Susceptibility of Different Life Stages of Tribolium confusum (Coleoptera:Tenebrionidae) and Oryzaephilus surinamensis (Coleoptera: Silvanidae) to Cold Treatment

摘要

Laboratory tests were carried out to examine the efficacy of different exposure intervals (2 h, 4 h, 8 h, 1 d, 2 d, 3 d, and 7 d) on different life stages (adults, pupae, larvae, and eggs) of Tribolium confusum Jacquelin du Val (Coleoptera:Tenebrionidae), the confused flour beetle, and Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae), the saw-toothed grain beetle (adults, larvae, and eggs) to 0, -5, -10, and -15 degrees C. Larvae and pupae of T confusum were more cold-tolerant than eggs or adults. Exposure to temperatures of -10 degrees C for 1 d will kill nearly 100% of all life stages of T confusum. O. surinamensis was more cold-tolerant than T confusum. Adults of O. surinamensis were not killed when exposed for 1 d at -5 degrees C, but egg hatch was drastically reduced after 2 h of exposure at the same temperature. Eggs and adults of O. surinamensis were more cold-tolerant than larvae. Our study indicates that target insect species and life stage, temperature, and exposure interval should all be considered when cold treatment is selected as a control strategy against T confusum and O. surinamensis. Facility managers can use these data in planning cold treatments.