[Technically Speaking] Bed bugs - the state of the union

It may appear that I and others have beat this horse to death — but the fact remains that bed bugs have become the most significant pest in commercial (apartments and hotels) accounts and are the most difficult pest to eradicate. The reasons for this are many but some of the most important are:
• Lack of current knowledge regarding biology and habits.
• The bed bugs’ tendency to seek harborage in sensitive environments, e.g., bed rooms, bedding, cribs, furniture, etc.
• Lack of knowledge regarding registered product efficacy, resistance and residual effects.
• Loss of previously more effective products such as chlorinated hydrocarbons, organophosphates and carbamates, which were more volatile and had different modes of action than today’s most widely used products, pyrethroids.
In my opinion, bed bugs have garnered the interest of the entomological community more rapidly than any other pest in recent history including fire ants and the Formosan termite. The reasons being their geographic distribution spans the union and they affect hundreds of thousands of people. The importance of the resurgence of this pest is underscored by the most recent Entomological Society of America conference that included a symposium dedicated to bed bugs and most recently published a series of articles in the summer 2006 issue of American Entomologist (Volume 52/Number 2/pp. 98-122). This month’s column, “The State of the Union,” summarizes some of the more important aspects of this series of articles, but I would highly recommend that you obtain a copy of the publication by writing the Managing Editor, Suite 100, 10001 Derekwood Lane, Lanham, MD 20706-4876.

harold harlan provided an overview of bed bug biology, habits and behavior.  Some of the most important facts to keep in mind are that:
• They can develop from egg (to adult) to egg in five weeks at 75 percent to 80 percent relative humidity and 28°C to 32°C — not uncommon conditions in heavily infested apartments.
• An adult female can live up to two years, producing 200 to 500 eggs.
• The bed bug’s life cycle is very analogous to the German cockroach and the ability for large populations to occur in a short period of time is obvious. 
• They are neither easy to kill with heat (requires greater than 45°C) nor cold (they remain active at as low as 7°C).
michael potter shared his experiences as an extension entomologist at the University of Kentucky and the prospects for the future indicating that:
• The current products are not as effective as those in the past.
• Bed bugs have garnered more media attention than West Nile virus and this does not bode well for our industry, which  is still groping for better solutions to this problem.
• Consumer intolerance for being bitten by bed bugs and hence becoming a blood meal, particularly in their sleeping quarters, portends lawsuits.
• There are no effective tools for detecting bed bugs and eradication is difficult because of their secretive habits and widespread dispersal in human habitations.
• With ten-fold increases in bed bug treatments during the past several years, the incidence of bed bugs will get worse before it gets better.

j. gangloff-kaufman, et al. conducted a survey of pest management companies throughout the United States.  The findings are somewhat enlightening:
• The Northeast region had the highest percent of companies providing bed bug services, followed in descending order by the Southeast and North Central regions (tied), the Pacific region, and the South Central region.
• Inspection of a bedroom took less technician time than treatment. The most common places to find bed bugs were on the mattress (98.2 percent), carpet and baseboard (94.1 percent), and box springs (93.6 percent).
• Most companies (62.6 percent) reported controlling bed bugs with two to three treatments; 10.7 percent indicated they needed five to six treatments; and 6.1 percent said they could do it in one (this I have to see).
• Most companies were using crack and crevice sprays as well as treating bedding.  Most reported having success using pyrethroids and most were using deltamethrin or cyfluthrin. IGRs, if used, were used in conjunction with residual sprays.
• Most companies reported that they were not using non-chemical means to eradicate bed bugs.

stephen kells provided an overview of non-chemical methods (inspections, vacuuming, steaming, isolation of infestibles, heat treatment, and use of mattress covers) used for bed bug management. Kells concluded that non-chemical control is an important component of any bed bug pest management program; however, if any of these techniques are used alone they do not provide adequate control of infestations.
richard cooper underscored the need for continued research and public awareness. On the first issue, most of the research we rely on is more than 40 years old and deals with products long lost to the industry. While the number of lab studies on bed bugs has increased significantly over the past several years there is a significant lack of applied (field) research. It’s great to know what products work in the field but the bigger question is how do they perform in the field?
There is more going on with bed bugs than we fully appreciate — the explosion of bed bug cases in my estimation is only surpassed by the proliferation of rat populations and plague of the Middle Ages — the good news is bed bugs don’t kill you. A segment of the population is well aware of the problem thanks to NPMA and the media that, for the most part, have done a good job maintaining a balanced approach to the situation. But there are many people living in situations where they will never hear about this widespread situation and, to avoid drawing attention to themselves, never report the problem.

robin todd reported on lab studies using 14 different products including residual sprays and dusts, contact sprays and dusts, and physical confinement. The substrates tested for residual activity were plywood and mattress covering. It’s great to know what products work in the lab:
• Residual products: All pyrethroids (deltamethrin, cyfluthrin, lambda cyhalothrin, permethrin, and drione) provided greater than 60 percent mortality on both substrates after aging for 27 days. Hydroprene did not prevent molting to the adult stage; it did not prevent viable egg production; however, adult mortality was between 66 percent and 100 percent.
• Direct contact products: The pyrethroid and pyrethrin products (pyrethrin and d-phenothrin) exhibited very little flushing activity. The pyrethrin-based products provided 95 percent to 100 percent knockdown, whereas the d-phenothrin-based product only provided 60 percent knockdown. All of these products provided 100 percent mortality at 24 hours. The limestone-based product only provided 20 percent mortality after five days exposure.
• The mattress protector prevented unfed bed bugs from feeding.

conclusion. As for the Bed Bug State of the Union, we will continue to see an increase in bed bug infestations despite our best efforts to educate the public. We have products that kill bed bugs. However, we need to apply a lot more product, more frequently, and to places we feel uneasy about. To better address bed bug problems we need more applied research sooner than later.

Richard Kramer can be reached at rkramer@giemedia.com.