Surveillance of biting midges ( Culicoides spp.) in N orthern I reland: influence of seasonality, surrounding habitat and livestock housing

Biting midges, Culicoides spp. ( D iptera: C eratopogonidae), are important vectors of viral pathogens. Following the outbreak of bluetongue serotype 8 in E urope between 2006 and 2009, many Culicoides surveillance programmes were initiated to identify vector‐active periods, in accordance with E uropean C ommission regulation 2007/1266/ EC . This study utilized surveillance data from 4 years of continuous light‐trapping at 14 sites in N orthern I reland. The number of captured Culicoides varied from none during the vector‐free period ( D ecember– A pril) to more than 36 000 per night during peak activity in the summer. The O bsoletus group represented 75% of Culicoides collected and the P ulicaris group represented 21%. A total of 91% of Culicoides were female, of which 42% were parous. Abundance data, sex ratios and parous rates suggested that both the O bsoletus and P ulicaris groups underwent three generations/year. The Obsoletus group was associated with cattle‐rearing habitats and woodland, the I mpunctatus group was found in habitats related to sheep rearing and the P ulicaris group were associated with both cattle and sheep. Housing did not reduce incursion of female O bsoletus group Culicoides but it did for males and for the P ulicaris group Culicoides . The influence of housing was strongly affected by time of year, probably reflecting the presence of livestock indoors/outdoors.