Factors affecting catches of bark beetles and woodboring beetles in traps

The use of semiochemical-baited traps for detection, monitoring, and sampling bark beetles and woodboring beetles (BBWB) has rapidly increased since the early 2000s. Semiochemical-baited survey traps are used in generic (broad community level) and specific (targeted toward a species or group) surveys to detect nonnative and potentially invasive BBWB, monitor established populations of invasive or damaging native species, and as a tool to survey natural communities for various purposes. Along with expansion in use, much research on ways to improve the efficacy of trapping surveys for the detection of specific pests as well as BBWB in general has been conducted. In this review, we provide information on intrinsic and extrinsic factors and how they influence the efficacy of detecting BBWB in traps. Intrinsic factors, such as trap type and color, and other factors are described, as well as important extrinsic factors such as habitat selection, horizontal and vertical placement, and disturbance. When developing surveys, consideration of these factors should increase the species richness and/or abundance of BBWB captured in traps and increase the probability of detecting nonnative species that may be present. During generic surveys, deploying more than one trap type or color, using an array of lures, and trapping at different vertical and horizontal positions is beneficial and can increase the number of species captured. Specific surveys generally rely on predetermined protocols that provide recommendations on trap type, color, lure, and trap placement.