Susceptibility of field-collected bed bugs in Kuwait to commonly used insecticides

The resurgence of bed bugs has been largely attributed to increasing resistance to commonly used insecticides, yet data from the Middle East remain limited. This study evaluated the susceptibility of field-collected bed bug populations from multiple regions of Kuwait to two widely used commercial insecticides, Civic and Temprid, with emphasis on temporal patterns of mortality and treatment efficacy. Bed bugs were exposed to insecticide-treated surfaces, and mortality was recorded at multiple time points from 10 minutes to 72 hours. Control groups exhibited consistently low mortality, indicating minimal mortality attributable to handling, environmental conditions, or other non-treatment factors. In contrast, exposed populations showed a pronounced, time-dependent increase in mortality. Civic induced significantly higher mortality than Temprid as early as 30 minutes post-exposure, indicating a faster initial knockdown. Although both insecticides achieved similar final mortality levels at 72 hours (∼52–54%), Civic produced stronger intermediate effects. Mortality patterns varied among populations, indicating differences in susceptibility. However, maximum mortality only marginally exceeded 50%, limiting reliable LT 50 estimation and suggesting reduced treatment effectiveness. This study provides the first evidence of low mortality responses to insecticide exposure in bed bug populations in Kuwait and highlights the need for localized mortality-based monitoring and time-resolved efficacy assessments to support effective bed bug control. • First evidence of insecticide resistance in bed bugs in Kuwait • Civic shows faster knockdown than Temprid across time points • Mortality remains below 55%, indicating reduced susceptibility • Time-dependent mortality is the dominant driver of treatment effect • Evidence supports emerging resistance in Kuwait bed bugs populations