Role of semiochemicals in the host colonization behavior of the peach bark beetle, Phloeotribus liminaris (Harris)

Black cherry (Prunus serotina) is among the most marketable hardwoods in North America. Unfortunately, widespread infestations of the peach bark beetle, Phloeotribus liminaris (Harris), keep many of these trees from reaching veneer quality and significantly reduce their value. Nevertheless, the host colonization and mating behavior of this beetle is poorly understood. In this study, we test the hypothesis that osmotic stress influences the susceptibility of black cherry to colonization by the peach bark beetle. In a greenhouse, two year old cherry saplings were osmotically stressed as indicated by leaf water potential to three levels; control °Ü -0.6 megapascals (mPa), medium -0.6- (-1.2) mPa, and high °Ý -1.2 mPa. In a no-choice experiment, fifteen beetles of each sex were caged on approximately 50cm2 of the main stem of each tree and allowed to colonize for two weeks. After two weeks, we recorded and sexed those beetles recovered within the cages, trees and resinous pitch. We also quantified the feeding wounds in the bark of each tree. We found that osmotic stress did not significantly influence susceptibility of the saplings to colonization, suggesting the beetles are capable of infesting vigorous trees. Moreover, in olfactometer bioassays, we found that both males and females are attracted to volatiles emanating from black cherry, suggesting that host kairomones mediate host location. Information on the colonization behavior of peach bark beetle will aid in establishing effective management programs, such as improving detection methods and optimizing survey strategies.