Surveillance of biting midges (Culicoides spp.) in Northern Ireland: influence of seasonality, surrounding habitat and livestock housing

This study utilized surveillance data from 4 years of continuous light‐trapping at 14 sites in Northern Ireland. The number of captured Culicoides varied from none during the vector‐free period (December–April) to more than 36 000 per night during peak activity in the summer. The Obsoletus group represented 75% of Culicoides collected and the Pulicaris 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 Obsoletus and Pulicaris groups underwent three generations/year. The Obsoletus group was associated with cattle‐rearing habitats and woodland, the Impunctatus group was found in habitats related to sheep rearing and the Pulicaris group were associated with both cattle and sheep. Housing did not reduce incursion of female Obsoletus group Culicoides but it did for males and for the Pulicaris group Culicoides. The influence of housing was strongly affected by time of year, probably reflecting the presence of livestock indoors/outdoors. Four years' data from 14 light traps revealed that Culicoides midges were active from April to mid‐December, with three generations/year. Midges captured were mostly of the Obsoletus group (75%) and female (91%). There was a gradient of association from cattle/woodland to sheep/marginal land as: Obsoletus group > Pulicaris group > Impunctatus group. Paired indoor and outdoor trapping found that as the season progr...
Source: Medical and Veterinary Entomology - Category: Veterinary Research Authors: Tags: Original Article Source Type: research