First molecular identification of the vertebrate hosts of Culicoides imicola in Europe and a review of its blood-feeding patterns worldwide: implications for the transmission of bluetongue disease and African horse sickness

Culicoides (Diptera: Ceratopogonidae) are vectors of pathogens that affect wildlife, livestock and, occasionally, humans. Culicoides imicola (Kieffer, 1913) is considered to be the main vector of the pathogens that cause bluetongue disease (BT) and African horse sickness (AHS) in southern Europe. The study of blood-feeding patterns in Culicoides is an essential step towards understanding the epidemiology of these pathogens. Molecular tools that increase the accuracy and sensitivity of traditional methods have been developed to identify the hosts of potential insect vectors. However, to the present group's knowledge, molecular studies that identify the hosts of C. imicola in Europe are lacking. The present study genetically characterizes the barcoding region of C. imicola trapped on farms in southern Spain and identifies its vertebrate hosts in the area. The report also reviews available information on the blood-feeding patterns of C. imicola worldwide. Culicoides imicola from Spain feed on blood of six mammals that include species known to be hosts of the BT and AHS viruses. This study provides evidence of the importance of livestock as sources of bloodmeals for C. imicola and the relevance of this species in the transmission of BT and AHS viruses in Europe.

This study was partially funded by projects CGL2015‐65055‐P from the Spanish Ministry of Economy and Competitiveness, P11‐RNM‐7038, from the Junta de Andalucía and a Microproyecto funded by the internal Estación Biológica de Doñana proposal financed by the Spanish Ministry of Economy and Competitiveness through the Severo Ochoa Centres of Excellence in Research, Development and Innovation programme (SEV‐2012‐0262). Funds were also partially provided by EU grant HEALTH.2010.2.3.3‐3 project 261391 EuroWestNile. JM‐dlP and MF were funded by a Juan de la Cierva contract and a Formación de Profesorado Universitario grant, respectively.