Date of Award

Fall 12-2015

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Biological Sciences

Committee Chair

Donald Yee

Committee Chair Department

Biological Sciences

Committee Member 2

Jake Schaefer

Committee Member 2 Department

Biological Sciences

Committee Member 3

Carl Qualls

Committee Member 3 Department

Biological Sciences

Committee Member 4

Frank Moore

Committee Member 4 Department

Biological Sciences

Committee Member 5

Barry Alto

Abstract

A challenge faced by organisms with complex life cycles is how environmental factors experienced at an earlier life stage affect the fitness at that stage or are carried over to subsequent life stages. I used container-inhabiting mosquitoes: Aedes albopictus, Aedes aegypti, Aedes triseriatus and Culex quinquefasciatus to study the interactions and performance of life history stages under specific environmental factors. I investigated the effects of egg-desiccation tolerance on egg viability and larval performance in the Aedes mosquitoes. I found increase in egg hatch rate with relative humidity and interaction between relative humidity and egg storage period. Larval performance differed among species, but egg-desiccation tolerance did not lead to higher larval performance. I examined the effects of temperature on the outcome of larval intraspecific competition as well as interactions between temperatures for rearing and those for adult maintenance in Aedes albopictus. I found that increasing temperatures resulted in shorter development time and smaller adult sizes while increasing densities led to longer development time and smaller adult sizes for males and females. There was also an interaction between larval and adult temperatures; higher temperatures led to greater differences in female fecundity, and lower temperatures led to increased survival. I investigated the effects of female natal habitat on oviposition responses and larval performance in Ae. albopictus, Ae aegypti and Cx quinquefasciatus. I found that Ae aegypti showed no oviposition preference, Ae. albopictus significantly preferred animal:leaf detritus infusion and Cx quinquefasciatus did not oviposit in tap water. However, there were no overall carry-over effects of natal habitat on oviposition choices and population growth. I examined the relationships among female natal habitat, female size, egg number, and egg volume in Ae. albopictus and Cx. quinquefasciatus. For Ae. albopictus, I found strong positive relationships in animal detritus with female size and egg number, and in leaf detritus with egg volume. For Cx. quinquefasciatus, I found strong positive relationships in animal detritus with female size and egg number. My study provides more insight on the importance of habitat heterogeneity and environmental stochasticity, and the strength of their carry-over effects across life stages in complex life cycles.

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