D3073: Infestation potential and abundance of invasive and native ambrosia beetles across apple orchards in Michigan

Increasing populations of invasive ambrosia beetles, particularly Xylosandrus germanus and Anisandrus maiche (Coleoptera: Curculionidae), have caused concern to apple growers in the Eastern U.S. Through their broad range of host trees and the targeting of young and stressed trees, newly established orchards can be vulnerable to attack. In this study, we conducted a survey of ambrosia beetle species near 20 commercial apple orchards across Michigan’s lower peninsula. We collected abundance data for ambrosia beetles at the species level using bottle traps baited with ethanol lures and measured infestation potential using ethanol-soaked bolts. We are interested in knowing what factors might make some orchards more susceptible to attack than others. These factors include tree age and cultivar, high vs low density planting systems, environmental variables, and surrounding woodlots and their composition. Using GIS, we plan to look at the topography, soil composition, and proportion of surrounding wetlands to run a multivariate analysis that includes orchard and environmental variables that may impact tree health.