The role of host volatiles combined with pheromones in the chemical ecology of cerambycid beetles

It has been hypothesized that some species of cerambycids will not be attracted to pheromones alone, but require a blend of host volatiles with pheromones as an effective attractant. To test this hypothesis, Fluon-treated intercept panel traps were baited with a blend of pheromones, or a blend of pheromones plus chipped wood and foliage from host trees. Traps were deployed in Southern California in two different habitats, the San Bernardino National Forest and the Irvine Ranch Water District. The chipped host material was from one of several local conifer or hardwood tree species, and the pheromones were a blend of six previously identified cerambycid pheromones. Chipped material was refreshed weekly, and chips from different host species were cycled through the array of traps every two weeks. The trap catch data will be reviewed to try and identify trends in species which respond strongly to pheromones alone, versus species that only respond to or respond much more strongly to blends of pheromones with host odors. Overall, our goal is to identify host volatiles for use in developing better attractants for cerambycid species.