Dissertation Research: Ecological Effects of an Invasive Social Wasp on Endemic Hawaiian Arthropods

University Of California-San Diego, La Jolla CA

Investigators

Abstract

The introduction of non-native organisms is a leading cause of species imperilment. Through the study of interactions between native and introduced species, a better understanding of the causes and consequences of invasions may be obtained. This proposed research will examine the underlying mechanisms of a social wasp invasion and identify traits influencing the success of Vespula pensylvanica, the western yellowjacket, through comparative studies in its native range (California) and introduced range (Hawaii). The effect of invasive predators on native species depends upon the history of the recipient community. Because Hawaii lacks native social insects, the introduced western yellowjacket may seriously threaten endemic invertebrates, including herbivores, predators and pollinators. The proposed study uses a combination of classic ecological approaches and modern molecular methods (1) to quantify the effect of an invasive yellowjacket on native prey and competitor taxa, and (2) to assess differences in resource exploitation between V. pensylvanica and native solitary wasps. Preliminary results indicate that prey and competitor abundance decline significantly in the presence of this invasive yellowjacket. In addition, this research investigates the foraging strategies of V. pensylvanica and compares patterns of resource depletion by V. pensylvanica and native solitary wasps. The broader impacts of this study will be (1) to further our understanding of factors contributing to invasion success, and (2) to contribute to the development of effective management strategies that seek to minimize the ecological impacts of invasive social wasps, such as V. pensylvanica.