SOME FACTORS GOVERNING THE ENTRY OF CULICOIDES SPP. (DIPTERA, CERATOPOGONIDAE) INTO STABLES

The entry of Culicoides species into stables was examined by comparing the numbers of midges caught with identical light-traps under differe nt conditions. The comparison was made between collections made inside an empty stable, a regularly cleaned stable and a dirty stable and th ose made outside the stables in a sleeping space open on two sides. Th e work was first done in the presence of cattle and sheep in adjoining paddocks and then repeated in their absence. A positive correlation w as found between the numbers of C. imicola females caught out of doors and inside a clean stable. Removal of the cattle and sheep resulted i n a reduction in the numbers of C. imicola caught inside and outside t he stables. In contrast, the numbers of Culicoides spp, that prefer to feed on birds was not affected by the removal of the cattle and sheep . Their entry into the stable was proportionate to the size of the ent rances into the sleeping space and the size of the stable door and pre sumably occurs passively. On the other hand, the numbers of C. imicola females entering the same stables were somewhat enhanced by the prese nce of horses inside the stables and by odours associated with dirty s tables.