[Technically Speaking] Bed bugs - no silver bullets

Are you still looking for a silver bullet to solve the escalating bed bug problem? Although we are learning more about this rebounding problem, at this point in time there are no simple answers for eradicating infestations.
The initial problem we encountered with bed bugs was finding an effective product for treatment. Six years ago few manufacturers listed bed bugs on their product labels — why should they, no one encountered these blood- thirsty suckers for almost 30  years.  I seriously doubt that any manufacturer listing them on the label at that time had done much, if any, efficacy testing and were relying on extrapolated data from other insect pests to include them on a product label. Who had colonies for testing purposes? Furthermore, who has them today?

NEW FINDINGS. When the bed bug problem was getting out of hand my original concern was that pyrethroids — the bulk of active ingredients currently available to the industry — would repel the bed bugs and drive them to adjoining units. Thus, my original recommendations were to use one of the few organophosphates, propetamphos, or the only carbamate, propoxur, available to the industry. Subsequent research by David Moore, a master’s degree student with Dr. Dini Miller at Virginia Polytechnic Institute and State University, found that most of the pyrethroids in common use are not repellent and thus may be equally as effective as non-pyrethroids. His research also has demonstrated that products vary significantly in the amount of time it takes to kill exposed bed bugs and that some field populations we are trying to eradicate are much hardier than lab colonies. Watch closely for their published research.
It is important to note that during the early years of bed bug control with modern pesticides (1950s and 1960s) resistance to chlorinated hydrocarbons and cyclodiene insecticides was an issue. Resistance studies were routinely performed on bed bug colonies maintained by USDA. Although bed bugs seemed to disappear for 30+ years they were never eradicated and the resistance mechanisms that evolved as the result of exposure to these earlier pesticides may result in cross resistance to products available today. To the best of my knowledge, the effect of an insect growth regulator (IGR) on bed bugs has not been studied in the lab.  Although David Moore has studied the use of an IGR in combination with residual pesticides, the results of that study are yet to be published.  Intuitively, one could assume that it will slow reproduction if not prevent it. Considering the fact that bed bugs have a reproductive potential comparable to the German cockroach, an IGR that slows or blocks reproduction is an added value. 

QUESTIONS TO BE ANSWERED. There is no doubt that liquid formulations currently available will kill bed bugs, but how effective and timely they are in eradicating infestations depends on many factors. There are numerous testimonials claiming efficacy of various dust formulations; however, in the absence of independent published research I question these claims. In most cases the unknown factor is how does the dust affect an insect that does not groom itself?  Inhale it?  Desiccate it?  These are questions yet to be answered.
I’m frequently asked about non-chemical means for eradicating bed bugs and there are some available that under ideal conditions and with minimal infestations can eradicate bed bugs. However, most of the property managers I have encountered are unwilling to pay the price for this type of service and perhaps the most discomforting part of this treatment is this — there is no residual to help prevent reinfestation.
Bed bug behavior is also very fascinating — there seems to be neither rhyme nor reason for where they can be found in heavy infestations.  For instance, recently in an immaculate apartment no evidence of activity was found any where except the 300+ bugs on the pillow top mattress. In contrast, in heavily infested apartments it is not uncommon to find all stages of bugs and eggs sporadically clustered along the ceiling-wall junction, in the uppermost corners of the bed rooms, and in the closets, and find very few on the bedding.  This seems to be odd behavior for an insect that prefers to feed at night, remain close to its host, and spend most of its time in tight cracks and crevices.
I have heard a few speakers on the circuit say that bed bugs do not travel far to find a host. A recent experience dispelled that theory. Eviction of a tenant from a garden style apartment revealed an infestation of several thousand bed bugs.  Within a week of the eviction, the tenant (no previous history of bed bugs) in the apartment immediately above the infested unit began collecting almost 100 bugs per night.  Two weeks later a new tenant (no previous history of bed bugs) diagonally above the evicted unit received 20 to 30 bites the first night of occupancy.  An inspection of the unit the next day revealed almost 50 live bugs on the walls throughout the unit. It makes me wonder how many weren’t seen; if it’s anything like cockroaches it could have been 500.
The types of situations in which bed bugs are found dictate how the infestation can be eradicated. In the case of private residences and high-end accounts that are willing to pay anything to eradicate the infestation and prevent further problems the options are virtually limitless. However, in apartments where there is a lot of finger-pointing as to where they came from and budgetary constraints on the apartment manager, in most situations bed bug management involves extensive product applications.
Some of the keys to successfully managing bed bug infestations in these apartments are:
• Know the type of construction, e.g., frame, concrete and steel, common utility chases, common heating elements, etc.  Construction affects possible movement in the structure.
• Thoroughly inspect infested units and ALL surrounding units. The affected unit (reporting the problem) may not be the source or focus unit.  In apartment complexes with a history of bed bug infestations a property-wide inspection should be conducted — some tenants for a variety of reasons do not report infestations to management.
• Preparation for treatment is one of the major keys to success. Everything should be removed from the closets and away from the walls. Beds and mattresses should be taken apart. Toys and clothes must be picked up.  Bedding should be washed concurrent with treatment — not several days later.  In moderately to heavily infested units pull the carpet away from the baseboard – carpet tack is a great place for the bugs to hide and remain relatively protected from sprays unless you soak the area thoroughly.  Use an IGR with your initial application.
• To avoid treating bedding suggest that mattresses and box springs be encased in sealable bags – a nice add-on product you can supply.
• Plan on spending 30 or more minutes thoroughly treating EVERY conceivable crack and crevice in a small apartment.  Plan on at least one to two follow-up treatments.
• Properties that have had a history of bed bug infestations should be placed on rotary service so that all units are inspected for all pests at least once and preferably twice per year.
Unless you can control all of these elements (you can’t) as well as introduction of bed bugs from outside sources don’t guarantee eradication of bed bugs from apartments – there is no silver bullet.

The author is president of Innovative Pest Management, Brookeville, Md. He can be reached at 301/570-3900 or via e-mail at rkramer@giemedia.com.