Correlation between Tergite Scaling and Desiccation Resistance in Aedes Aegypti

Abstract

Aedes aegypti is a globally invasive species of mosquito. A principal vector of illness including yellow fever, dengue, chikungunya, and Zika, and one of very few species of biting insect that shows an active preference for human hosts, A. aegypti has been a species of interest for scientists in many different fields for over a century. Unusually, this preference for a human host can be predicted by morphological characteristics. Adult A. aegypti individuals show a gradient in body color, from brown to black, and a variance in the degree of white scaling on the first abdominal tergite. A high degree of white scaling is strongly correlated with preference for a human host. It is not known whether this morphology is adaptive, but one possible explanation is that scaling is an adaptive characteristic related to desiccation resistance. Human-preferring A. aegypti aegypti tend to live in densely populated, arid areas, where they breed in pooled water generated by human settlement. These domestic human-preferring mosquitos also resist desiccation more effectively than their forest, animal-preferring cousins in the subspecies A. aegypti formosus. This study tests whether tergite scaling is an adaptation to life in arid environments and is directly linked to desiccation resistance.