Selection of resting areas by emerging Culicoides impunctatus (Diptera : Ceratopogonidae) on downy birch (Betula pubescens)

Resting areas utilised by Culicoides impunctatus Goetghebuer on emergence were investigated on downy birch ( Betula pubescens) in Argyllshire, Scotland. Trees examined supported large numbers of nulliparous and male C. impunctatus but no parous females, indicating that this stage does not commonly rest in this habitat during the period examined. Areas with high levels of lichen, moss and liverwort cover were preferred as resting sites at times of high C. impunctatus abundance. Males of this species showed greater activity than did females; this, together with the presence of large numbers of unmated females, could suggest that facultative mating or pre-swarm gathering takes place on these tree sites. Results presented are interpreted with regard to both the life-cycle of the species, and their value for advancing future control techniques.