Date of Award

5-2025

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

College/School

College of Science and Mathematics

Department/Program

Earth and Environmental Studies

Thesis Sponsor/Dissertation Chair/Project Chair

Matthew L. Aardema

Committee Member

Scott L. Kight

Committee Member

Robert W. Meredith

Committee Member

Dina M. Fonseca

Abstract

Temperature plays a critical role in mosquito life cycle, behavior, and other ecological interactions. My dissertation analyzed how temperature affects egg hatch rates of the eastern treehole mosquito (Aedes triseriatus) and how amino acid substitutions in TRPA1 correlated with host finding through thermotaxis and the convergent evolution of vertebrate feeding/utilizing in Dipterans. As ectotherms, embryonic development and egg hatch rates are directly influenced by the water temperature mosquito eggs are oviposited into. Ae. triseriatus eggs do not hatch all at once, to avoid potentially high larval mortality rates due to their non-static oviposition sites. They engage in staggered egg hatching, with a portion hatching after the eggs go through a series of drying and inundation. The results of my first chapter showed water temperature had a positive effect on the quantity of eggs that hatched in each round. When I compared egg hatch rates in two experimental treatments (20°C, 28°C) more eggs hatched in the first three rounds at 28°C than at 20°C. Additionally, at 20°C egg hatch rates were more uniform throughout rounds. Temperature also influences host finding behavior in Ae. triseriatus and other Dipterans. Discerning between host body temperature and environmental temperature is crucial for flies that require a blood meal or an endotherm to use as an oviposition site. TRPA1 is a gene correlated to host finding via thermotaxis in mosquitoes. In chapter three, I analyzed amino acid substitution differences in a specific region of the TRPA1 gene between vertebrate utilizing and non-vertebrate utilizing flies. I compared 103 fly families, 9 of which contained vertebrate utilizing species. Within family Culicidae I had a novel genome of Ae. triseriatus sequenced (results in chapter two) so that I could access its TRPA1 sequence. There were several positions of note, some with parallel substitutions found only in vertebrate utilizers.

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