Role of host plant volatiles and female produced sex pheromone in the mating system of Mallodon dasystomus (Say)(Coleoptera:Cerambycidae)

In the literature review, I discuss the environmental and economic importance of longhorned beetles and detail the use of semiochemicals in their mating systems. Cerambycids employ three host and mate location strategies to unite the sexes: a mutual response of males and females to host plant volatiles; male-produced aggregation pheromones; and female-produced sex pheromones. The review concludes with a discussion of natural enemies of longhorned beetles. In Chapter 1, I explore the mate location behavior of M. dasystomus and test the hypotheses that the sexes are mutually attracted to volatiles emanating from the larval host and that females release a volatile pheromone that is attractive to males alone. In a Y-tube olfactometer, male and female M. dasystomus responded to volatiles from host material (i.e., sweetgum and sugarberry). However, only males responded to females in the olfactometer, suggesting that females release a volatile sex pheromone. Choice tests performed in a greenhouse also revealed that males and females are attracted to logs of known host plants over non-host material. In further bioassays in a greenhouse, males also responded significantly to host material containing a live female. These findings are evidence of the critical role host volatiles and pheromones play in mating systems of longhorned beetles. In Chapter 2, I test the hypothesis that volatile pheromone components of longhorned beetles may serve as generic lures to attract a variety of species within the family. I set three transects, each with 11 panel traps spaced 10 meters apart. Two transects were set at the USDA Delta Experimental Forest, Washington Co., Mississippi. The third transect was set at Delta National Forest, Sharkey Co., Mississippi. I collected a total of 1042 specimens representing 35 species of longhorned beetles. There was a greater treatment effect of some species than others, indicating that the compound may be an important pheromone component of that species. This information provides further evidence that pheromone structures may be conserved within subfamilies, and may help expedite identification of cerambycid pheromones. Individual components of cerambycid pheromones from four subfamilies (Cerambycinae, Lamiinae, Prioninae and Spondylidinae) may be used as generic lures to attract a variety of longhorn species within these subfamilies