Abundance and diversity of Culicoides species (Diptera: Ceratopogonidae) in different forest landscapes of Karnataka, India: implications for Culicoides borne diseases

Abstract

Culicoides are important vectors for livestock and human pathogens. Wild animals act as reservoirs for important orbiviruses such as bluetongue and African horse sickness viruses. There are only limited studies on the distribution of Culicoides species in forest habitats. In this study, we collected Culicoides from different wildlife sanctuaries and national parks of Karnataka. We collected and morphologically identified 8597 Culicoides. We found 18 species of Culicoides in different sites, with C. oxystoma and C. imicola being the predominant species across the sites. The sequence alignment and phylogenetic analysis of the Cox1 gene of Cuilicoides species revealed a huge level of sequence similarity and their wide distribution around the world. Most of the isolates from our study were closely related to Chinese isolates. The abundance of the species was analyzed using the Bayesian ordination method. We used a hierarchical joint distribution negative binomial regression model to detect the correlation between species owing to environmental covariates and residual correlation. The presence of potential vectors for important livestock pathogens in wild habitats in our study warrants further research on the detection of pathogens in Culicoides collected from forest habitats and adopt surveillance in wild animal habitats to prevent disease spread from wild animals to livestock and vice versa.