title: Evidence of Tolerance to Silica-Based Desiccant Dusts in a Pyrethroid-Resistant Strain of Cimex lectularius (Hemiptera: Cimicidae).
abstract: Insecticide resistance in bed bugs (Cimex lectulariusandCimex hemipterus) has become widespread, which has necessitated the development of new IPM (Integrated Pest Management) strategies and products for the eradication of infestations. Two promising options are the diatomaceous earth and silica gel-based desiccant dusts, both of which induce dehydration and eventual death upon bed bugs exposed to these products. However, the impact of underlying mechanisms that confer resistance to insecticides, such as cuticle thickening, on the performance of these dusts has yet to be determined. In the present study, two desiccant dusts, CimeXa Insecticide Dust (silica gel) and Bed Bug Killer Powder (diatomaceous earth) were evaluated against two strains ofC. lectularius; one highly pyrethroid-resistant and one insecticide-susceptible. Label-rate doses of both products produced 100% mortality in both strains, albeit over dissimilar time-frames (3-4 days with CimeXa vs. 14 days with Bed Bug Killer). Sub-label rate exposure to CimeXa indicated that the pyrethroid-resistant strain possessed a degree of tolerance to this product, surviving 50% longer than the susceptible strain. This is the first study to suggest that mechanisms conferring resistance to pyrethroids, such as cuticular thickening, may have potential secondary impacts on non-synthetic insecticides, including desiccant dusts, which target the bed bug's cuticle.
authors.affiliation: Department of Medical Entomology, University of Sydney, Westmead Hospital, Westmead, NSW 2145, Australia. dlil7680@uni.sydney.edu.au.
authors.forename: David G
authors.initials: DG
authors.lastname: Lilly
authors.affiliation: Department of Medical Entomology, University of Sydney, Westmead Hospital, Westmead, NSW 2145, Australia. cameron.webb@health.nsw.gov.au.|Department of Medical Entomology, Pathology West-ICPMR Westmead, Westmead Hospital, Westmead, NSW 2145, Australia. cameron.webb@health.nsw.gov.au.
authors.forename: Cameron E
authors.initials: CE
authors.lastname: Webb
authors.affiliation: Department of Medical Entomology, Pathology West-ICPMR Westmead, Westmead Hospital, Westmead, NSW 2145, Australia. stephen.doggett@health.nsw.gov.au.
authors.forename: Stephen L
authors.initials: SL
authors.lastname: Doggett
keywords: Cimex; bed bugs; insecticide resistance