Sarcoptes Scabiel: Sarcoptic mite.

General Description: Microscopic arachnid, roughly circular in shape. Legs are short; only the first 2 pairs project beyond the body margins. Upper surface has may fine folds or ridges, and triangular scales. Pretarsi are present.

Life Cycle: Female adult mites burrow tunnels in skin and lay eggs, beginning a cycle of incomplete metamorphosis. Larvae hatch out in 3 to 5 days and burrow side tunnels or travel to the skin surface and make new tunnels or simple pockets in the outer layers of skin. Nymphs moult twice, and adult mites are produced about 17 days after eggs are laid. Mating occurs and egg laying commences 4 to 5 days later. All stages of sarcoptic mites are very susceptible to drying and can survive for only a few days off sheep. Prepatent period is 3 weeks.

Location: Face and ears are preferred, but mites may occupy all body areas in heavy infestations.

Geographical Distribution: Europe.

Significance: Sarcoptic mange is rarely a serious problem in wooled sheep.

Effect on Host: Causes mange. Crusts form and skin thickens in affected areas. Wool may be lost. Disease more frequent in winter.

Diagnostic Information: Samples fro microscopic examination may be taken from edges of lesions with a knife, scraping until bleeding begins.

Control: Overseas, subcutaneous injection of Ivermectin in infected sheep is highly effective.

Sarcoptes – male and nymph		SEM – Sarcoptes