BRC-BIO Assessment of character displacement in cooperatively nesting wasps

About This Grant

Social wasps are ecologically and economically important species that benefit humans and ecosystems by eating pest insects, pollinating flowers, and serving as a food source for birds and mammals. Despite the global impact of social wasps, we have a poor understanding of what causes diversification in this group and what mechanisms allow multiple similar species of wasp to co-occur in the same habitat. This project will investigate if character displacement – an evolutionary process through which overlapping species reduce competition by evolving to use alternative resources – has helped drive speciation in social wasps. This knowledge gap is particularly critical because many ecosystems are currently experiencing declines in the biodiversity and abundance of insects. Simultaneously, globalization and anthropogenic change have led to recent expansions of the range sizes of native wasp species as well as an increase in the number of invasive wasp populations worldwide. Improving our understanding of resource partitioning in social wasps is crucial for predicting how future changes in social wasp abundance and distribution will impact local ecosystems. The project will provide opportunities for University of Missouri – St. Louis undergraduate students to participate in impactful scientific research by creating 9 paid undergraduate research positions, and by integrating research activities into a course based undergraduate research experience (CURE) lab for 24 students. The Polistes paper wasps are an ideal group for investigating these questions as these colorful species all occupy the same broad ecological niche, and as many as ten species can co-occur within a region. This project will examine character displacement in either ecological resource use or in the signals or cues used for species recognition at three different scales. First, a large, global, phenotypic dataset will be used to determine if variation in body color patterning of Polistes species is consistent with character displacement or other ecological processes. Next, field collections will be made in regions with low, medium, and high species diversity in the United States to test whether phenotypic distribution changes with wasp community composition. Lastly, this project will experimentally test if wasps use body coloration to discriminate between species. Combined, data generated by this project will increase our limited understanding of the role of character displacement in maintaining insect species. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.