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Bed Bugs Show Early Signs of Resistance to Chlorfenapyr and Bifenthrin


A new study of several field populations of the common bed bug (Cimex lectularius) finds that some populations show reduced susceptibility to two commonly used insecticides.

Pest management professionals battling the ongoing resurgence of bed bugs are wise to employ a well-rounded set of measures that reduces reliance on chemical control, as new research shows the early signs of resistance developing among bed bugs to two commonly used insecticides.

In a study published this week in the Journal of Economic Entomology, researchers at Purdue University found significantly reduced susceptibility to chlorfenapyr among three out of 10 bed bug populations collected in the field, and they found reduced susceptibility to bifenthrin among five of the populations.

The common bed bug (Cimex lectularius) already shows significant resistance to deltamethrin and some other pyrethroid-class insecticides, which is viewed as a main cause of its resurgence as an urban pest. In fact, 68 percent of pest management professionals identify bed bugs as the most difficult pest to control, according to a 2015 Bugs Without Borders survey of pest management professionals conducted by the National Pest Management Association and the University of Kentucky. Little research had yet been done, however, to examine potential resistance to bifenthrin (also a pyrethroid) or chlorfenapyr, a pyrrole-class insecticide, which led the Purdue researchers to investigate.

“In the past, bed bugs have repeatedly shown the ability to develop resistance to products overly relied upon for their control. The findings of the current study also show similar trends in regard to chlorfenapyr and bifenthrin resistance development in bed bugs,” says Ameya D. Gondhalekar, Ph.D., research assistant professor at Purdue’s Center for Urban and Industrial Pest Management. “With these findings in mind and from an insecticide resistance management perspective, both bifenthrin and chlorfenapyr should be integrated with other methods used for bed bug elimination in order to preserve their efficacy in the long term.”

They tested 10 populations of bed bugs that were collected and contributed by pest management professionals and university researchers in Indiana, New Jersey, Ohio, Tennessee, Virginia, and Washington, DC, measuring the percent of bed bugs killed within seven days of exposure to the insecticides. Generally, populations in which more than 25 percent of the beg bugs survived were deemed to have reduced susceptibility to the insecticide based on statistical analysis performed in comparison to the susceptible laboratory population.

Interestingly, the researchers found a correlation between chlorfenapyr and bifenthrin susceptibility among the bed bug populations, which was unexpected because the two insecticides work in different ways. Gondhalekar says further research is needed to understand why the bed bugs that are less susceptible can withstand exposure to these insecticides, especially chlorfenapyr. In any case, adherence to integrated pest management practices will slow the further development of resistance.

“There is a plethora of research that has shown that if insecticides are integrated with additional control measures such as vacuuming, steam or heat, mattress encasements, traps, and desiccant dusts, effective bed bug control can be accomplished  and theoretically this should reduce the risk of resistance build-up in populations,” Gondhalekar says.


  1. Thanks for your article, but this is old news to the pest control industry, and many have moved on from these two products.

  2. “Theoretically” …………..I REALLY hold theoretical applications is low esteem when:
    Pests like these or any pests at all are ALWAYS going to become resistant to insecticides, and result in more toxic applications.
    More than theoretically, Super Heat Treatments are the only true way to rid a home or an apartment building, motels, hotels, etc.
    I have researched this extensively and noxious insecticides are never going to be a permanent solution.
    Why just “manage” these horrid creatures, while poisoning the people’s dwelling places with neurotoxins and other sickening chemicals which can be related to Parkinson’s, Alzheimer’s, seizures, Asthma, Cardio/Pulmonary inflammation, nausea, gastrointestinal upset.

    • Done properly heat is effective at all stages, but heat has no residual impact. The potential for re-infestation is right back to where it was at the beginning. While it’s true resistance is an ongoing issue with pesticides and pests – that’s not why we’ve had this plague thrust upon America again. It was the elimination of effective, inexpensive pesticides by the EPA and the Food Quality Protection Act. After all these years there’s no evidence there’s any resistance to carbamates or organophosphates, and as for all the alleged diseases caused by pesticides – that’s all speculatory. Those claims are always preceded by weasel words and phrases such as “suspected, linked, might cause, studies suggest, could cause, the long term effects are unknown, voiced concerns about, expressed some concern,experts fear”.

      You might wish to see more Weasel Words and Phrases here…..

      The fact of the matter is in 1945 when the boys came back from WWII bed bugs were ubiquitous. But they came back with DDT and by 1946 a society – for the first time in human history – was able to eliminate them. The answer in 1946 was effective, inexpensive, readily available, easy to use chemistry – pesticides – and if that’s not the answer now there will be no answer.

      Rich Kozlovich, Exterminator

  3. The best solution to the bed bug problem is Heat Remediation!
    This is the most technologically advanced way of eradicating bed bugs IN 1 DAY! This custom state of the art manufactured system, includes RX12 Heaters, Air Movers, wireless temperature controls and monitors that have been specifically designed to eliminate your bed bug infestation. Once the system is in place, we increase and maintain a surface temperature of 130° to 148° (Fahrenheit) killing the bugs, nymphs & larvae within minutes. Bed bugs are ectoparasites with an outer skeleton that will quickly dry out and fracture in high heat.

  4. Is there a one chemical or one application that includes all three scientific formulas or Solutions to deter bed bugs without heat

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