Archived

This content is available here for research, reference, and/or recordkeeping.

Author ORCID Identifier

https://orcid.org/0009-0003-7647-8254

Date Available

4-30-2026

Year of Publication

2026

Document Type

Master's Thesis

Degree Name

Master of Science (MS)

College

Agriculture

Department/School/Program

Entomology

Faculty

Jen White

Faculty

Charles Fox

Abstract

Maternally inherited bacterial endosymbionts are common in arthropods. Many of these bacteria manipulate host reproduction to favor the production of infected females, thereby increasing bacterial prevalence in the host population, even if cost is incurred to the host. However, there are also many factors that may inhibit symbionts’ ability to spread in host populations, including environmental constraints, symbiont-imposed costs on the host, interactions with co-infecting bacteria, or host biology. I explored two aspects of symbiont biology within a spider host, Mermessus fradeorum (Linyphiidae), which has varying combinations of up to five different bacterial endosymbionts in local populations: Rickettsiella, Tisiphia, and three strains of Wolbachia. This system has two forms of reproductive manipulation: The Rickettsiella bacteria causes cytoplasmic incompatibility (CI), and one Wolbachia strain, “Wolbachia 1”, causes feminization. My first goal was to examine whether greater symbiont diversity lowered host fitness in terms of female fecundity and host survival. I found that fitness was lower only in individuals who possessed the feminizing Wolbachia 1, which I hypothesize is due to the host’s XX/X0 type of sex determination system. My second goal was to determine temperature effects on CI. I found that increased temperature decreased male capability to induce CI and marginally decreased female capability to rescue CI. The temperature effect on induction does not appear to be mediated through host development rate. This thesis shows that some aspects of symbionts and their interactions are context dependent while others are not. Interactions between the environment, hosts, and symbionts are important in understanding and predicting symbiont persistence in natural populations and application to other arthropod endosymbiont systems such as pest and vector management.

Digital Object Identifier (DOI)

https://doi.org/10.13023/etd.2026.230

Archival?

Archival

Funding Information

This material is based on work supported by the National Science Foundation (1953223) and the National Institute of Food and Agriculture, U.S. Department of Agriculture (Hatch Nos. 1020740, 7007679). 2021-2026.

Download

Share

COinS