090. Bugs Are Picky and Wildflowers Don't Share

Presenter(s)

Jackson Turner

Abstract or Description

Jackson Turner, Jessica Moore, Stephanie Kivlin Department of Ecology and Evolutionary Biology, University of Tennessee, 569 Dabney Hall, 1416 Circle Drive, Knoxville, TN 37996, USA - Insect herbivores contribute to ecosystem productivity by removing plant biomass and as a food source for other organisms within their ecosystems. Native wildflowers that form close associations with native insects are useful for examining dynamics of insect herbivore communities over time. Insect diversity in these systems is important because different orders may fill different ecological niches and contribute differently to ecosystem productivity. Understanding how the community composition of these insect herbivores among wildflower species changes over time allows us to make informed decisions regarding the maintenance of insect biodiversity.  To test this, I sampled insects from 10 individuals each of four different wildflower species at the Oak Ridge National Laboratory west campus over eight weeks starting in early June 2019. Each week, I identified insects on individual study plants (N=40) to order and recorded environmental and plant metrics: temperature, cloud cover, precipitation, plant height, total number of leaves per individual, and (percent? proportion?) leaves exhibiting herbivore damage. To understand how the abundance and diversity of these insect herbivore orders changed through time, I used a linear mixed model and distance-based redundancy analysis to examine differences in insect herbivore community structure between wildflower species. Abundances and diversities of insect herbivore orders varied nonlinearly through time, with a peak in both at week 7. Insect herbivore abundance and diversity varied among all wildflower species and over time. Insect herbivore community abundance and diversity changed over time for all wildflower species. Differences among wildflower species in herbivore communities were driven by goldenrod (Solidago canadensis/altissima), with no other wildflower species having significantly different community structures from one another. These results suggest that insect herbivore communities fluctuate across the growing season as the abundances of different insects fluctuate both with their associated wildflowers and the niches they inhabit within their ecosystems.