Effects of larval rearing temperature on immature development and West Nile virus vector competence of Culex tarsalis

Background: Temperature is known to induce changes in mosquito physiology, development, ecology, and in some species, vector competence for arboviruses. Since colonized mosquitoes are reared under laboratory conditions that can be significantly different from their field counterparts, laboratory vector competence experiments may not accurately reflect natural vector-virus interactions. Methods: We evaluated the effects of larval rearing temperature on immature development parameters and vector competence of two Culex tarsalis strains for West Nile virus (WNV). Results: Rearing temperature had a significant effect on mosquito developmental parameters, including shorter time to pupation and emergence and smaller female body size as temperature increased. However, infection, dissemination, and transmission rates for WNV at 5, 7, and 14 days post infectious feeding were not consistently affected. Conclusions: These results suggest that varying constant larval rearing temperature does not significantly affect laboratory estimates of vector competence for WNV in Culex tarsalis mosquitoes.