Attraction of the air potato leaf beetle, Lilioceris Cheni (Coleoptera: Chrysomelidae) to leaf volatiles of the air potato, Dioscorea bulbifera

Authors: GRIESHEIMER, JESSICA - University Of Florida; Gaffke, Alexander; MINTEER, CAREY - University Of Florida; Mass, John; HIGHT, STEPHEN - Retired ARS Employee; MARTINI, XAVIER - University Of Florida

Submitted to: Journal of Chemical Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/19/2023
Publication Date: 6/6/2023
Citation: Griesheimer, J.L., Gaffke, A.M., Minteer, C., Mass, J.L., Hight, S., Martini, X. 2023. Attraction of the air potato leaf beetle, Lilioceris cheni (Coleoptera: Chrysomelidae) to leaf volatiles of the air potato, Dioscorea bulbifera. Journal of Chemical Ecology. https://doi.org/10.1007/s10886-023-01436-z.
DOI: https://doi.org/10.1007/s10886-023-01436-z

Interpretive Summary: Air potato is a non-native invasive weed spreading across the southeastern United States. Because of its invasive nature, the air potato leaf beetle was introduced to help control this plant. As its name implies, this beetle can only feed on air potato. The air potato beetle has been very successful at controlling the plant, however, some patches of the weed seem to be able to avoid detection and feeding from the beetle. USDA-ARS scientists with the Insect Behavior and Biocontrol Research Unit in Tallahassee, FL in collaboration with researchers from the University of Florida investigated ways to promote aggregation of beetles on plants that were not being controlled. Studies conducted on the plant indicated that feeding beetles caused the plant to release highly attractive odors, ultimately calling in more beetles and causing more damage to the plant. Odors responsible for beetle attraction were identified and show promise for future development into lures to actively 'herd' beetles to the plants, resulting in better control of this invasive weed.

Technical Abstract: Air potato vine, Dioscorea bulbifera L., is an invasive vine species found in the southeastern United States native to Asia and Africa. The air potato leaf beetle Lilioceris cheni (Coleoptera: Chrysomelidae), is a host specific biological control agent for D. bulbifera. In this study odor cues that control the attraction of L. cheni to D. bulbifera were investigated. The first experiment investigated the response of L. cheni to D. bulbifera leaves vs no leaves in the presence or absence of air flow. The experiment showed a significant response of L. cheni to D. bulbifera leaves in the presence of air flow with leaves placed upwind. When air flow and/or leaves were absent, L. cheni dispersed randomly between the upwind and downwind targets, indicating L. cheni uses volatiles from D. bulbifera in host selection. The second experiment investigated L. cheni response to undamaged, larval-damaged, and adult-damaged plants. Lilioceris cheni showed significant preference for conspecific damaged plants than undamaged plants in the wind tunnel but did not discriminate between larvae-damaged or adult-damaged plants. The third experiment investigated volatile profiles of damaged D. bulbifera plants using gas chromatography coupled with mass spectroscopy. We found significant differences in volatile profiles between adult and larval damaged plants compared to mechanically damaged and undamaged plants, with significant increases in 11 volatile compounds. However, larval and adult-damaged volatile profiles did not differ. The information acquired during this study could be used to develop strategies to monitor for L. cheni and improve its biological control program.