Culicoides insignis in Ecuador: Molecular identification of blood meals and detection of bluetongue virus

Abstract

Bluetongue virus (BTV) is an Orbivirus transmitted by Culicoides biting midges and is the causative agent of bluetongue disease in wild and domestic ruminants. Culicoides insignis is the primary vector of BTV in Florida, Central America, the Caribbean, and South America. In Ecuador, recent investigations have reported the presence of BTV in cattle and identified C. insignis as the dominant species in localities from the Amazon Basin and Andean foothills. Understanding the host-feeding patterns of blood-feeding insects and evaluating their role in pathogen transmission are essential for elucidating the epidemiology of vector-borne diseases. To that end, we investigated the presence of BTV in unengorged C. insignis females collected in two localities: Cotundo, where BTV had previously been reported in cattle, and Paraiso Escondido located near (∼35 km) a site with a known history of BTV circulation. A total of 1773 female Culicoides spp. specimens were collected, of which 326 (18.38 %) were C. insignis. We identified the blood meal sources of engorged C. insignis females from both localities. Our results provide additional evidence to support the role of C. insignis as vector of BTV in Ecuador.