Challenges in Assessing Repellency via the Behavioral Response by the Global Pest Tribolium castaneum to Protect Stored Grains

Abstract

Background: 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, including quantity and quality losses caused by stored-product pests like 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. Methods: Multiple behaviorally relevant methods were used to determine the efficacy of the essential oils in assays to pinpoint the most promising repellents. Experiments were used to assess individual and group behaviors with or without airflow and examined the behavioral variation in distance moved and the time spent away from the oil. Results: It was found that exposure to essential oils and conditions of experimentation considerably influenced T. castaneum’s behavioral response, but a clear candidate for repellency could not be chosen based on the collected data. Conclusions: 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.