gone.



References

Zoecon Professional Products: Precor http://www.zoecon.com/precor.htm

Zoecon Professional Products: Gentrol http://www.zoecon.com/brochurerequest.htm

Virginia Department of Agriculture and Consumer Services: Bed Bug Treatment Using Insecticides; Dini M. Miller, PhD http://www.vdacs.virginia.gov/pesticides/pdffiles/bb-treatment1.pdf

Hawaii State Department of Health Vector Control Branch: Bed Bugs and Bed Bug Control http://hawaii.gov/health/environmental/vector/bedbugsflyer.pdf

University of Nebraska-Lincoln. "Managing Bed Bugs." Barb Ogg, PhD. http://lancaster.unl.edu/pest/resources/bedbug263.shtml