| This dissertation consists of six independent chapters detailing studies of the chemical ecology of longhorned beetles (Coleoptera: Cerambycidae) in the subfamily Cerambycinae and the tribe Clytini.; In chapter 1, I describe the calling posture of the redheaded ash borer Neoclytus a. acuminatus. I demonstrated that pheromone was produced only from the prothorax of males and only when males were in the calling posture (a.k.a. the push-up stance).; In chapter 2, I used mark-and-recapture techniques to test the predictions that a trapping regime using the aggregation pheromone of N. a. acuminatus can lower numbers of adults in a landscape and that trapping with the pheromone has potential as part of an integrated control strategy for this species. Almost 43% of marked beetles were recaptured over six replicates of the study and the study suggests that trapping caused dramatic declines in population levels.; In chapters 3, 4, and 5, I test the hypothesis that a structural motif of aggregation pheromones produced by males of cerambycine species, consisting of molecules that are six to ten carbons in length (usually six carbons) with hydroxyl or carbonyl groups at C2 and C3 is conserved in many species. Odors collected from male Neoclytus m. mucronatus contained one major male-specific compound, identified as (3 R)-3-hydroxyhexan-2-one. Odors collected from male Xylotrechus colonus (F.) and Sarosesthes fulminans (F.) also contain this compound in addition to other structurally related pheromone components. These three species show apparent cross-attraction to the pheromone components. In contrast, the species Megacyllene caryae produce two compounds that conform to the motif and also produce an array of alcohols and terpenoids unprecedented in the Cerambycinae. In field bioassays, M. caryae was optimally attracted to a blend of all eight compounds identified from the species.; In chapter six, I characterize the contact sex pheromone of N. a. acuminatus. Males recognize female conspecifics only after contacting them with their antennae. I characterize the behavior and demonstrate that three methylalkanes present in the wax layer of females are sufficient to elicit a mating response from males. |
