Biology subjects

Evans, M. V.

Publications and source records attributed to Evans, M. V..

3 recordsLinked to original sources

bioRxiv2017

Carry-over effects of larval microclimate on the transmission potential of a mosquito-borne pathogen

Climate shapes the transmission of mosquito-borne pathogens through impacts on both the vector and the pathogen. In addition to direct effects of the environment, carry-over effects from previous life history stages can influence mosquito traits relevant to disease transmission. While this has been explored in a laboratory setting, the net effect of temperature-mediated carry-over effects due to relevant environmental variation in the larval stage is ambiguous. Here, we use data collected from a semi-field experiment investigating dengue dynamics in Aedes albopictus across a natural environmental gradient to parameterize a dengue transmission model. We reared Ae. albopictus across three different land classes characterized by their proportion of impervious surface. Emerged females were offered a dengue infectious bloodmeal, kept at a constant 27 {degrees}C, and assayed for infection, dissemination, and infectiousness 21 days post infection. Incorporating carry-over effects of larval environment on measures of vector competence resulted in lower predicted dengue transmission potential across land class and season, however a strong positive relationship with larval environmental temperature remained. Given the significant impact of carry-over effects, future mechanistic models of disease transmission should include both direct and carry-over effects of environmental temperature.

ecology↗

bioRxiv2017

Anticipating Emerging Arboviruses: What Comes After Zika?

New vector-borne diseases have emerged on multiple occasions over the last several decades, raising fears that they may become established within the United States. Here, we provide a watchlist of flaviviruses with high potential to emerge in the US, identified using new statistical techniques for mining the associations in partially observed data, to allow the public health community to better target surveillance.

ecology↗

bioRxiv2016

Fine-scale variation in microclimate across an urban landscape changes the capacity of Aedes albopictus to vector arbovirus

Most statistical and mechanistic models used to predict mosquito borne disease transmission incorporate climate drivers of disease transmission by utilizing environmental data collected at scales that are potentially coarser than what mosquito vectors actually experience. Temperature and relative humidity can vary greatly between indoor and outdoor environments, and can be influenced strongly by variation in landscape features. In the Aedes albopictus system, we conducted a proof-of-concept study in the vicinity of the University of Georgia to explore the effects of fine-scale microclimate variation on mosquito life history and vectorial capacity (VC). We placed Ae. albopictus larvae in artificial pots distributed across three replicate sites within three different land uses - urban, suburban, and rural, which were characterized by high, intermediate, and low proportions of impervious surfaces. Data loggers were placed into each larval environment and in nearby vegetation to record daily variation in water and ambient temperature and relative humidity. The number of adults emerging from each pot and their body size and sex were recorded daily. We found mosquito microclimate to significantly vary across the season as well as with land use. Urban sites were in general warmer and less humid than suburban and rural sites, translating into decreased larval survival, smaller body sizes, and lower per capita growth rates of mosquitoes on urban sites. Dengue transmission potential was predicted to be higher in the summer than the fall. Additionally, the effects of land use on dengue transmission potential varied by season. Warm summers resulted in a higher predicted VC on the cooler, rural sites, while warmer, urban sites had a higher predicted VC during the cooler fall season.

ecology↗