title: No sex-related differences in mortality in bed bugs (Hemiptera: Cimicidae) exposed to deltamethrin, and surviving bed bugs can recover.
abstract: Exposure of a pyrethroid-susceptible strain of bed bugs, Cimex lectularius L. (Hemiptera: Cimicidae) to varying concentrations of deltamethrin for 24 h indicated no significant difference in mortality between males, females, and nymphs at 24 nor at 168 h postexposure when bed bugs were removed to untreated surfaces at 24 h. In addition, many bed bugs classified as morbid or moribund at 24 h and removed to untreated surfaces at this time, recovered by 336 h (2 wk) and were capable of feeding when given the opportunity. Adult female bed bugs that survived were able to lay eggs and the resulting nymphs blood-fed. By contrast, all bed bugs classified as morbid or moribund at 24 h that remained on deltamethrin-treated surfaces for 336 h either died or were still classified as morbid or moribund at the end of this time. No bed bugs classified as morbid or moribund blood-fed when given the opportunity at 2 wk, regardless of whether they remained on the treated surfaces or were removed to untreated surfaces. A power analysis demonstrated we would have detected even moderate differences in mortality between males and females, had differences existed. Therefore, using males exclusively in efficacy assays is a suitable strategy to preserve females for laboratory colony purposes. Results also indicated there is little reason to assess efficacy beyond 1 wk, even when bed bugs are exposed for only 24 h.
authors.affiliation: Invasive Insect Biocontrol and Behavior Laboratory, USDA-ARS, 10300 Baltimore Ave., Bldg. 1040, Room 2, Beltsville, MD 20705, USA. mark.feldlaufer@ars.usda.gov
authors.forename: Mark F
authors.initials: MF
authors.lastname: Feldlaufer
authors.forename: Kevin R
authors.initials: KR
authors.lastname: Ulrich
authors.forename: Matthew
authors.initials: M
authors.lastname: Kramer
mesh_terms: D000818:Animals; D001511:Bedbugs / Q000235:genetics; D004305:Dose-Response Relationship, Drug; D005260:Female; D007306:Insecticides; D008297:Male; D009570:Nitriles; D009758:Nymph / Q000235:genetics; D011722:Pyrethrins; D012727:Sex Characteristics; D023382:Toxicity Tests, Acute / Q000379:methods*
chemical_list: D007306:Insecticides; D009570:Nitriles; D011722:Pyrethrins; C017180:decamethrin