Beef Cattle Lice

     Beef Cattle Lice are small but they reduce financial returns of nearly every cattle enterprise. Even moderate louse numbers can cause calves and feeders to grow more slowly and require more feed per pound of gain. Louse-infested  ows produce less milk for their calves. Cattle damage fences and bruise or scrape themselves as they rub to relieve the itching caused by millions of lice on their bodies. Blood loss from sucking lice is sometimes severe enough to cause anemia. Louse-induced anemia causes calf abortion and may even result in death of the infested animal.

     The five species of beef cattle lice found in North America include four which feed by sucking blood. These are the shortnosed cattle louse, longnosed cattle louse, little blue cattle louse, and the cattle tail louse. The fifth species, the cattle biting louse, feeds on skin tissue of cattle and does not suck blood.

All beef cattle lice spend their entire lives as parasites on living cattle. When removed from cattle they live a few days at most. The females lay eggs which they glue to individual cow hairs close to the skin of their host. Immature lice are called nymphs. Each nymph sheds its outer skin three times as it grows to adulthood. Nymphs resemble adults of the same species in feeding habits and appearance.

Shortnosed Cattle Louse, Haematopinus Eurysternus
     Although this species is seldom a problem on young calves, it causes more damage to adult beef cattle in the Great Plains and Rocky Mountain States than do all other lice.

     Adult shortnosed cattle lice are slightly over 1/8 inch long and gray-brown in color. The eggs are hard and bone-white to brown. They require from 9 to 19 days, usually 12 or 13, before hatching. The nymphs become adults within the next 12 days. Females begin laying eggs after about 4 days of adulthood. Thus, this species completes a life cycle in about 28 days, although the time may range from 3 to 6 weeks. About one out of five lice in this species is a male. Males live about 10 days. Females live 15 or 16 days, producing one or two eggs per day.

Longnosed Cattle Louse, Linognathus Vituli
     This species is opposite from the shortnosed cattle louse in that it infests calves most heavily. It is often found on mature cattle, but seldom in great numbers.

     Adults are nearly 1/10 inch long. They appear quite slender, being about one-third as wide as they are long. Their head or "nose" is noticeably pointed. Longnosed cattle lice are bluish-black in color. Their eggs, dark blue and soft shelled, require from 8 to 14 days to hatch. The egg-to-egg life cycle requires 21 to 30 days, usually about 25. Females lay about one egg per day.

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