The Effect of Temperature on Life History Traits ofCulexMosquitoes

Abstract

Climatic changes forecasted in the coming years are likely to result in substantial alterations to the distributions and populations of vectors of arthropod-borne pathogens. Characterization of the effect of temperature shifts on the life history traits of specific vectors is needed to more accurately define how such changes could impact the epidemiological patterns of vector-borne disease. Here, we determined the effect of temperatures including 16, 20, 24, 28, and 32°C on development time, immature survival, adult survival, mosquito size, blood feeding, and fecundity of both field and colonized populations of the Culex mosquitoes Culex pipiens L., Culex quinquefasciatus Say, and Culex restuans Theobald. Our results demonstrate that temperature significantly affects all of these traits, yet also that the extent of this effect is at times incongruent among temperatures, as well as being population and species-specific. Comparisons of colonized mosquitoes with field populations generally demonstrate decreased adult and immature survival, increased blood feeding and egg production, and significant variation in the effects of temperature, indicating that such colonies are not fully representative of natural populations. Results with field populations in general indicate that increases in temperature are likely to accelerate mosquito development, and that this effect is greater at temperatures below 24°C, but also that temperature significantly increases mortality. Among field populations, Cx. restuans were most affected by temperature increases, with decreased longevity relative to other species and significant increases in adult and immature mortality measured with each incremental temperature increase. Despite the unique climates characteristic of the geographic ranges of Cx. quinquefasciatus and Cx. pipiens, evidence of significant species-specific adaptation to temperature ranges was not seen. Taken together, these results indicate that geographic region, as well as species and population differences, must be considered when measuring the effect of temperature on vector populations.

Complexity of virus–vector interactions

“…However, in spite of their distinct geographic ranges, evidence of significant species-specific adaptation to temperature ranges was not seen [56]. Similarly, strong and consistent non-linear effects were measured in life history traits of distinct populations of C. pipiens across an altitudinal and latitudinal gradient in the eastern United States, with lack of support for local thermal adaptation [57].…”

Can Reconstructed Land Surface Temperature Data From Space Predict a West Nile Virus Outbreak?

“…We then estimated a series of biologically meaningful variables that are known or hypothesized to affect mosquito populations, WNV transmission or disease risk. The thresholds used for deriving LST-related variables were drawn from bibliography on both mosquitoes survival and development and virus amplification (Rueda et al, 1990, Vinogradova, 2000, Reisen et al, 2006, Tachiiri et al, 2006, Gong et al, 2011, Ciota et al, 2014. The following list of annual indices were derived from reconstructed daily LST:…”

“…Since it was previously suggested that climatic conditions (higher temperatures, especially) might have favored the occurrence of the 2010 WNV outbreak in Greece (Danis et al, 2011) and Europe in general , our main objective was to identify temperature-related variables that might show temporal differences in localities with reported human cases and spatio-temporal differences in areas with and without WNV infection. To this aim we estimated diverse indices that are known or hypothesized to represent limiting or favoring conditions for either mosquito or pathogen development and survival based on thresholds reported in the literature (Rueda et al, 1990, Vinogradova, 2000, Reisen et al, 2006, Tachiiri et al, 2006, Gong et al, 2011, Ciota et al, 2014.…”

The role of Culex pipiens mosquitoes in transmission of West Nile virus in Europe

“…increased viral replication at higher temperatures (Chamberlain & Sudia 1961, Hardy et al 1983), but it also affects mosquitoes in several ways, such as decreased duration of the gonotrophic cycle, and increased biting rate at higher temperatures (Ciota et al 2014, Platonov et al 2008. These effects together result in higher vector competence for WNV at higher temperatures (Fros et al 2015a, Vogels et al 2016a), which, in its turn, contributes to a higher risk of WNV establishment .…”

“…Although higher temperatures have a positive effect on vector competence of Cx. pipiens for WNV and the EIP (chapters 4 and 5; Dohm et al 2002, Fros et al 2015a, Fros et al 2015b, Kilpatrick et al 2008, they also negatively affect survival (Ciota et al 2014). No studies have yet investigated the interaction between temperature and WNV infection on survival of Cx.…”