Abstract: Aedes aegypti is an important vector of many viruses that affect human health, and is the species responsible for the autochthonous dengue outbreaks in Key West in 2009 and Key Largo in 2020, FL, USA. Before transmission can occur, a virus must undergo an extrinsic incubation period within a mosquito. For dengue, this period can last between 6-14 days. Therefore, mosquito abatement efforts should focus on targeting the mosquitoes old enough to transmit the virus. Yet, aging mosquitoes is a difficult task and few methods exist to chronologically age mosquitoes. In this experiment, we used transcriptional profiling to measure the changes of two age-dependent genes, Sarcoplasmic calcium binding protein 1 and Aquaporin-11, within a known age group of Ae. aegypti. We used the known age group to develop a model that could predict the ages of field-collected mosquitoes, and divide them into three epidemiological significant categories: pre-EIP (1-5 days old), within-EIP (6-14 days) and post-EIP (15+ days). Mosquitoes were collected from October through November 2020 during the end of the Key Largo dengue outbreak. Our results indicated that at least half of the mosquitoes collected from Key West, Marathon, and Key Largo could be old enough to survive through the dengue EIP. These data provide baseline mosquito longevity in a post-outbreak situation, and elucidates potential future outbreaks as it pertains to mosquito survival. Age grading field-collected mosquitoes via transcriptional profiling can provide public health and mosquito control agencies with information to help them to better understand a vector population’s capacity to transmit dengue.
