EM 4414 May 1979

CONTROL OF KED S

The sheep ked or sheep "tick," Melophagus sents a of that are parasitic on such ovinus, is found on sheep in most sheep-raising mammals as deer, goats, and sheep. There are . areas of the world. In the United States it is species that prey on some birds. most abundant in the west. The sheep ked spends its whole life cycle on the Symptomology and Economics host. Sheep keds that become dislodged do not usually post a threat of reinfestation to other The sheep ked is a pest only of domestic or sheep. Dislodged keds only live about four days mountain sheep and goats. There are no alter­ off their hosts. Spread is almost entirely from nate host and no free-living stages. sheep to sheep, although man (shearers, etc.) can help to spread them. Keds generally infest the neck, breast, shoulders, belly, and thighs, and can be easily detected by . The ked is tick-like in appearance, about 1 /4 inch parting the wool. They pierce the skin and neck long, and reddish or gray-brown in color. It is and suck blood causing great irritation to the unusual in not laying eggs. Eggs are produced sheep and forcing them to scratch and bite at singly, are retained in the uterus, and hatch themselves. Scratching results in wool tags left there. The young larva remains within the fe­ on fence wires. male ked, feeding from special nutritive glands until it is·fully developed. Only one develops at a Heavily infested animals become weak and un­ time. When full development is reached, each thrifty and show weight loss, anemia, wool stain­ larva is expelled almost immediately forming a ing, reduceq resistance to disease, and a condition puparium that attaches to the wool. called "cockle." Cockles are raised bump-like skin blemishes oaused by ked bites. They reduce the value of the skin.

Young animals are the most susceptible to ked infestation, because keds migrate to the lambs after ewes have been sheared. In some areas, up to 25% reduction in fleece yields have been noted.

Description and Life History

The sheep ked is frequently called a sheep tick, but is a true rather than a tick. It repre- Adult sh eep ked.

COOPERATIVE EXTENSION SERVICE • COLLEGE OF AGRICULTURE • WASHINGTON STATE UN IVERSITY • PULLMAN In cooperation with the United States Department of Agriculture Issued in furtherance of the Acts of May 8 and June 30, 1914, by the Washington State University Cooperative Extension Service, J. 0. Young , Director EM 4414 - Page 2

Dosage* Amt. insecticide per 100 gal/spray or, use as Insecticide indicated Interval between application and slaughter remarks**

Diazinon 0.03% as spray 0.5 lb. 50% W.P. Do not treat within 14 days of slaughter. Do not use on 2% as dust 1.5 oz. per goats.

Co-Ra! 0.125% as spray 4 lbs. 25% W.P. Do not apply within 1 S days of slaughter. Do not use on or dip (sheep and goats) lactating dairy goats. Do not use within 14 days of 0.5% as dust 1 to 2 oz. per animal freshening of dairy goats. (sheep only)

Toxaphene 0.5% as spray 10 lbs. 40% W.P. or Do not apply within 28 days of slaughter. Do not use 1/2 gal. 8 lb/gal E.C. on dairy goats. 0.25% as dip S lbs. 40% W.P. or 0.25 gal. 8/lb gal E.C . 5.0% as dust 1 to 2 oz. per animal

Malathion 0.5% as spray 16 lbs. 25% W.P . or No time limitation between application and slaughter. 1 gal 57% E.C. Do not apply to dairy goats. 5% as dust 1 to 2 oz. per head

R onne/ (Kor/an) 0.25% as spray 1 gal. 25% E.C. Do not apply within 28 days of slaughter. Do not use 2% as spot-on Do not dilute. Apply on lactating dairy goats. Do not use within 7 days of (Also available as along back line at rate of freshening of dairy goats. Use within 6 weeks of shearing. a pour-on. Check 3 cc/SO lbs. weight. Use as Do not re-treat within 2 weeks, nor within 28 days. label for instructions.) indicated on label.

*E.C.=emulsifiable concentrate; W.P.=wettable powder. **Observe label precautions.

The puparium is barrel-shaped, dark reddish Control brown, and about 1/8 inch long. During warm months, the adults emerge from the puparium in Several insecticides registered for control of about three weeks; about six weeks are required sheep keds on sheep are listed above. Sheep can during cold months. be sprayed, sprinkled, dipped, or dusted. (Goat treatments are included.) The best time to treat Female keds live for about five to six months sheep is in spring, after shearing, when the wool during which time they may produce up to two is short and shear cuts have healed. Sheep sprayed dozen young at a rate of about one every seven during cold weather are more subject to stress. days. If liquid treatments are used, there should be Ked populations build up during the fall and time to allow drying before evening. Do not early winter months, begin to peak during the spray animals when daytime temperatures are first of the year, then decline until early summer. below 40° F. The decline is associated with resistance of the sheep at this time. The blood flow to the outer Management Suggestions skin layer is cut off, causing ked starvation. There is also cellular infiltration to sites of ked (A) Small Farm Flocks feeding, blocking the free flow of blood to the parasite. Sheep keds can be easily controlled in small EM 4414 - Page 3

farm flocks by attaching a dust bag in a barn shoulder. When treating just a few sheep, opening used by the flock. Other barn ac­ hand sprinkling, hand dusting, or a pour-on cesses should be closed in order to cause treatment are probably the most convenient forced usage of the dust bag by the sheep as methods of control. they enter and exit. (B) Commercial Flocks Dust bags should contain one of the recom­ Large commercial flocks can be treated for mended pesticides listed and may be a com­ infestations most economically by dipping or mercial product or simply made from two spraying after shearing, and spraying again in burlap bags placed one inside the other. the fall. Co-Ral and Korlan have shown good Hang dust bag at the height of the animal's results for spray applications.

Prepared by Art Antonelli, Extension Entomologist and Ty Clark, Area Livestock Agent, Western Washington

Assistance from Washington State University is available to all persons, without regard to race, color, or national origin. Trade names have been used to simplifr the presentation of information. No endorsement of products is intended.

Use p2siicides with care. Read the label and fol low ils dir ections. Never smoke while us ing pesti­ cides and avoid breaihing ihe spray or dust. Wear natural rubber gloves when handling pesticides. Wash hands and face carefully with soap and water after applying. If insecticides are spilled on skin or clothing, remove ·contaminated clothing and wash skin thoroughly. Store pesticides in their original containers and be sure labels remain on the containers. Keep containers away from food or feed and out of reach of children or irresponsible persons. -- 1