Flies associated with cattle in south west Scotland during the summer months.

The sheep headfly, Hydrotaea irritans, and Morellia simplex were the species most frequently associated with cattle at pasture and comprised 69.01 per cent and 13.93 per cent, respectively, of the total fly collection made from grazing cattle. The most prevalent biting fly was Haematobosca stimulans which comprised 4.46 per cent of the total catch. A few clegs, Haematopota pluvialis, and horse flies, Hybomitra distinguenda, were also recorded. A few of the headflies swarming around cattle entered milking parlours and byres and made up, at 38.23 per cent, the highest percentage of the total fly collection from these buildings. Headflies congregated on the windows, particularly those in the roof. Lesser numbers of the flies, Hydrotaea albipuncta, Morellia simplex and Trichopticoides decolor, with similar feeding habits to H irritans were also collected from these windows with a number of those species attracted to excrement. The biting muscids, Stomoxys calcitrans and Haematobosca stimulans, were collected mainly from the outside surfaces at the entrance to milking parlours and byres and comprised 23.53 per cent and 11.18 per cent, respectively, of the total fly collection from these buildings. Stomoxys calcitrans, the stable fly was present on every sample taken from calf houses and comprised 63.79 per cent of the total fly collection from these houses. Two other species, Sepsis violacea and the common housefly Musca domestica, were present on occasions in significant numbers and comprised 20.69 per cent and 9.48 per cent, respectively, of the total fly collection from calf houses.