Status of Dorper sheep as hosts of ectoparasites

Seventeen ixodid tick species or subspecies have been collected from Dorper sheep in South Africa. The diseases transmitted or the conditions caused b y these ticks in sheep are discussed. Although Dorper sheep may be infested with the scab mite, Psoroptes ovis, this does not seem to cause production losses. These sheep may, however, serve as a source of mite infestation fo r woolled sheep. The majority of Dorper sheep are infested with the larvae of the nasal bot fly, Oestrus ovis, they may also be subject to myiasis cau sed by the larvae of two calliphorid flies. In certain regions of the count ry Dorper sheep are prone to serious fly worry by female Simulium chutteri. Although Dorper sheep may be infested by various louse species these do no t seem to reach large numbers or cause production losses. (C) 2000 Elsevier Science B.V. All rights reserved.