Observations on the biology of Culicoides impunctatus Goetgh. (Dipt., Ceratopogonidae) in southern England

Abstract

Catches of Culicoides spp. in a Surrey copse in 1967–69 showed the univoltine C. impunctatus Goetgh. to be dominant. This species reached peak numbers from late May to early June, when nulliparous females were commonly seen at rest on tree trunks. Proterandry was marked in catches from light-traps but not apparent in those from emergence traps or taken at rest. Biting was most frequent 1–2 h before sunset; many bites did not result in a blood-meal. Females taken at rest and from emergence traps could complete their ovarian cycle without a blood-meal, most eggs being matured by the former; midges taken biting matured the fewest eggs but could not do so without a blood-meal. Large full fat-bodies were an indication of nulliparity. It was concluded that C. impunctatus can develop the first egg-batch autogenously, and that the resting habits and responses of females to light and human bait change subsequent to the laying of the first batch of eggs.