TOWARDS IMPLEMENTATION OF A NOVEL FUNGAL BIOPESTICIDE FOR IPM OF BED BUGS

Over the past decade, bed bug infestations have grown virtually exponentially in both North America and Europe. Although the exact reasons for this recent resurgence are unclear, the rise in bed bug infestations has been linked to increased international travel, changes in pest management practices and the wide scale spread of insecticide resistance. Current bed bug control measures rely heavily on the use of pyrethroid insecticides. However, insecticide resistance, together with concerns over extensive use of chemicals in the domestic environment, creates a need for alternative methods of bed bug control. One approach is the formulation of fungal entomopathogens as novel biopesticides. Entomopathogenic fungi lend themselves to development as biopesticides because, like many conventional chemical insecticide active ingredients, they act through contact. Fungal species such as Beauveria bassiana and Metarhizium anisopliae are capable of infecting a broad range of insect hosts and several biopesticide products have been developed for use in horticulture and agriculture, particularly as components of Integrated Pest Management (IPM). Bed bugs are cryptic creatures that hide in the safety of a harborage during the day, and venture out only in search of a blood-meal. This cryptic behavior poses a problem for insecticide treatments that require direct contact to be effective. The aim of this project is to build on the considerable progress made in our lab towards the development of novel oil formulations and barrier treatments of B. bassiana (I93-825) and Metarhizium anisopliae (ESF1) for the control of bed bugs in domestic dwellings. We have demonstrated that by spraying an oil formulation of fungal conidia of B. bassiana onto a surface such at jersey knit cotton, we can infect bed bugs through short term exposure to the pre-sprayed substrate. Exposed bed bugs die within 3-4 days following brief contact with the sprayed surface, and additionally, carry conidia back to their harborages to infect those bed bugs that would otherwise be unaffected by a spray treatment. To prepare this technology for field-testing, we will compare the virulence of two promising commercial (EPA registered) fungal entomopathogens, to bed bugs over the temperature range of 15-30oC, evaluate the relative transfer/pick-up of conidia sprayed in oil formulations to bed bugs exposed to a range of candidate textile substrates, and design prototype spore delivery technologies for future field evaluation. Through achieving these objectives, we will be contributing to the science base for management of bed bugs and provide an effective, safe, alternative to chemical pesticides. This will contribute to safeguarding human health through the reduction in the use of chemicals in the home. Furthermore, we are confident that this technology will provide superior control of bed bug via auto-dissemination of conidia to bed bugs in inaccessible areas and provide longer term protection from re-infestation via barrier treatments to prevent immigration of bed bugs from neighboring properties.