Changes in latitude: overwintering survival of two Lilioceris cheni(Coleoptera: Chrysomelidae) biotypes in Florida

Authors: Smith, Melissa; OVERHOLT, WILLIAM - University Of Florida; Lake, Ellen; DIAZ, RODRIGO - Louisiana State University; MANRIQUE, VERONICA - Southern University; Hight, Stephen; ROHRIG, ERIC - Florida Department Of Agriculture And Consumer Services; MINTEER, CAREY - University Of Florida; Wheeler, Gregory; Rayamajhi, Min; Bowers, Kristen; KERR, CHRISTOPHER - Florida Department Of Agriculture And Consumer Services

Submitted to: Biocontrol Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/12/2018
Publication Date: 2/23/2018
Citation: Smith, M., Overholt, W.C., Lake, E.C., Diaz, R., Manrique, V., Hight, S.D., Rohrig, E., Minteer, C., Wheeler, G.S., Rayamajhi, M.B., Bowers, K.E., Kerr, C. 2018. Changes in latitude: overwintering survival of two Lilioceris cheni(Coleoptera: Chrysomelidae) biotypes in Florida. Biocontrol Science and Technology. 28(3):293-306. https://doi.org/10.1080/09583157.2018.1441371.
DOI: https://doi.org/10.1080/09583157.2018.1441371

Interpretive Summary: Lilioceris cheni, a chrysomelid beetle, is a biological control agent for the invasive vine, Dioscorea bulbifera. Two biotypes of the beetle are now available for release. We conducted four seasons of overwintering trials to determine which biotype fares best in which areas in Florida. We initially hypothesized that Chinese beetles would do best in south Florida and Nepalese beetles would do best in the more northern parts of the invaded range. Nepalese beetles survived significantly better than Chinese beetles overall. Beetles survived better in 2013, the first year of the study and beetles generally survived best in Fort Pierce. These data will aid current mass rearing and release efforts by providing much needed information regarding the best biotype for each region.

Technical Abstract: Lilioceris cheni a successful biological control agent on the invasive yam, Dioscorea bulbifera in many areas in Florida, Georgia, Alabama and Louisiana. Two biotypes are available for release and come from significantly different centers of origin. The Nepalese biotype was collected at higher altitude and latitude sites, whereas the Chinese biotype was collected at slightly lower latitude and lower altitude. We hypothesized that Nepalese beetles would survive winter better in north Florida and that Chinese beetles would overwinter better in the subtropical south Florida. We established sites in Homestead, Fort Pierce, Gainesville and Tallahassee, Florida to gauge the overwintering survival of each biotype. Beetles overwintered in each site for one to three seasons, were collected and followed for reproduction. In the final year of the experiment, we extracted fat bodies to determine effects of biotype and site. Nepalese beetles overwintered significantly better overall. Beetles survived better in the first study year (2013-2014). Both biotypes reproduce very well after surviving winter and beetles in Fort Pierce survive better than beetles in other regions and maintain a higher fat body. Nepalese beetles may have a wider ecological envelope – a decided advantage for a large region such as peninsular Florida. We suggest that current release programs incorporate Nepalese beetles into their protocol to increase overwinter survival and establishment.