|Arthur, Franklin - Frank|
Submitted to: Journal of Pest Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/20/2018
Publication Date: N/A
Citation: N/A Interpretive Summary: Recent studies show potential for using a specific cold temperature of 0°F to control beetle and psocid pests of stored products, however, there are no available data to show the relationship between temperature and exposure time, could be manipulated to determine temperature-time combinations that could be utilized by industry in practical applications. Also, data are lacking for susceptibility of different life stages of the Indianmeal moth, a major pest of processed food products. We conducted studies by exposing different life stages of a psocid species (Lipocelis bostrychophila) and the Indianmeal moth to temperatures ranging from 5 to 32 °F for 1-7 days. The most cold-tolerant stage of the Indianmeal moth was the larval stage. The most-cold tolerant stage of the psocid was the egg stage, but in general all life stages were more tolerant to the cold temperatures compared to the life stages of the Indianmeal moth. For both species, mortality increased with increasing exposure time. Results show that cold temperatures would be a viable strategy for control of these species, however, the exposure time must be carefully monitored to ensure complete kill. Results of this study are especially applicable to organic storage of bulk processed food products, as they show the feasibility of using cold temperatures as an alternative to insecticides for insect pest management.
Technical Abstract: The insecticidal effect of low temperatures for the control of all life stages of two stored product insects, Plodia interpunctella and Liposcelis bostrychophila, was evaluated under laboratory conditions. The temperatures tested were 0, -5, -10 and -15 °C, and, at these temperatures, the insects were exposed for 2, 4 and 8 h and also for 1, 2, 3 and 7 d. Regarding P. interpunctella, the most cold-tolerant life stage was larvae, given that 2 d of exposure were needed for a complete (100 %) larval mortality at –10 ºC. Moreover, all larvae were dead at -15 oC even after 2 h of exposure. In contrast to results from previous studies, eggs of P. interpunctella were susceptible to cold, as mortality was complete after 7 d, 1 d, 2 h and 2 h at 0, -5, -10 and -15 ºC, respectively. Liposcelis bostrychophila was by far less susceptible than P. interpunctella. For this species, adults were still alive even after 7 d at -10 °C, while complete mortality was achieved only after 1 d at -15 °C. Interestingly, eggs of L. bostrychophila were the most cold tolerant life stage, as survival was observed even after 3 d at -15 °C. The results of the present study provide the first data set on which all life stages of P. interpunctella and L. bostrychophila are examined towards their susceptibility to cold treatments in a standardized series of exposures and temperature levels. These results are expected to further encourage the “real world” application of cold treatments for the disinfestation of durable stored products.