Temperature and density-dependent effects of larval environment on Aedes aegypti competence for an alphavirus

Abstract

Mosquito larvae experience multiple environmental stressors that may modify how subsequent adults interact with pathogens. We evaluated the effect of larval rearing temperature and intraspecific larval competition on adult mosquito immunity and vector competence for Sindbis virus (SINV). Aedes aegypti larvae were reared at two intraspecific densities (150 and 300 larvae) at 20° C and 30° C and the adults were fed artificially on citrated bovine blood containing 10 5 plaque forming units of SINV. Expression of cecropin, defensin, and transferrin was also evaluated in one-and five-day-old female adults. There was a direct relationship between larval density and SINV infection and dissemination rates at low temperature (20° C) and an inverse relationship between larval density and SINV infection rate at high temperature (30° C). Cecropin was only expressed in five-day-old adults that were raised at high temperature as larvae and was 20-fold over-expressed at low compared to high density treatments. Defensin and transferrin were under-expressed in one-day-old adults and overexpressed in five-day-old adults in all competition-temperature combinations relative to low density treatments at 20° C. These findings suggest that interaction between biotic and abiotic conditions of the larval environment may alter adult mosquito immunity resulting in enhanced vector competence for arboviruses. Journal of Vector Ecology 37 (1): 154-161. 2012.

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.…”

“…An expansive literature demonstrates that the environmental factors experienced by an adult female mosquito can affect her vector competence, the innate ability of the vector to support replication and transmission of a pathogen (Turell 1993, Richards et al 2007). Additionally, growing evidence suggests that effects of the larval environment can continue through the adult stage to also influence vector competence, because innate immunity, infection barriers, and escape barriers develop during larval stages (Grimstad and Walker 1991;Reiskind and Lounibos 2009;Muturi et al 2011aMuturi et al , 2012Alto and Lounibos 2013). In particular, the interaction between larval temperature and nutrient availability may affect mosquito biology and vector competence, especially for container mosquitoes (Padmanabha et al 2011).…”

Effect of food types on competitive interaction between Aedes aegypti (LINNAEUS, 1762) and Ae. albopictus (SKUSE, 1894) (Diptera, Culicidae): a proximate level appraisal

“…Similar conditions are observed in Aedes mosquitoes in other natural larval habitats (BRADSHAW & HOLZAPFEL 1992, CLEMENTS 1992, RENSHAW et al 1994, which affects larval development and population growth (BROADIE & BRADSHAW 1991, RENSHAW et al 1994, MUNSTERMANN & CONN 1997, LORD 1998. Such competitive interactions and resultant effects on the prospective viral role have been established by different studies (ALTO et al 2008a, 2008b, PADMANABHA et al 2011, MUTURI et al 2012. Exploration of resourcebased competition and its effect on the life history traits of Ae.…”

Comparative account of energy reserves in four co-occurring mosquito species in Kolkata, India (Diptera: Culicidae)

“…In different species of mosquitoes the correspondence among pupal weight, wing length, longevity and fecundity justifies the use of one or many life history traits as markers of fitness at the individual or population level (BLACKMORE & LORD 2000, PADMANABHA et al 2011a, 2011b, MUTURI et al 2012. The amount of energy reserves in an individual mosquito can also be included as an indicator of fitness, owing to the correspondence with multiple life history traits (MOSTOWY & FOSTER 2004, BARGIELOWSKI et al 2012, MAÏGA et al 2012, KAUFMANN et al 2013.…”