Effect of extreme temperatures on the performance of Lilioceris cheni (Chrysomelidae), a biological control agent of air potato in Louisiana

Invasive species are a significant threat to urban and natural ecosystems worldwide, and have resulted in significant losses to agriculture, forestry, and recreation. Air potato vine (Dioscorea bulbifera L.) which is native to Africa and Asia, is an invasive species that affects many ecosystems in southern US including Florida and Louisiana. A biological control program was initiated in 2011 in Florida and 2016 in Louisiana with the release of Air potato beetle (Lilioceris cheni Gressit and kimoto) (Coleoptera: Chrysomelidae). The beetle has proven to effectively reduce air potato growth and reproduction in Florida and has shown some promising results in Louisiana. However, further studies are required to better understand how abiotic factors influence the efficacy of L. cheni in Louisiana. The objectives of this study were to determine how extreme temperatures experienced in winter months affect beetle performance. Thermal limits and supercooling points of beetle adults were determined using ARCTIC SC100-A28 Temperature Controlled Refrigerated Bath. To determine overwintering of L. cheni, adult survival was recorded inside field cages from November 2019 to May 2020 in Baton Rouge, Louisiana. Results from this study will be used to assist scientists and stakeholders during the implementation of biological control of air potato throughout Louisiana and neighboring states.