Optimizing the Efficiency of Monitoring for the Emerald Ash Borer (Agrilus planipennis) in Maine by Understanding the Behavior of Cerceris fumipennis and its application in Biosurveillance

Invasive species impact the composition of the forests of the United States as well as our urban and suburban treed landscapes. One such insect is the emerald ash borer (Agrilus planipennis; EAB). Native to eastern Asia, EAB made it to the United States in wood packing materials used in shipping. First discovered in 2002 in Michigan by the USDA, EAB has since spread to 15 U.S States and two Canadian Provinces (Haack et al. 2002, Cooperative Emerald Ash Borer Project 2012). Although it has not yet been detected in Maine, its arrival is expected. An effective monitoring technique for the detection of this invasive insect involves the use of a native, ground-nesting wasp, Cerceris fumipennis, which provisions its young with adult Buprestidae. Programs are being implemented in several states, including Maine, using C. fumipennis for biosurveillance of EAB. The aim of this study is to examine the impact of local abiotic conditions and native prey species on wasp foraging activity and probability of detecting EAB. In July and August of 2010 and 2011, five wasp aggregation sites were monitored in central Maine. Air temperature, soil surface temperature, solar radiation, humidity, barometric pressure, and wind speed were recorded and coupled with observations of the number of wasps seen flying and the number seen returning with prey at a given time. In 2010 and 2011 prey items were taken from wasps by sweep-netting females carrying prey or as discarded beetles within aggregations. Data were analyzed using stepwise multiple or logistic regression. Prey items collected were identified to species. Trends between wasp flight activity and site, Julian day, air temperature, wind speed, humidity, barometric pressure, and solar radiation were observed. It is our recommendation that to maximize the efficacy of biosurveillance programs for the EAB in Maine that all who conduct biosurveillance be sent to observe wasps between noon and 2:00 PM, at temperatures between 25°C and 30°C, with wind speeds below 6 Kt, relative to when the greatest number of wasps will be active