Optimization of 13-tetradecenyl acetate sex pheromone for trapping Melanotus communis (Coleoptera: Elateridae)

Authors: SCHOEPNNER, EMMA - North Carolina State University; MILLAR, JOCELYN - University Of California, Riverside; KUHAR, THOMAS - Virginia Polytechnic Institution & State University; DOUGHTY, HELENE - Virginia Polytechnic Institution & State University; CHERRY, RON - University Of Florida; HALL, GRACE - North Carolina State University; KNOWLES, CAITLYN - North Carolina State University; Williams, Livy; HUSETH, ANDERS - North Carolina State University

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/5/2023
Publication Date: 5/19/2023
Citation: Schoepnner, E., Millar, J., Kuhar, T., Doughty, H., Cherry, R., Hall, G., Knowles, C.G., Williams III, L.H., Huseth, A.S. 2023. Optimization of 13-tetradecenyl acetate sex pheromone for trapping Melanotus communis (Coleoptera: Elateridae). Journal of Economic Entomology. https://doi.org/10.1093/jee/toad086.
DOI: https://doi.org/10.1093/jee/toad086

Interpretive Summary: Subterranean insects are serious pests of many crops throughout the world. The corn wireworm, is an economically important pest of root and tuber crops in the United States. Recent discovery of the corn wireworm sex attractant provides a new method to monitor this pest during the adult stage. Early studies with this attractant showed that different trapping methods might enhance catch and improve trap servicing. We hypothesized that optimizing trap placement and type of trap may increase corn wireworm capture relative to the attractant-based pitfall trapping that is currently used. We conducted field studies in North Carolina, Virginia, South Carolina, and Florida to compare captures among in-ground pitfall traps, on-ground pitfalls, elevated pitfalls (waist-high), or elevated sticky cards (waist-high) and tested attractant lure longevity by aging the lures for several time periods prior to trap deployment in the field. Results highlight large variation in corn wireworm abundance across the four states. We showed that attractant traps positioned waist-high caught the most beetles. Also, lures that were aged for fewer weeks attracted significantly more beetles, with 0- and 2-week-old lures capturing the greatest numbers. Our findings indicate that optimizing the sex attractant with appropriate trap placement plays an important role in detecting and monitoring this pest. Advancements in attractant baited trap deployment will allow for more robust monitoring programs for corn wireworm, and subsequently, the development of pest management strategies that have previously been unrealistic for growers with detrimental wireworm populations.

Technical Abstract: The corn wireworm, Melanotus communis Gyllenhal (Coleoptera: Elateridae), is an economically important larval pest of root and tuber crops in the United States. Previous work to estimate field-level abundance of M. communis has focused on grain-based larval baits placed in soil. However, this sampling method is labor intensive and may not estimate population size accurately. Recent discovery of the M. communis sex pheromone, 13-tetradecenyl acetate, provides a new method to monitor this pest during the adult stage. Early studies with this pheromone showed that different trapping methods might enhance catch and improve trap servicing. We hypothesized that optimizing trap placement and type of trap may increase M. communis capture relative to the pheromone-based pitfall trapping that is currently used. We had two objectives for this study: 1) to compare pheromone captures among in-ground pitfall traps, on-ground pitfalls, elevated pitfalls (1 m), or elevated sticky cards (1 m); and 2) test lure longevity by aging the lures outdoors at 8-, 6-, 4-, 2-, and 0-week intervals prior to trap deployment in the field. Experiments were conducted in North Carolina, Virginia, South Carolina, and Florida during the 2021 and 2022 field seasons. Results highlight large variation in M. communis abundance across the four states. We showed that 1 m elevated pheromone traps caught the most beetles. The age of the lure prior to deployment had a significant effect on trap catch. The lures that were aged for fewer weeks attracted significantly more beetles, with 0- and 2-week-old lures capturing the greatest numbers.