Using multicriteria risk models to guide non-destructive surveys for emerald ash borer

The emerald ash borer (Agrilus planipennis, EAB) is an exotic wood boring beetle from Asia that has become a major pest of ash trees (Fraxinus spp.) in parts of North America. Naturally EAB adults can fly only one mile, however the insect has been spread throughout the Midwest aided by humans through the movement of firewood, nursery stock, and other wood materials containing larvae, pupae and adults. Known locations of emerald ash borer were used to develop a multicriteria risk model that uses geographic information system data to determine areas at highest risk for EAB. The model incorporates land cover, proximity to roads, and proximity to campgrounds as factors affecting spread of the insect. Using the predicted risks a ground survey identifying signs and symptoms of infestation was conducted in summer 2009 focusing on high risk areas. This method of detection allows for an increased number of survey sites over a large area and is non-destructive in that it does not use girdled trap trees or hanging traps.