The effects of pale swallowwort (Vincetoxicum rossicum) on forest moth communities

Abstract

Pale swallowwort (Vincetoxicum rossicum) is an invasive vine that is rapidly invading northeastern forested ecosystems. Due to its broad tolerance of abiotic conditions and competitive advantage, it is perceived as a threat to native plant communities. Our study sought to determine whether or not invasion by pale swallowwort had a pronounced impact on moth (Lepidoptera) communities. We surveyed three pairs of deciduous forest plots and three pairs of coniferous forest plots. Each pair had a swallowwort plot and a plot without swallowwort. We used light traps to collect a total of 2,039 moths from 19 families and assessed differences in mean abundance, richness, and diversity. We found no differences in moth communities between canopy types or swallowwort plot types. We also assessed differences in abundance of four taxa (Halysidota tessellaris, Idia aemula, Malacosoma americana, and Noctua pronuba), which were all more abundant in deciduous canopy plots. This suggests that the scale of an invasion and the quality of habitat invaded are both important factors to note when trying to quantitatively assess their impacts on higher trophic levels.