The Suquía River basin (Córdoba, Argentina) is under a strong negative impact due to multiple sources of anthropic pollution. The main goal of our study was to evaluate if variations in the water quality of Suquía river basin affect the reproductive biology of and determine if the responses provided by the species can be considered as biomarkers of river quality. This assessment was performed through the measurement of morphological, histological and somatic parameters in adult males collected at four sampling sites during the beginning and the end of the breeding season. The water quality evaluation carried out through the estimation of a water quality index (WQI) and pesticides concentrations in water, revealed a pollution gradient along the studied basin. The same variation pattern was registered for the somatic index. In addition, the analysis of the morphology of the male copulatory organ (gonopodium) showed that individuals collected at Córdoba city had the lowest Gonopodium-Somatic Index (Gonop-SI) value, while those sampled at the most polluted site showed abnormalities in the small structures of the gonopodium. On the other hand, few histological alterations were found in the liver whereas no alterations were found in gonads along the river. The results obtained allowed us to characterize the environmental conditions of the studied basin and demonstrated the water quality deterioration along the Suquía River.
Ornithophilic Culex species are considered the primary amplification vectors of West Nile virus (WNV) in bird hosts as well as vectors responsible for epidemic transmission. Culex coronator was first collected from Okaloosa, Santa Rosa, Walton, and Washington Counties in Florida in 2005 and has since spread throughout the state. The vector competence of Cx. coronator for WNV, known to be infected in nature, has not been assessed. Without this knowledge, we are unable to assess this species' potential as an enzootic and epidemic vector of WNV in Florida. In the current study, we investigate the reproductive biology and susceptibility to WNV infection, dissemination, and transmission by Cx. coronator . We show that Cx. coronator is capable of delaying oviposition for several weeks after blood feeding and that the number of eggs laid is greater for avian than mammalian hosts. Cx. coronator were highly susceptible to infection (∼80–100%) and dissemination (∼65–85% by 18 days since exposure) with lower rates of transmission (0–17% at 25°C and 28–67% at 28°C), suggesting that it is a competent vector of WNV under some conditions. The proportion of mosquitoes with disseminated infections related to the time since exposure and was higher at 28°C than at 25°C. The rapid and statewide distribution of Cx. coronator throughout Florida poses as a potential public health risk. This baseline knowledge is essential information for mosquito control and public health agencies to assess current and future disease risk to Southeastern United States.