Date of Award
2024
Document Type
Thesis
Degree Name
Bachelor of Science
Department
Biology
First Advisor
Dr. Priscilla Erickson
Abstract
Understanding the mechanisms underlying the success of biological invasions is essential to employ effective prediction and management strategies. The release of natural enemies in invaded regions (enemy release hypothesis) and increased competitive ability are major hallmarks of invasive species, however, these two processes are rarely studied within the same context. Here, we examined the role of ERH in influencing the competitive outcomes of an invasive insect pest, the African fig fly (Zaprionus indianus). In Virginia orchards, Z. indianus repeatedly outcompetes co-occurring drosophilid species. However, the mechanisms underlying the success of Z. indianus are poorly understood. Parasitoid wasps specializing in Camill Ut drosophilid larvae may seek out established species with known host suitability over a novel species with unknown host suitability. Therefore, Z. indianus may have low susceptibility to parasitoid wasps, mediating their competitive success in Virginia orchards. This hypothesis was tested by comparing the emergence rates of Z. indianus in intra- and interspecific competition assays in the absence and presence of the parasitoid wasp Leptopilina heterotoma. Intraspecific competition assays revealed that Z. indianus emergence rates were significantly decreased in the presence of wasps, suggesting that they are susceptible to parasitization by L. heterotoma. In interspecific competition assays in the presence of wasps, Z. indianus emergence rates were not significantly different from the emergence rates of Drosophila simulans at low or high densities, nor from D. hydei at low densities. However, Z. indianus emerged at significantly higher rates than D. hydei at high densities in the presence of wasps. These results suggest that Z. indianus exhibits wasp susceptibility similar to other drosophilid species at low densities, but may be variable at high densities. Verifying these results in field environments could provide vital insight into potential forms of biocontrol management for Z. indianus.
Recommended Citation
Walsh-Antzak, Camille, "The effects of parasitoid wasps on the intra- and interspecific competition of Zaprionus indianus" (2024). Honors Theses. 1784.
https://scholarship.richmond.edu/honors-theses/1784