Modeling the Impact of an Exotic Invasive on Community Structure: Predation on Lepidopteran Larvae By the European Paper Wasp, Polistes Dominulus, in Eastern Massachusetts.
Corey, Tyler B.
- Abstract: The spread of exotic invasive species is an increasing threat to biodiversity and ecosystem functioning worldwide. Exotic invasives negatively impact community structure, although the degree to which they do this is poorly understood for recent introductions. It is therefore essential to elucidate the role that invaders play in new ecological communities. Ecological modeling can be used ... read moreto form testable predictions of the impact of exotic invasives. The European paper wasp, Polistes dominulus, was first found in Eastern Massachusetts in the mid 1970s, and has since established populations across the United States. P. dominulus and its native congener, P. fuscatus, primarily rear brood on lepidopteran larvae, putting the two wasp species in competition and their shared prey species under increased predation pressure. We constructed an individual-based model of wasp foraging and nesting behavior to predict the impact of P. dominulus predation on lepidopteran prey populations. Our model uses location-specific weather data and local demographic data on P. dominulus nest growth, along with published data on foraging and nest building in Polistes wasps, to make targeted predictions of the number of lepidopteran larvae killed by individual P. dominulus nests in invaded communities. Fitting a linear regression model to our model output provided us with an equation that can be used to estimate the amount of caterpillar prey consumed by P. dominulus nests in Eastern Massachusetts. These predictions can be combined with information on P. dominulus nest density and prey preference to better identify how much prey is being consumed in a given area, and which prey species are most at risk from invasive wasp predation. Ultimately, our model serves as a foundation upon which we will continue to build a more generalizable model to predict the impact of paper wasp predation on community structure across the global range of Polistes.read less