Temperature and Dengue Virus Infection in Mosquitoes: Independent Effects on the Immature and Adult Stages

Abstract

Abstract. Temperature is one of the most important environmental factors affecting biological processes of mosquitoes, including their interactions with viruses. In these studies, we show independent effects of rearing temperature on the immature aquatic stages and holding temperature on the adult terrestrial stage in terms of alterations in adult survival and progression of dengue-1 virus infection in the Asian tiger mosquito Aedes (Stegomyia) albopictus. Our studies show that adult survival was determined by adult-holding temperature, regardless of rearing conditions of the immature stages. In contrast, spread of virus throughout the body of the mosquito, a pre-requisite for transmission, was reduced when the immature stages were reared in cool conditions. These results show that immature-rearing temperature selectively modified mosquito traits that influence competency for viruses, and they further our understanding of the nature of temperature effects on interactions between mosquitoes and virus pathogens and risk of disease transmission.

Larval Temperature–Food Effects on Adult Mosquito Infection and Vertical Transmission of Dengue-1 Virus

“…albopictus life history and DENV-1 infection and vertical transmission. Larval treatments were not limiting factors that influenced survivorship to adulthood, which supports results from experiments using similar larval rearing conditions (Lounibos et al 2002;Muturi et al 2011bMuturi et al , 2012Yoshioka et al 2012;Alto and Bettinardi 2013). However, we did observe species-specific patterns of treatments on larval development time.…”

“…albopictus biology and DENV vector competence. If observed larval environment-induced changes in infection and horizontal transmission also affect changes in vertical infection (Turell 1993, Alto andBettinardi 2013), then the parental environment may contribute to infection and transmission by the progeny. Further, we may expect that the relative role of vertical transmission in dengue epidemiology is dynamic and changes with environmental conditions.…”

“…Further, we may expect that the relative role of vertical transmission in dengue epidemiology is dynamic and changes with environmental conditions. Based on findings investigating single treatment effects, we predict that nutrient stress and elevated temperature may reduce barriers to dengue virus vertical transmission (Zhang et al 1993, Alto and Bettinardi 2013.…”

Responses to a warming world: Integrating life history, immune investment, and pathogen resistance in a model insect species

“…Difficulties in predicting outcomes lie not only in the need to understand the direct impact of temperature on individual components, but to also review the system as a whole, taking into account the dynamic nature of the selective pressures acting on life‐history trade‐offs across time (Alto & Bettinardi, 2013; Blanford, Thomas, Pugh, & Pell, 2003; Holland & Bourke, 2015; Laughton, Boots, & Siva‐Jothy, 2011). For example, higher temperatures may increase voltinism, potentially enabling host populations to rapidly adapt to thermal changes and infecting pathogens (Overgaard & Sørensen, 2008), but this may be tempered by reduced survival under temperature stress.…”

“…Dependence on the external environment for body temperature control has significant impacts on insect physiological functioning (Chown & Nicolson, 2004) and, subsequently, life‐history traits (Ciota, Matacchiero, Kilpatrick, & Kramer, 2014; Clissold & Simpson, 2015; Lachenicht, Clusella‐Trullas, Boardman, Le Roux, & Terblanche, 2010). Temperature effects may be particularly important when considering the immune system, as responses to temperature variation can have direct consequences for both pathogen infection and host survival (Alto & Bettinardi, 2013; Murdock, Blanford, Luckhart, & Thomas, 2014; Pamminger, Steier, & Tragust, 2016; Pounds et al., 2006; Richards, Anderson, Lord, & Tabachnick, 2012; Wolinska & King, 2009). …”