USF St. Petersburg campus Master's Theses (Graduate)

First Advisor

Major Professor: Melanie Riedinger-Whitmore, Ph.D.

Second Advisor

Deby Cassill, Ph.D.

Third Advisor

Alison Gainsbury, Ph.D.


University of South Florida St. Petersburg

Document Type


Publication Date


Date Issued

March 27, 2020


Insect galls are a common feature in many xeric environments, where hiding away inside a plant host offers developing larvae consistent food and shelter from harsh conditions. This study aimed to identify the most significant environmental factors that affect local populations of oak-galling wasps (Hymenoptera: Cynipidae) associated with three Quercus species found in xeric habitats located in southwest Florida, USA. Cynipid gall diversity, richness, and abundance were quantified for 35 sample sites across 11 counties, counting only winter-season galls. All sample sites were located within xeric, fire-managed, vegetative communities. It was hypothesized that time since last fire, habitat size, latitude, and tree size would have significant and positive correlations with cynipid Shannon-Weiner diversity (H’), species richness, and gall abundance per site. It was also hypothesized that individual host Quercus species and Quercus species richness would influence cynipid populations. A total of 4,305 individual galls from 21 cynipid species were counted. Time since fire was the strongest predictor tested in this study, significantly correlating with both cynipid diversity and richness. It was also a predictor of mean tree height, which was the only predictor found for gall abundance. Leaving unburned refugia within fire-managed areas should therefore be considered an important management tool for the protection of galling insect diversity. Individual Quercus species and Quercus richness also affected local cynipid assemblages, but played more minor roles in community-level metrics than time since fire.


A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Conservation Biology Department of Biological Sciences College of Arts and Sciences University of South Florida St. Petersburg

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.