Challenges in assessing repellency as an integrated pest management tool to protect stored grains, using the global pest Tribolium castaneum

Authors: RAULT, LESLIE - University Of Nebraska; Morrison, William - Rob; Gerken, Alison; BINGHAM, GEORGINA - University Of Nebraska

Submitted to: Insects
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/18/2024
Publication Date: 8/20/2024
Citation: Rault, L.C., Morrison III, W.R., Gerken, A.R., Bingham, G.V. 2024. Challenges in assessing repellency as an integrated pest management tool to protect stored grains, using the global pest Tribolium castaneum. Insects. 15(8): 626. https://doi.org/10.3390/insects15080626.
DOI: https://doi.org/10.3390/insects15080626

Interpretive Summary: Food security is an increasingly pressing global issue, and by 2050, food production will not be sufficient to feed the growing population. Multiple species of stored product insects colonize raw grain after it is harvested from the field and also finished food products, resulting in substantial economic losses every year. Although multiple pest management strategies exist for controlling stored product insects, including insecticides and fumigation, an underexplored area of research in food facilities is repellency whereby a compound is used to deter the presence of a pest away from a commodity. The red flour beetle is a global stored-product pest with a wide range of food sources and was used in this study to assess repellency to a selection of essential oils that have previously shown repellency against other insects. A series of different behavioral assays were used to identify oils that consistently induced repellency under multiple types of behavioral experiments, such as those that caused beetles to move away from spend less time around the oil. We found that many essential oils considerably influenced T. castaneum behavior, but results varied among different types of behavioral assays and a clear candidate for repellency was not obvious. Follow-up research is needed to pinpoint effective repellents for integrated pest management practices to protect grains from colonization by stored-product pests.

Technical Abstract: Food security is an increasingly pressing global issue, and by 2050, food production will not be sufficient to feed the growing population. Part of global food insecurity can be attributed to post harvest losses, which include quantity and quality losses caused by stored-product pests, such as insects. It is thus timely to find management strategies to mitigate these losses and counteract food insecurity. The red flour beetle , Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), a global stored-product pest, with a wide range of food sources, was used in this study to assess repellency to a selection of essential oils. Multiple behaviorally-relevant methods were used to determine the efficacy of the essential oils in assays to pinpoint the most promising repellents. Experiments assessed individual and group behaviors, with or without airflow, and examined behavioral variation in distance moved and time spent away from the oil. It was found that the exposure to essential oils and conditions of experimentation considerably influenced T. castaneum behavioral response response, but a clear candidate for repellency could not be chosen based on the collected data. Follow-up research is needed to pinpoint repellents for integrated pest management practices to protect grains from stored-product pests, and to justify their use in and around commodities.