Thermal Tolerance of the Bed Bug

Abstract:
Exploitation of very high or low temperatures for bed bug, Cimex lectularius, control can be a supporting measure or even an alternative to chemical control methods. To observe the influence of heat, groups of adults, juveniles and eggs (group size = 20 individuals) were exposed to ambient temperatures TA of 43°C and 44.6°C at exposure times of 10 to 40 min. After heat exposure, the adults and juveniles were kept at 25°C and eggs at 32°C. Bug activity was controlled following heat exposure after 7 d. All bed bugs (adults, juveniles and eggs) were dead after an exposure time of 30 min at TA 44.6 °C. At this TA, adults were less heat resistant (97.5 % survivors after 15 min heat exposure, no survivors after 20 min exposure) compared to eggs (still 17.5 % hatches after 25 min heat exposure, no hatches after 30 min exposure). To investigate the effect of cold, adult bed bugs were fed and then kept for 2, 6, 7, 8, and 9 days at a temperature of 25°C and 45 % RH. before they were transferred to 4.5°C and 55 % RH. (200 bed bugs per experiment). Bed bugs which were kept for 6 days at 25°C before they were exposed to 4.5°C had the highest survival rates (50% survivors after 99 d, n = 200). Bed bugs which were exposed to cold 2 or 9 days after their last blood meal had lower survival rates (50% survivors after 36 d and 69 d, respectively). Bed bugs stored at TA 16°C had survived longer than at 4.5°C (50% survivors after 157 d and 99 d, respectively). Data from our experiments could be useful for a better understanding of heat or cold treatment of bed bugs.