A mass attack by the biting midge culicoides nubeculosus (Mg.) (Dipteria, Ceratopogonidae) on grazing cattle in Denmark. A new aspect of sewage discharge.

A consequence of sewage discharge into a shallow marsh pool was large-scale hatching of the biting midge Culicoides nubeculosus from the recipient and mass attacks by this blood-sucking insect on grazing cattle. Culicoides nubeculosus is a great nuisance due to the painful bite and in Denmark it is a potential vector of pathogenic agents. In the future, these aspects of sewage discharge must be borne in mind.