Monday, October 17, 2011

Bed Bug Resurgence

Bed Bugs are Re-emerging It's Time to Fight Back

Bedbugs been with us longer than you think.

Bed Bugs, Cimex Lectularius, have been with man since we slept in caves. The earliest historical citations about them go back to 423 B.C. In the United States, bed bugs came over with the first explorers and were a problem until the introduction of DDT in the late 1930’s provided the first major advance in bed bug control. Following on the heels of DDT were organophosphates which also provided excellent control.

Throughout the years, an evolving regulatory environment has removed or limited the tools that were available for controlling bed bugs causing infestations to ebb and flow.

New ideas to fight the resurgence of an old foe.

Recently, bed bug infestations have enjoyed a resurgence, to the point where bed bugs are like a new pest. It is not often the pest control industry is faced with new pests to deal with. The occasional introduced ant species can be challenging, but in general these are localized problems. Bed bugs, however, are a nationwide pest problem in the U.S.

The resurgence of this age old pest has become a significant problem in dorm rooms, hotels, apartments, and permanent residences alike. Today’s mobile society and the loss of key pesticide tools present a unique challenge for Pest Management Professionals trying to successfully control bed bugs. A variety of methods need to be implemented for a successful management program.

Knock Bed Bugs down and keep them down.

Conventional adulticides are an important tool, as well as sanitation and exclusion. Other important tools include Insect Growth Regulators (IGRs). IGRs have a strong history of controlling a wide variety of insects such as cockroaches and fleas. In combination with adulticides and other measures, IGRs keep insect populations under control by breaking the life cycle and preventing infestations from rebounding.

Gentrol is an IGR that is well known to Pest Management Professionals (PMPs). Gentrol was introduced to the industry in the id 80’s and has been used to successfully control cockroaches, stored product pests, drain and fruit flies. The recent addition of bed bugs to the Gentrol label offers PMPs another tool in the challenge to control bed bugs.

Additional points of interest for fighting bed bugs.

The primary mode of action for Gentrol is to affect bed bug reproduction. When reproduction is affected the insect population declines, reducing the infestation.

Gentrol works on bed bugs, as in cockroaches, by preventing the nymph from developing into reproductively functioning adults. Electron microscopy shows that in cockroaches and in bed bugs the organs responsible for normal copulation and reproduction do not develop. In the case of male bed bugs, the paramere, or reproductive organ, fails to develop normally. As a result, successful copulation cannot occur.

In addition to reproductive anomalies, there is research showing that some nymphs exposed to Gentrol die prior to molting into adults.

There is information in the public domain that suggest Gentrol causes bed bug females to produce more eggs. This was a one time evaluation where immature bed bugs that escaped being affected by Gentrol produced more eggs than the control replicates. These females that produced more eggs were not exposed to Gentrol at the time they were reproductive.

IGRs can affect fecundity – i.e. adult female insects exposed to IGRs generally produce fewer eggs than unexposed females. According to the Monograph of Cimicidae, bed bug egg production varies between individuals and continues up to 12 weeks after the first blood meal. Egg production during that first week after a blood meal ranged from 5 to 16 eggs per week. Egg production increased as the females aged with as many as 27 eggs produced per week during the 12 week observation period.

In studies generated to satisfy EPA registration requirements, Gentrol provided efficacy by inhibiting the development of the next generation of nymphs by 92%. In other words, nymphs exposed to a Gentrol treatment were unable to reproduce. Mortality was also observed in this study where 66% of the exposed nymphs failed to survive to adults. Of those surviving to adults, reproduction was significantly reduced by 92% from the untreated control population. There as an average of 3 nymphs produced vs. an average of 61 produced in the untreated control group.

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