D3075: Assessing the impacts of bottom-up effect on larval development and reproductive ecology of two species of longhorn beetles

Bottom-up effects are the predominant drivers of community structure, function, and population dynamics of herbivorous insects in many ecosystems, including managed and unmanaged forests. Plants can mediate the bottom-up effects that alter host suitability for herbivores, impacting larval survival, development, longevity, and the reproductive fitness of adult insects. We will evaluate how bottom-up effects impact the natural history of two abundant, polyphagous longhorned beetles (Cerambycidae), Neoclytus acuminatus and Xylotrechus colonus. Longhorned beetles are an ecologically and economically important group of insects that are readily moved globally in wood and wood packing materials associated with trade. It is not well known how feeding in different hosts may impact the population dynamics and success of longhorned beetles in their native or introduced ranges.

Because plant often differ in their primary and secondary chemistry, we hypothesized that larval development and adult reproductive traits will differ for longhorned beetles feeding in different host plants. Using beetles from a laboratory colony on a shared host plant (Carpinus caroliniana), we will inoculate fifteen replicates of three host plants of each longhorn beetle (N = 90 logs) with 4 longhorned beetle eggs. The effect of host on larval development time and reproductive traits such as body size, fecundity, and pheromone emission will be analyzed with mixed models. Consequently, the findings of this study will help to predict how changes in the forest structure and composition impact the abundance, distribution, and population dynamics of woodborers of concern, such as those that are endangered or invasive.