High morphological and genetic variabilities of Ochlerotatus scapularis, a potential vector of filarias and arboviruses

Abstract

BackgroundOchlerotatus scapularis is a potential vector of filarias and arboviruses in the Neotropics. This species was once typically associated with sylvatic environments; however, cases of synanthropy and urbanization of this species have been increasingly reported in southeast Brazil. Despite the medical relevance of Oc. scapularis, its populational variability is not yet known. To our knowledge, this is the first report describing the morphological and genetic variabilities of this species.MethodsPopulation samples were characterized using the cytochrome oxidase subunit I (COI) mitochondrial gene and wing geometrics. Adult mosquitoes were collected from five sampling sites from remnants of the Atlantic forest embedded in the urban or rural areas of southeast Brazil.ResultsIn the 130 individuals analyzed, 46 COI haplotypes were detected. Haplotype diversity was high and ranged from 0.66 to 0.97. Six haplotypes were present in 61% of the individuals, whereas the remaining haplotypes were less frequent (39%). Wing shape was also highly polymorphic. Differentiation of populations across sampling sites according to genetic distances (Fst = −0.009 to 0.060) and morphological distances (Qst = 0.47) indicated that populations were not identical. No correlations were noted for phenetic and genetic diversities (p = 0.19) or for genetic or phenetic distances with geographical distances (p = 0.2 and p = 0.18, respectively).ConclusionsOur study results suggest that Oc. scapularis has a rich genetic patrimony, even though its habitat is fragmented. Implications of such genetic richness with respect to vectorial competence, plasticity, and ability to exploit urbanized areas need to be further investigated.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-015-0740-6) contains supplementary material, which is available to authorized users.

Morphogenetic characterisation, date of divergence, and evolutionary relationships of malaria vectors Anopheles cruzii and Anopheles homunculus

“…Discriminant analysis and reclassification tests were performed using the Mahalanobis distances as estimators of the metric distance. Morphological diversity based on principal component analysis was estimated according to Petersen et al (2015). Thin-plate splines were obtained by regression of the canonical scores versus the shape components using TpsRegr 1.28 (Rohlf, 2003b).…”

Culicidae fauna (Diptera: Culicidae) survey in urban, ecotonal and forested areas, from the Moreno municipality - Pernambuco State, Brazil.

“…Moreover, among the detected species, two are particularly important in the transmission of pathogens: Aedes (Ochlerotatus) scapularis (Rondani, 1848) and Aedes (Ochlerotatus) taeniorhynchus (Wiedemann, 1821). These two species are adapted to breed and feed in flooded areas and mangroves, respectively, which are normally near secondary forests 13 . Individuals of these species were found to be infected with Japanese encephalitis virus (JEV), Rocio virus (ROV), Melão virus, Dirofilaria immitis, and Wuchereria bancrofti nematodes, which are the main etiological agents for canine and human filariasis, respectively 13 .…”

Geometric morphometric wing analysis represents a robust tool to identify female mosquitoes (Diptera: Culicidae) in Germany

“…Shape and size of mosquito wings are not only species-specific. Geographically separated populations of the same species can have significant intraspecific variation in their wing morphology 22 , 56 , 57 . Furthermore, abiotic and biotic conditions of breeding habitats can influence the wing geometry through carry-over effects from the immature to the adult stage 58 – 61 .…”