Seasonality and endophytic presence of the entomopathogen, Beauveria bassiana, on Kudzu Bug, Megacopta cribraria, in east Tennessee

When kudzu bug, Megacopta cribraria, was identified in the United States in 2009 as an invasive species, populations began to establish, increase, and spread throughout the southeastern region at intense rates. Kudzu bug invades urban structures, causing unpleasant scenes for homeowners, and reduces crop yield, such as soybean. Kudzu bug caused about $1,000,000 in soybean yield loss and treatment in Tennessee in 2019. Although initial invasion was rapid throughout the southeastern United States, spatial modeling has shown populations of kudzu bug are declining and reducing risk of crop damage to growers. These local and regional declines in populations appear to be influenced by at least two natural enemies, a naturally-occurring entomopathogenic fungus, Beauveria bassiana, and an accidentally introduced egg parasitoid, Ooencyrtus nezarae. O. nezarae causes 52% mortality in kudzu bug eggs and B. bassiana causes about 90% and 33% mortality in second-generation immature kudzu bugs and adult kudzu bugs, respectively. Endophytic presence of B. bassiana in kudzu increases throughout the growing season and, by mid-August, B. bassiana colonizes up to 23% of a kudzu vine. Endophytic colonization and entomopathogenic infection increase with seasonal changes. The establishment and success of these natural enemies to cause mortality of kudzu bug will play an important role in driving population dynamics to maintain population declines in the southeastern United States. The purpose of this presentation is to provide information on the distribution, seasonality and impact of Beauveria bassiana on kudzu bug populations in east Tennessee, with implications for the United States.