|Arthur, Franklin - Frank|
Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/24/2018
Publication Date: N/A
Citation: N/A Interpretive Summary: Cold temperatures can be used to control stored product insects, but the lethal temperatures required for complete kill depend on the specific insect species and life stage, along with the time of exposure at specific temperatures. In addition, most studies are not conducted a low temperature ranges, which also affect susceptibility to cold. Exposing different life stages of the confused flour beetle and the sawtoothed grain beetle, two stored product insects that infest packaged and processed grain products, to low temperatures for different periods of time, we found that for confused flour beetle, larvae and pupae were more tolerant of cold temperatures than eggs or adults, and for sawtoothed grain beetle, eggs were the most cold-tolerant than any of the other life stages. Overall, sawtoothed grain beetle was more tolerant of cold temperatures than the confused flour beetle, however, exposures of at least 8 h to -5 F° killed all life stages of both species. Results of this study provide guidelines for using cold temperatures for controlling stored product insects, using exposure time-temperature combinations, and will be especially useful for organic storage industries.
Technical Abstract: 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, eggs) of Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae), the confused flour beetle, and O. surinamensis (L.) (Coleoptera: Silvanidae), the sawtoothed grain beetle (adults, larvae, eggs) to 0, -5, -10 and -15ºC. Larvae and pupae of T. confusum were more cold-tolerant than eggs or adults. Exposure to temperatures of -10oC 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 -5oC, 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. castaneum and O. surinamensis. Facility managers can use these data in planning cold treatments for management of these insect species.