An Interview with Dr. Susan Jones on Her 2015 Article from the Journal of Medical Entomology

The release of Dr. Susan Jones’ newest article, entitled “Sublethal Effects of ActiveGuard Exposure on Feeding Behavior and Fecundity of the Bed Bug (Hemiptera: Cimicidae)” sheds new and exciting light on the underlying mechanism(s) at the heart of ActiveGuard® Mattress Liner’s ability to prevent and control bed bugs for two years in the field.  However, this article is quite complex and may be just a bit more than the average person can digest.  That’s why we’ve invited Dr. Susan Jones to discuss some of the more important points of her paper.

Can you explain for us the difference between ‘sublethal effect’ and ‘sublethal dose’?

“It is very imperative to clearly distinguish the terms ‘sublethal effect’ and ‘sublethal dose.’  These two terms should never be used interchangeably. To do so is to foster misunderstanding of scientific concepts.  Sublethal is an adjective that means “short of death” or “less than lethal.”  A sublethal effect is manifest as a change in behavior, reproduction, development, growth, etc.  On the other hand, a sublethal dose is one that is less than lethal; it is not large enough to cause death. These are distinct terms with different implications.”

Dr. Jones…did you test various doses of permethrin or simply the standard fixed dose found in ActiveGuard®?

“Our 2015 Journal of Medical Entomology (JME) paper does not test sublethal doses of permethrin, but rather it reports on sublethal effects of the ActiveGuard® Mattress Liner. We tested the ActiveGuard® Mattress Liner at a fixed concentration of 550 mg permethrin per m2--this is how the product is marketed.  If we had intended to study sublethal doses of permethrin, we would have tested fabric that was impregnated with a wide range of permethrin concentrations, but we did not do so.”

What exposure time(s) were required to demonstrate sublethal effects in resistant bed bugs?  Does ActiveGuard® use as directed lead to increased resistance in bed bugs? 

“In our 2015 JME manuscript, we report on brief exposure times of 1 minute and 10 minutes because the permethrin-impregnated ActiveGuard® fabric very quickly kills susceptible bed bugs.  It takes longer to kill resistant bugs. This variable time to death is not unique to ActiveGuard® fabric, but rather, it is something that we have observed with many currently marketed bed bug products.  But a very important distinction is that the ActiveGuard® Mattress Liner is not to be used as a front-line tool, which is one that is used against heavy bed bug infestations. ActiveGuard® Mattress Liners are intended for use as a preventive tool or as the final treatment step within an integrated pest management (IPM) program. As such, the product should not place a chemical burden on a large bed bug population. Furthermore, in our JME paper, we provide data demonstrating decreased feeding and fecundity (egg production) of pyrethroid resistant and susceptible bed bugs after just 10 minutes of exposure to ActiveGuard® fabric as compared to untreated fabric.”

April 1, 2015

Dr. Susan C. Jones
Professor
Entomology Department
The Ohio State University

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