Scoping review of Culex mosquito life history trait heterogeneity in response to temperature

Abstract

Background: Mosquitoes in the genus Culex are primary vectors in the US for West Nile virus (WNV) and other arboviruses. Climatic drivers such as temperature have differential effects on species-specific changes in mosquito range, distribution, and abundance, posing challenges for population modeling, disease forecasting, and subsequent public health decisions. Understanding these differences in underlying biological dynamics is crucial in the face of climate change.

Methods: We collected empirical data on thermal response for immature development rate, egg viability, oviposition, survival to adulthood, and adult lifespan for Culex pipiens, Cx. quinquefasciatus, Cx. tarsalis, and Cx. restuans from existing literature according to the PRISMA scoping review guidelines.

Results: We observed linear relationships with temperature for development rate and lifespan, and nonlinear relationships for survival and egg viability, with underlying variation between species. Optimal ranges and critical minima and maxima also appeared varied. To illustrate how model output can change with experimental input data from individual Culex species, we applied a modified equation for temperature-dependent mosquito type reproduction number for endemic spread of WNV among mosquitoes and observed different effects.

Conclusions: Current models often input theoretical parameters estimated from a single vector species; we show the need to implement the real-world heterogeneity in thermal response between species and present a useful data resource for researchers working toward that goal.

Keywords: Arboviruses; Climate change; Culex; Culicidae; Temperature; West Nile virus.

Fig. 1

Culex mosquito life cycle, key traits, and their role in the West Nile virus (WNV) transmission cycle. Definitions of life history traits examined in this study (left), life stages (center), and enzootic circulation among mosquitoes and birds (top right)

Fig. 2

Literature search and filtering protocol. Identification level consisted of searching databases. Level 1 screening eliminated records by title and abstract according to Level 1 criteria, and Level 2 screening eliminated full-text articles after careful review according to Level 2 criteria

Fig. 3

Life history trait response to temperature in four Culex mosquito species. Left to right: Culex pipiens, Cx. quinquefasciatus, Cx. restuans, and Cx. tarsalis; traits top to bottom: immature development time in days, percent egg viability, adult lifespan in days, oviposition in number of eggs per egg raft, and percent immature survival. Mosquito origin indicated by color: green = field collected, pink = laboratory colony, gray = unspecified or unclear. Temperature measurement type indicated by shape: circles = air temperature, squares = water temperature, triangles = unspecified or unclear. Type of fit indicated by line type: solid = linear model, dashed = quadratic model. See Table 2 for key summary values, Additional file 1: Dataset S1 for the full dataset used to generate this figure and Additional file 5: Table S5 for descriptions of the fitted functions

Fig. 4

Temperature-dependent WNV mosquito $R_0^T$ for Culex pipiens (left column), Cx. quinquefasciatus (center column), and Cx. tarsalis (right column) under average seasonal temperature conditions from 2010–2020 (top row) and under a 3 °C increase scenario (bottom row). Note that several sources of variability exist in the underlying data which may result in unquantified uncertainty