Date of Award

2022-12-01

Degree Name

Doctor of Philosophy

Department

Biological Sciences

Advisor(s)

Douglas M. Watts

Abstract

Aedes aegypti is a medically important mosquito species that transmits multiple arboviruses, including dengue, chikungunya, Zika, and yellow fever. This mosquito species has expanded its geographical range into expanded into the Northern Chihuahuan Desert to further increase the risk of infection by these viruses in naïve human populations. Although Ae. aegypti is abundant along the U.S.â??Mexico border, the biology and ecology of this mosquito species in this temperate/arid climate region is not understood. The objective of this study was to understand the environmental factors that influence the invasive species of Ae. aegypti abundance, breeding habitat selection, host feeding behavior, and population structure in two unincorporated urban communities, including Sparks, Texas and Anapra, Ciudad Juarez, Chihuahua, Mexico. Ae. aegypti were collected at various life stages from 2016â??2018. A total of 209 families participated in this binational study, including 108 families in Sparks and 101 in Anapra. Ae. aegypti populations in both Sparks and Anapra were influenced by environmental and climatic factors. In Sparks, drier months of June and July had a 3-year average of 81 Ae. aegypti captured, which was followed by peak density from August to October with a 3-year average of 888 Ae. aegypti captured and was followed by the decrease until absence until absence in November and December. In Anapra, June to July had a 3-year average of 44 captured Ae. aegypti, which was immediately followed by peak density from August to October with an average of 270 Ae. aegypti captured, then complete absence occurred in December. In Sparks, a total of 601 Ae. aegypti larvae were collected and raised to adults from 24 contains; in Anapra only 7 containers produced 68 adult Ae. aegypti. The container type that produced the most larvae were plastic buckets in both communities. The blood meal was identified from 17 of the 44 (17 in Sparks & 27 in Anapra) fully blood engorged females. In the Sparks community, the results indicated that 4 Ae. aegypti had fed on dogs, 1 had fed on a human, 1 had fed on a chicken. In the Anapra community the results indicated 8 had fed on humans, 2 had fed on dogs, and 1 had fed on a cat. The population structure analysis with PCA and ADMIXTURE, identified four major collection locations (Sparks, Anapra, and two areas in the city of El Paso: El Paso B and El Paso E) and eight functional genes under selection pressure across for of six putative outlier loci. Only three of the eight genes had known functions: 1) a TATA box binding protein; 2) a calmodulin protein involved in olfactory; 3) a protein in the superfamily of C-type lectins. The findings generated by this first longitudinal binational study in the Northern Chihuahuan Desert provided insight to the population dynamics, breeding site preference, host feeding behavior and genetic structure of Ae. aegypti. All of these are crucial to understanding the biology and ecology of this medically important mosquito species to adapt to establish in a temperate/arid climate.

Language

en

Provenance

Received from ProQuest

File Size

123 p.

File Format

application/pdf

Rights Holder

Adam Joseph Vera

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