UC San Diego

Species introductions dramatically alter the diversity and abundance of native species via competitive and predatory interactions that negatively influence native biota. Although invasive species sometimes form mutualisms within their introduced range, the role of mutualistic interactions on species abundance and food web composition is less known. In this study I examined the invasive Argentine ant (Linepithema humile), a species which readily interacts with carbohydrate-producers within its introduced range. This study investigates these (presumably) reciprocally beneficial food-for-protection mutualisms to determine the broader ecological effects of the mutualism on species external to mutualism. Using field experiments and molecular techniques, I quantify the effects of the Argentine ant on food web structure, diversity, and plant reproduction. This study identifies the broader ecological effects of invasion, and provides insight into management strategies that may minimize the ecological impacts of invasive social insects on native biota