Chemically-mediated host colonization and mating behavior of bark and ambrosia beetles (Coleoptera: Curculionidae: Scolytinae) affecting native hardwoods

Nicole R VanDerLaan, Purdue University

Abstract

In Chapter 1, I review the literature regarding the semiochemistry of bark and ambrosia beetles affecting native hardwood trees. I describe the host colonization behavior of bark and ambrosia beetles and discuss the role semiochemicals play in locating suitable hosts. Additionally, I briefly describe the natural enemies of scolytid beetles affecting hardwoods. In Chapter 2, I evaluate the response of two exotic invasive ambrosia beetles, Xylosandrus crassiusculus and X. germanus, to conophthorin, a common bark volatile of deciduous trees in mixed-hardwood forests in north central Indiana and determine the extent to which conophthorin enhances the attraction of these ambrosia beetles to ethanol-baited traps. I test the efficacy of verbenone alone as a repellent of these ambrosia beetles. Exotic invasive ambrosia beetles are among the most economically important pests of trees in nursery stock and managed and natural forest systems in the United States. I found that conophthorin enhances the response of X. crassiusculus and two checkered beetle predators, Madoniella dislocatus and Pyticeroides laticornis, to ethanol-baited traps. There were fewer X. germanus and X. crassiusculus beetles within the verbenone-baited traps, suggesting it acts as a repellent for these beetles. The use of a non-host semiochemical repellent, such as verbenone, in combination with an attractant, conophthorin and ethanol, could be used to deter unwanted infestations of already established ambrosia beetles from marketable trees in a push-pull strategy. In Chapter 3, I test the hypothesis that the host colonization behavior of Phloeotribus liminaris, an important pest of black cherry, is chemically mediated. Black cherry (Prunus serotina) is among the most marketable hardwood species 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 the value. These beetles spend the majority of their life cycle concealed beneath the bark of trees, making them difficult to control with sprayed pesticides. To determine if the beetles are attracted to volatiles emanating from the larval host, we measured their walking response to bolts of black cherry in a glass olfactometer. We tested the attraction of adults to bolts infested with either males or females to determine whether a volatile pheromone mediates colonization behavior. In the field, we measured the response of beetles to baited Lindgren funnel traps. In these assays, males and females were significantly attracted to female-infested bolts, suggesting the presence of a female-produced aggregation pheromone. Information on the chemically-mediated colonization behavior of the peach bark beetle will aid in establishing effective management programs.

Degree

M.S.

Advisors

Ginzel, Purdue University.

Subject Area

Forestry

COinS