Movement and dispersal of cerambycid beetles (Coleoptera: Cerambycidae) in urban forest fragments

Background/Question/Methods

Adult cerambycids locate hosts and mates using aggregation or sex pheromones, many of which have been identified and produced synthetically. The range at which the pheromones attract cerambycids has not been established; our experiment aimed to determine this range. We placed concentric circles of unbaited flight intercept traps around a single baited or unbaited trap in forest fragments in northern Delaware. We collected cerambycids for 13.5 weeks and identified each to species. For each trap, we calculated the total cerambycid catch in each trial. We used a two-way ANOVA with treatment and distance from the center as factors. When these factors were significant, we used a Tukey test to determine which traps caught significantly more cerambycids.

Results/Conclusions

Both treatment and distance from the center were significant factors for total cerambycid catch. Inside forest fragments, center baited traps and those 2 m away contained significantly greater catch. Most individual species followed this trend, with the exception of Prionus laticollis, which is attracted by a sex pheromone and was only caught in large numbers at the center baited trap. We conclude that the range of attraction of the pheromone blend is between 2 and 10 meters, but depends on the specific pheromone and its mechanism of attraction. Future research will aim to better understand cerambycid movement by placing flight intercept traps outside forest fragments at increasing distances from a forest edge. We also plan to analyze the genetic population structure of cerambycids from forest fragments throughout northern Delaware.