Submitted to: Journal of Stored Products Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 17, 2013
Publication Date: November 6, 2013
Citation: Throne, J.E., Weaver, D.K. 2013. Impact of temperature and relative humidity on life history parameters of adult Sitotroga cerealella (Lepidoptera: Gelechiidae). Journal of Stored Products Research. 55:128-133. DOI: http://dx.doi.org/10.1016/j.jspr.2013.10.003. Interpretive Summary: The Angoumois grain moth is a pest of stored corn and other grains throughout the world. They are routinely exposed to temperatures below 70°F in regions of the U.S. where corn is grown, yet there are no data describing adult life history below 70°F. We determined longevity, fecundity, and survivorship of eggs at a range of temperatures that represent environmental conditions to which Angoumois grain moths are exposed in corn stored in the U.S. (50 to 105°F). Females and males lived as long as four weeks at 50°F. Females laid eggs at all temperatures tested, but fewer eggs were laid and hatched at temperatures below 70°F. Our results show that Angoumois grain moths can live and reproduce at temperatures below 70°F. These data will be used to develop computer models for simulating Angoumois grain moth population growth at the complete range of environmental conditions at which these insects are exposed in stored grain, and the simulation models will be used to aid in making pest management recommendations.
Technical Abstract: The Angoumois grain moth, Sitotroga cerealella (Olivier) (Lepidoptera: Gelechiidae), is a pest of stored corn, Zea mays L., and other grains throughout the world. S. cerealella are routinely exposed to temperatures below 20°C in regions of the U.S. where corn is grown, yet there are no data describing adult life history parameters below 20°C. We determined longevity, fecundity, and survivorship of eggs at a range of temperatures that represent environmental conditions to which S. cerealella are exposed in corn stored in the U.S. Longest male longevity was 31 d at 10°C, and shortest male longevity was 4 d at 35 and 40°C. Longest female longevity was 29 d at 15°C, and shortest female longevity was 5 days at 35 and 40°C. Duration of the preoviposition period was as long as 16 d at 10°C and as short as 1 d at 30 to 40°C. All females laid eggs at 20 to 30°C, 50 to 94% of females laid eggs at 15°C, and 17 to 61% of females laid eggs at 10, 35, or 40°C. Females laid the most eggs, nearly 100, at 20 and 25°C and 75% r.h., while 6 or fewer eggs were laid at 10, 35, or 40°C. 68 to 98% of eggs hatched at 20 to 30°C, while 20% or less eggs hatched at 35°C and no eggs hatched at 40°C. An average of less than one egg was laid at 10°C, but 58 to 100% of eggs hatched at 10°C. Our results emphasize the importance of including data on population growth of stored-grain insect pests at low temperatures in computer models for simulating insect population growth in grain.