Reprinted from the AEHA Spring 2014 Newsletter
Bed bugs have been a popular topic in the environmental health world lately. In the last several years, the United States has seen a steady increase in these small insects and, unfortunately, Alaska has not been an exception. While bed bugs don’t cause disease, they are gross and can take a serious financial and emotional toll. More importantly, concerns about the misuse of toxic pesticides have many agencies scrambling to issue informational guidelines to an anxious public.
If there is a silver lining to the upsurge in bed bug infestations, it may be the renewed interest in bed bug research. We know more about bed bugs than ever before, and new papers are being published regularly. I’d like to take a moment to summarize two recent research papers published in the Journal of Economic Entomology (I guess “Economic Entomology” is a thing.) I feel these articles may be of practical interest to our readership as they shed some light on two frequently asked questions.
Does Insect Repellent Work?
The short answer is, “Probably.” Wang et al. tested several repellents and found reasonably good results for several, including DEET. In their lab, a 25% concentration of DEET strongly repelled bed bugs from a fabric surface for 14 days. While DEET would not be an appropriate tool for eradicating bed bugs from a dwelling, it could be a useful tool for prevention. The findings suggest that spraying bags or backpacks before staying in bed bug-infested lodgings might offer protection against “hitchhikers.” Additionally, for those of us doing bed bug investigations, spraying a little “Alaskan Cologne” on our clothing before entering an infested dwelling could serve as an added layer of protection. Other compounds were tested, and found effective, but based on the ubiquity and low cost of DEET throughout our state, this seems like the most practical repellent option. This is a new area for research, so I wouldn’t count on DEET as a bulletproof deterrent, but I will certainly be adding it to my bed bug toolbox.
Does Freezing Kill Bed Bugs?
Yep. Due to the cold climate and remote nature of much of our state, freezing has been an attractive option for bed bug control. Unfortunately, the literature varies widely on the simple questions of “how cold?” and “how long?” A recent paper published by Olson et al. offered new insights and recommendations. They evaluated and modeled bed bug mortality following cold treatments. Significantly, they also tested commercial freezers to evaluate the real-world effectiveness of freezing bed bugs. What they found is that in a laboratory controlled setting, they could predict 100% bed bug mortality at -15°C after 85 hours. Temperatures colder than this required less time. Additionally, because of the wide temperature swings found in consumer freezers, 100% mortality was achieved in less time than expected (approximately 1 day). In summary, this research suggests that freezing is a viable option for bed bug extermination in our state. Reasonable advice would be to maintain temperatures of at least -15°C for several days.
J Econ Entomol. 2013 Dec;106(6):2522-9. Repellency of selected chemicals against the bed bug (Hemiptera: Cimicidae). Wang C1, Lü L2, Zhang A3, Liu C4.
J Econ Entomol. 2013 Dec;106(6):2433-41. Cold tolerance of bed bugs and practical recommendations for control. Olson JF1, Eaton M2, Kells SA2, Morin V3, Wang C4.
Contributed by Leif Albertson, UAF Cooperative Extension Service
Piotr Naskrecki. (2006). CDC Public Health Image Library.