An Ecological Study of the Kudzu Bug in East Tennessee: Life History, Seasonality, and Phenology

The kudzu bug, Megacopta cribraria (Hemiptera: Plataspidae), an invasive species from Asia, was first discovered in the United States in 2009 in Georgia. It has since spread to other states, including Tennessee, where it has spread rapidly to numerous counties in four years. Its common name, kudzu bug, implies a potential benefit to management of the invasive species kudzu; unfortunately, the kudzu bug has shown little impact on reducing growth of kudzu. The kudzu bug causes agricultural, urban, and health-related concerns in the United States. Soybean losses by kudzu bug have exceeded 20% in some areas of the southeastern United States.

Primary research goals of this project are to: 1) assess ecology of kudzu bug in Tennessee; 2) determine behavioral responses of kudzu bug to host substrates; and 3) examine the relationship between kudzu bug and natural enemies present in Tennessee. In 2014 and 2015, studies were conducted to better understand population dynamics of kudzu bug in Tennessee. Kudzu bugs were present on kudzu in Knox County until early November in 2014 and mid-May to late November in 2015, with mid- and late-season peaks both years. Kudzu bugs were present at sites in other counties throughout the same time. Kudzu bugs exhibited different population trends in all counties, possibly due to differences in latitude, agricultural practices, and topography.

In laboratory studies, kudzu bugs were more active on kudzu than alternate host plants (soybean, bush honeysuckle, and ragweed). Ragweed was the least attractive plant species. In no-choice tests, activity was similar across kudzu, soybean, and bush honeysuckle. In choice tests, kudzu had the highest percent of active insects.

An unexpected natural enemy was found at all regularly sampled sites in 2015. Beauveria bassiana, an entomopathogenic fungus, was discovered infecting kudzu bug and impacting population densities. Mortality of immature kudzu bugs reached 100%. The kudzu bug egg parasitoid, Paratelenomus saccharalis, was not recovered.

The outcome of this research project will provide essential information on ecology of kudzu bug in Tennessee. This information will help to enhance development and implementation of efficient and effective management tools.