D3016: (1st Place) The efficacy of insecticide-incorporated netting for preventing maize weevils (Coleoptera: Curculionidae) from infesting brown rice

Commodities are susceptible to insect infestation at any point along the post-harvest supply chain. The maize weevil (Sitophilus zeamais) is a stored grain insect that has a negative impact on both the quantity and quality of grains. To mitigate insect infestation in stored grains, a variety of insect control tactics are used. Long-lasting insecticide-incorporated netting (LLIN) is used as a part of a strategy to control the spread of malaria in tropical regions. Recent research has demonstrated that LLIN can significantly increase the mortality of stored product insects. However, less is known about how LLIN can act as a barrier during the storage of grain commodities. The goal of this study was to determine the efficacy of LLIN in preventing maize weevil from infesting brown rice after nets were placed in a rice mill over a 6-month period. Two LLIN types were used with different active ingredients, one with 0.4% deltamethrin and the other with 0.34% α-cypermethrin. A control net with no insecticides was also used. Insects were counted as alive, knocked down, or dead over a 24-hour time exposure. The insects’ ability to penetrate the netting was also observed. Nets incorporated with insecticides provided a barrier for insects with minimal contact to brown rice samples. Mortality was also higher in the LLIN treatment compared to the controls. This research highlights the potential use of LLIN as part of an integrated pest management tool for preventing insect infestations in rice.