Laboratory Insecticide Efficacy Trials of Lethal Harborages for Control of the Common Bed Bug, Cimex lectularius (Hemiptera: Cimicidae)

SIMPLE SUMMARY: Over the past 20 years, there has been a worldwide resurgence in the nuisance biting insects known as bed bugs. The resurgence is due to the development of insecticide resistance, such that modern bed bugs are very hard to kill. This also means that control is expensive, and not everyone has the financial resources to pay for eradication. In an effort to develop cheaper control solutions, we investigated the use of “lethal harborages”. Here, pieces of cardboard were treated with different insecticides, two strains of bed bugs (one that is easy to kill and one that is resistant) were allowed to enter the treated cardboards, and mortality was recorded. The cardboard treated with silica dioxide were the most effective, causing 100% of the bugs to die within 14 to 17 days when using the highest dose. This silica dioxide dust was also tested in an artificial environment. By day 21, all the bugs in the treated settings were eliminated. These “lethal harborages” were highly effective in the laboratory and are a potential low-cost solution as part of an overall bed bug control plan. ABSTRACT: Over the past two decades, there has been a worldwide resurgence in the bed bugs Cimex lectularius L. and Cimex hemipterus (F.). This is primarily due to insecticide resistance, making bed bug management and eradication challenging and expensive. To address the need for more affordable control solutions, “lethal harborages” were explored. Cardboard squares were treated using insecticidal dusts at different dosage levels, including silica dioxide, diatomaceous earth, deltamethrin, permethrin, and fipronil. Two strains of C. lectularius, one susceptible and one resistant, were allowed to enter the treated harborages, and mortality rates were recorded daily. The silica dioxide products proved to be the most efficacious, consistently achieving 100% mortality between 14–17 d at the highest dose. An artificial environment trial using the “new ChinChex(®)” formulation of silica dioxide resulted in the complete elimination of bed bugs in the treated harborages within 21 d. These findings suggest that lethal harborages, especially those impregnated with silica dioxide, offer a cost-effective solution that could be incorporated into broader integrated bed bug management strategies. This approach may help alleviate the burden of bed bug infestations in economically disadvantaged communities.