BACKGROUND: Residual insecticides interrupt the dispersal of bed bugs (Cimex lectularius, L.), but one of the issues encountered with residual applications is understanding the uptake of active residues by the insect. This study determined permethrin uptake by bed bugs walking on the ActiveGuard® Mattress Liner product, via a combination of video recording in arenas and gas chromatography analyses. RESULTS: The best model for estimating permethrin uptake utilized a covariance model (r2 = 0.469) with two factors: time of exposure (F1,55 = 2.44, P < 0.001) and distance traveled (F1,55 = 0.30, P = 0.0460). Bed bug permethrin uptake was 15.1 (95% CI: 10.3-22.1) ng insect-1 within 1 min exposure, 21.0 (15.0, 31.0) ng insect-1 within 10 min and ≈ 42 (29.8, 60.6) ng insect-1 within ≥50 min exposure. Correcting for percentage recovery, these values would be increased by a factor of 1.21. CONCLUSION: This permethrin-treated fabric provides a surface from which bed bugs begin rapidly to absorb permethrin on contact and within the first 1 cm of travel. Variability in uptake was likely a result of grooming and thigmotaxis, and future work should use quantitative methods to study behaviors and formulations that increase exposure to the toxicant.
BACKGROUND: Residual insecticides interrupt the dispersal of bed bugs (Cimex lectularius, L.), but one of the issues encountered with residual applications is understanding the uptake of active residues by the insect. This study determined permethrin uptake by bed bugs walking on the ActiveGuard® Mattress Liner product, via a combination of video recording in arenas and gas chromatography analyses. RESULTS: The best model for estimating permethrin uptake utilized a covariance model (r2 = 0.469) with two factors: time of exposure (F1,55 = 2.44, P < 0.001) and distance traveled (F1,55 = 0.30, P = 0.0460). Bed bugpermethrin uptake was 15.1 (95% CI: 10.3-22.1) ng insect-1 within 1 min exposure, 21.0 (15.0, 31.0) ng insect-1 within 10 min and ≈ 42 (29.8, 60.6) ng insect-1 within ≥50 min exposure. Correcting for percentage recovery, these values would be increased by a factor of 1.21. CONCLUSION: This permethrin-treated fabric provides a surface from which bed bugs begin rapidly to absorb permethrin on contact and within the first 1 cm of travel. Variability in uptake was likely a result of grooming and thigmotaxis, and future work should use quantitative methods to study behaviors and formulations that increase exposure to the toxicant.