Release and distribution of Lilioceris cheni (Coleoptera: Chrysomelidae), a biological control agent of air potato (Dioscorea bulbilfera: Dioscoreaceae), in Florida

Authors: OVERHOLT, WILLIAM - University Of Florida; Rayamajhi, Min; ROHRIG, ERIC - Florida Department Of Agriculture And Consumer Services; Hight, Stephen; Dray, F Allen; Lake, Ellen; Smith, Melissa; HIBBARD, KENNETH - Florida Department Of Agriculture And Consumer Services; BHATTARAI, GANESH - University Of Florida; Bowers, Kristen; POFFENBERGER, RYAN - Florida Department Of Agriculture And Consumer Services; CLARK, MOLLY - Florida Department Of Agriculture And Consumer Services; CURRY, BETH - Florida Department Of Agriculture And Consumer Services; STANGE, BERNADETTE - University Of Florida; CALISE, ELIZABETH - University Of Florida; Wasylik, Tracey; Martinez, Cristina; Leidi, Jorge

Submitted to: Biocontrol Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/28/2016
Publication Date: 6/17/2016
Citation: Overholt, W.A., Rayamajhi, M.B., Rohrig, E., Hight, S.D., Dray Jr, F.A., Lake, E.C., Smith, M., Hibbard, K., Bhattarai, G., Bowers, K.E., Poffenberger, R., Clark, M., Curry, B., Stange, B., Calise, E., Wasylik, T.K., Martinez, C.M., Leidi, J.G. 2016. Release and distribution of Lilioceris cheni (Coleoptera: Chrysomelidae), a biological control agent of air potato (Dioscorea bulbilfera: Dioscoreaceae), in Florida. Biocontrol Science and Technology. 26:1087-1099.

Interpretive Summary: From 2012 to 2015, 429,668 Lilioceris cheni Gressit and Kimoto (Coleoptera: Chrysomelidae) were released in Florida for biological control of air potato [Dioscorea bulbilfera L. (Dioscoreaceae)]. The distribution of releases was highly clustered, with several areas of high density releases and other regions with few releases. In the fall of 2015, a statewide survey was conducted at 113 randomly selected air potato infestations to determine the spatial distribution of the beetles. Adult beetles were found at 75% of locations searched. Lilioceris cheni feeding damage was found at 86% of locations. The highest levels of damage were encountered in a wide longitudinal band through peninsular Florida from the Fort Myers area in the southwest to Jacksonville in the northeast. Beetle damage was low in the Florida panhandle where air potato was relatively uncommon and fewer beetles had been released. Beetle damage was also low in far south Florida, despite high numbers of beetle releases. Beetles traveled an average of 9.5 km from the nearest release site to survey sites with a maximum distance of nearly 67 km. The rate of spread was estimated at 8.2 km/year under the assumption that beetles present at survey sites migrated from the nearest release site. Air potato vines produced fewer aerial tubers, the vegetative propagule of air potato, as foliar damage due to L. cheni increased. The results suggest that future research efforts should focus on determining the biotic and abiotic factors that may be limiting establishment in some areas of Florida.

Technical Abstract: From 2012 to 2015, 429,668 Lilioceris cheni Gressit and Kimoto (Coleoptera: Chrysomelidae) were released in Florida for biological control of air potato [Dioscorea bulbilfera L. (Dioscoreaceae)]. The spatial distribution of releases was highly aggregated, with several areas of high density releases and other regions with few releases. In the fall of 2015, a statewide survey was conducted at 113 randomly selected air potato infestations in order to determine the spatial distribution of L. cheni. Adult beetles were found at 75% of locations searched, and damage due to L. cheni was found at 86% of locations. Highest levels of damage were encountered in a wide longitudinal band through peninsular Florida from the Fort Myers area in the southwest to Jacksonville in the northeast. Beetle damage was low in the Florida panhandle where air potato was relatively uncommon and fewer beetles had been released, and in far south Florida, despite high numbers of beetle releases. On average, beetles traveled 9.5 km from the nearest release site to survey sites with a maximum distance of nearly 67 km. The rate of spread was estimated at 8.2 km/year under the assumption that beetles present at survey sites migrated from the nearest release site. Air potato vines produced fewer aerial tubers, the vegetative propagule of air potato, as foliar damage due to L. cheni increased. The results suggest that future research efforts should focus on determining the biotic and abiotic factors that may be limiting establishment in some areas of Florida.