Assessing the status of biological control of air potato (Dioscorea bulbifera) in the southeastern USA

Authors: MANRIGUE, VERONICA - Southern University; KRAUS, EMILY - Florida Department Of Agriculture And Consumer Services; SCHAFFER, CHARITY - Southern University; DIAZ, RODRIGO - Louisiana State University; KELM, CASSANDRA - Florida Department Of Agriculture And Consumer Services; POFFENBERGER, RYAN - Florida Department Of Agriculture And Consumer Services; MURRAY, ROSIE - Florida Department Of Agriculture And Consumer Services; Smith, Melissa; Dray, F Allen; Leidi, Jorge; LAKE, ELLEN - Former ARS Employee; RAYAMAJHI, MIN - Former ARS Employee; MINTEER, CAREY - University Of Florida; Mass, John; Hight, Stephen

Submitted to: Biocontrol Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/3/2023
Publication Date: 12/15/2023
Citation: Manrigue, V., Kraus, E., Schaffer, C., Diaz, R., Kelm, C., Poffenberger, R., Murray, R., Smith, M., Dray Jr, F.A., Leidi, J.G., Lake, E., Rayamajhi, M., Minteer, C., Mass, J.L., Hight, S.D. 2023. Assessing the status of biological control of air potato (Dioscorea bulbifera) in the southeastern USA. Biocontrol Science and Technology. (33)12:1173-1185. https://doi.org/10.1080/09583157.2023.2294207.
DOI: https://doi.org/10.1080/09583157.2023.2294207

Interpretive Summary: The invasive Asian air potato vine occurs throughout subtropical regions of the Gulf Coast states. It invades natural ecosystems, displacing native species and the animals that rely on them. A leaf feeding beetle was released in Florida beginning in 2011 to combat the air potato vine and reduce its negative impacts in natural areas. This study documents releases of the beetle in GA, AL, MS, LA, and TX, and reports results of surveys conducted at 136 sites during September-October 2019 to assess beetle populations and the damage they're causing to vine populations. Overall, beetles were thriving in most locations, reducing vine growth and size of aerial "potatoes" (called bulbils) by which reproduction occurs in the USA.

Technical Abstract: Air potato, Dioscorea bulbifera L. (Dioscoreaceae), is an invasive vine that climbs into vegetation outcompeting native species and altering ecosystems in the southeastern United States. The biological control agent, Lilioceris cheni Gressitt and Kimoto (Coleoptera: Chrysomelidae), has been released in Florida since 2011 and in other states including Georgia (2015), Louisiana (2016), Texas (2017), Mississippi (2018), and Alabama (2018) to manage air potato. Despite the wide distribution of the weed and mass rearing efforts, there are no studies documenting the establishment of L. cheni outside of Florida. The objectives of this study were to document the beetle release efforts by several agencies and determine the establishment and impact of L. cheni across the southeastern United States. Using citizen science reports and field surveys, we documented the distribution of the air potato and L. cheni. Results demonstrated that the distribution of air potato extends to temperate regions from SC and GA, to subtropical regions of LA, TX, and FL. Surveys showed that the beetle is established across the release sites and densities fluctuated between 6 to 37 beetles per 30-surveyor-minutes. Most sites sampled had moderate to high beetle damage (scales of 3-4), and air potato cover was low (2-3 scale). However, air potato was still abundant in some areas, which suggests the need for additional beetle releases and/or other tactics necessary to achieve acceptable management.