Semester of Graduation

Spring 2025

Degree

Master of Science (MS)

Department

Biological Sciences

Document Type

Thesis

Abstract

Climate change may alter host-pathogen dynamics in terrestrial ecosystems due to rising global temperatures and carbon dioxide levels. Here, we examined cannibalism and disease transmission using the fall armyworm (Spodoptera frugiperda), an invasive agricultural pest, and its species-specific lethal baculovirus, Spodoptera frugiperda multiple nucleopolyhedrovirus (SfMNPV), under various potential challenges of climate change. We used three temperature treatments (cooler, optimal, warmer) based on the fall armyworm’s thermal performance curve to simulate a changing climate and four artificial diets with various protein-to-carbohydrate ratios (low, equal, high, standard) to manipulate resource quality from altered carbon dioxide levels. We found that higher temperatures increased cannibalism in larvae on all resource types. Larvae cannibalized more when provided with a lower protein diet. Warmer temperatures led to slightly higher disease transmission of SfMNPV, though diet type did not influence infection results in cannibals. Changes in global temperatures and carbon dioxide levels could cause more frequent cannibalism in the fall armyworm and similar species, though disease transmission from cannibalism alone may not increase substantially. We also found significant differences in fitness estimates between each temperature and diet treatment; individuals fed more carbohydrates (lower protein) and kept at cooler temperatures had larger pupal masses, indicating potentially higher fitness, while individuals fed more protein and kept at warmer temperatures had lower fitness potential.

Date

4-22-2025

Committee Chair

Elderd, Bret D.

Available for download on Wednesday, April 22, 2026

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