Long-lasting insecticide treated netting affects reproductive output and mating behavior in Tribolium castaneum (Coleoptera: Tenebrionidae) and Trogoderma variabile (Coleoptera: Dermestidae)

Authors: Gerken, Alison; Campbell, James - Jim; ABTS, SHELBY; ARTHUR, FRANKLIN - RETIRED ARS EMPLOYEE; Morrison, William - Rob; Scheff, Deanna

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/28/2021
Publication Date: 11/3/2021
Publication URL: https://handle.nal.usda.gov/10113/7598754
Citation: Gerken, A.R., Campbell, J.F., Abts, S.R., Arthur, F.H., Morrison III, W.R., Scheff, D.S. 2021. Long-lasting insecticide treated netting affects reproductive output and mating behavior in Tribolium castaneum (Coleoptera: Tenebrionidae) and Trogoderma variabile (Coleoptera: Dermestidae). Journal of Economic Entomology. https://doi.org/10.1093/jee/toab204.
DOI: https://doi.org/10.1093/jee/toab204

Interpretive Summary: Preventing insects from infesting post-harvest products is one of the key tenets of a good integrated pest management (IPM) plan. Among prevention techniques is the use of netting, which can be used to exclude insects from entering facilities or products. However, netting that serves as a complete barrier to insect movement may not provide sufficient air flow and can become easily clogged in dusty environments. Long-lasting insecticide treated netting (LLIN) has a larger mesh size and rather than being a physical barrier uses a chemical insecticide to reduce insect ability to disperse and colonize after exposure. In evaluating the sublethal effects of short duration exposure to LLIN a significant reduction in number of offspring produced was found when either male or female red flour beetle were exposed to netting for five minutes. There was no difference in how long adult red flour beetles lived after a short 5-minute exposure to the netting, but due to the reduced progeny production overall population size was predicted to decrease over time. For the warehouse beetle, exposure to the netting as larvae did not significantly decrease the number of offspring produced for females or males exposed to LLIN, but there was a predicted significant decline in population growth over time for insects exposed to LLIN due to trending declines in offspring output. Exposure to the netting had impacts on red flour beetle male mating behavior, but not female behavior, with netting exposed males attempting to mate for longer. The results from this study support the use of LLIN within post-harvest facilities as part of an IPM strategy to reduce insects entering and colonizing.

Technical Abstract: Preventing insect infestations is a critical component for establishing a pest management plan for stored product insects. Long-lasting insecticide treated netting (LLIN) is a potential tool to reduce insect movement by providing a chemical barrier, where insects may be able to physically pass through but ultimately die after exposure to the netting. Sublethal effects, such as reduced movement immediately after exposure and reduced ability to colonize have been reported. Here we examine the sublethal effects of exposure to LLIN on two beetle species, Trogoderma variabile Ballion and Tribolium castaneum Herbst. We found that both female and male T. castaneum exposed to LLIN produced significantly less adult progeny than those exposed to untreated netting. Adult progeny output did not differ for T. variabile, but survivorship increased in T. variabile females exposed to LLIN. Importantly, the overall net reproductive rate was significantly decreased for both T. variabile and T. castaneum. The number of copulation attempts did not differ between males or females exposed to LLIN compared to untreated netting, but males exposed to LLIN showed increased durations of attempted and successful copulation events. This research demonstrates that the implications of LLIN exposure extend past direct mortality, with sublethal effects on reproductive output potentially increasing the effectiveness of this tool for preventing insect infestations.