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

Air potato, Dioscorea bulbifera L. (Dioscoreaceae), is an invasive vine that climbs into vegetation outcompeting native species and altering ecosystems in the southeastern USA. 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 USA. Using community science reports and field surveys, we documented the distribution of air potato and L. cheni. Results demonstrated that the distribution of air potato extends to temperate regions from South Carolina and Georgia to subtropical regions of Louisiana, Texas, and Florida. Surveys showed that the beetle is present across all states with releases, and numbers fluctuated between 6 and 37 beetles counted per 30-surveyor-minutes. Most sites sampled had moderate to high beetle damage (scales of 3–4 out of 5), and air potato cover was low to moderate (2–3 out of 5). However, air potato was still abundant in some areas, which suggests the need for additional beetle releases and/or the use of other tactics to achieve management goals. [ABSTRACT FROM AUTHOR]