Abstract
Introduction and ObjectivesThe spread of the Flaviviruses West Nile (WNV) and Usutu (USUV) in Europe has highlighted the critical need to comprehend the enzootic cycles of these pathogens for effective decision-making. These viruses are part of a complex disease cycle that involves birds as principal hosts and humans as dead-end hosts. Our study aims to visualize the intricate relationships between the main vector of this viruses, Culex pipiens, and its host preference for several host species, primarily birds, and the potential changes into a land use gradient that could pose a risk factor in WNV and USUV transmission.Materials and MethodsWe conducted mosquito sampling for host-seeking and engorged females, coupled with bird censuses in the Camargue region in southern France, where these two viruses’ co-circulation had been well reported. Several localities were sampled monthly along a land-use gradient of peri-urban, agricultural, and natural areas from May to November 2021. Engorged Cx pipiens were analyzed by PCR amplification and sequencing of mitochondrial 12S and 16S DNAResultsCulex pipiens was found to feed primarily on birds and mammals. We identified 55 vertebrate species in 110 engorged Cx pipiens, 51 bird species, two mammals, one amphibian, and one reptile, The Forage ratio was estimated for several bird species. Based on these results, we described a preference of Cx. pipiens in Camargue to selectively bite Columbia livia domestica in rural areas and Passer montanus in agricultural and peri-urban areas. Passeriformes is the order preferred to be bitten by Culex pipiens.Discussion and ConclusionIn our analysis, Columbia livia and Passer montanus have been identified as potential super-spreader. Results demonstrate species selection and discuss interactions concerning West Nile host competence and potential Flaviviral transmission risk. These results will be helpful in disentailing host-vector interactions and the relationship between bird diversity and emerging mosquito-borne disease.