Twenty years ago, bed bugs were an obscure pest rarely encountered by residents of the US. Today, bed bugs have resurged, invading human civilization from 5 star hotels to cruise ships, office suites, hospitals, stretch limos, dorm rooms and even public libraries. A question perplexing entomologists is, “Why have bed bugs resurged? What are we doing differently today that perhaps leads to bedbug resurgence? Or have bed bugs changed?” The answers to these questions may be important for policy and management techniques for bed bugs.
Numerous factors have changed in pest control. Health concerns have led to a ban on the indoor use of cholinesterase inhibitors in 2002. Since then, indoor pest control has relied mostly on pyrethroid insecticides and a few other pesticides that have recently been brought to market. Control of cockroaches and ants has moved from baseboard sprays, (that may have had some secondary effect on bed bug populations) to use of baits that have no effect at all on bed bugs.
Entomologists are scrambling to fill the gaps in our knowledge. One line of research is evaluation of agents that are used to control bed bugs. This research has found that many populations of bed bugs are highly resistant to pyrethroid insecticides. Thus, some of the insecticides most commonly used indoors may no longer control bed bugs. A group of entomologists at the University of Kentucky have recently published evidence for high levels of bed bug resistance to common pyrethroid insecticides.
Insecticide resistance appears to be an important factor in bed bug resurgence, but it may not be the only one. Davies and colleagues at Rothamsted in the UK review possible factors in bed bug resurgence and summarize the supporting evidence. Their conclusion is that a silver bullet insecticide or other “cure all” for our bed bug problems is unlikely to emerge. Bed bug control will require new policies and public awareness to slow and control the current epidemic.