Abstract:
A total of 33 564 Culicoides midges was collected in 44 light trap collections made at 22 sites in the Stellenbosch area during November 1986. Of the 23 species present in these collections 8 were frequently encountered namely, C. magnus, C. imicola, Culicoides sp. 49, C. zuluensis, C. gulbenkiani, C. pycnostictus, C. distinctipennis and C. nivosus. Although C. magnus was abundant at all trap sites, the prevalence of the other species appeared to be affected by the proximity of the light trap to different host animals and/or larval habitats. Plain-wing species and members of the C. schultzei group were rarely collected. The larval habitats of most of the above species were located by the use of tent-type emergence traps. All these habitats were found on irrigated pastures or where drainage water had accumulated . The difference in the requirements of the various species was associated with certain factors, such as degree of moisture, the type and amount of organic matter present and the particle size of the underlying soil. The identity of the blood-meals of 69 individual Culicoides belonging to 7 species was determined. The 5 commonest species had all fed on cattle and 4 of these on sheep. Two species, C. pycnostictus and C. distinctipennis were positive for bird blood.
