Sheep Ked
Melophagus ovinus (Linnaeus), Hippoboscidae, DIPTERA


DESCRIPTION

Adult -- The adult sheep ked or sheep tick is a wingless, blood-sucking fly that is 5 to 7 mm in length. It is reddish-brown in color wit h the head short and sunken into the thorax and a sac-like body that is leathery and spiny.

Egg -- Eggs are retained within the body of the female.

Larva -- The larvae are fully grown and sticky when extruded by the female and stick in the wool.

Pupa -- Sheep ked pupae are chestnut brown and are stuck in the wool on the belly, shoulders, and thighs.

BIOLOGY

Distribution -- Sheep keds are found throughout the United States and other areas of the world in which sheep are raised.

Hosts -- Sheep are the only known host animals of the sheep ked.

Damage -- Primarily, damage is to lambs. High ked populations cause unthriftiness and emaciation.

Life History -- The entire life cycle of the ked is spent on sheep. Adult keds survive only 2 to 8 days when off the host. Eggs are retained within the body of the female. The female ked extrudes one mature larva every 7 to 8 days. The larva immediately pupates. Pupae can be found commonly on the belly, shoulders, and thighs throughout the year. The total life cycle may take from 3 to 6 weeks, depending on temperature. The adults live 3 to 4 months and bear 10 to 12 larvae in this time.


CONTROL

Control is best achieved by application of chemical insecticides immediately after shearing. About half of the adults and most of the pupae are removed with the fleece. Better coverage with insecticides is possible on newly shorn animals.