Sheep chewing louse
The sheep chewing louse, scientifically known as Bovicola ovis, is a common parasitic insect that affects sheep and, in some instances, dogs, particularly those in close contact with sheep. This small insect, which measures 1 to 2 millimeters in length, resides on the skin beneath the wool, feeding on skin flakes, bodily fluids, and blood. Characterized by its chewing mouthparts, it differs from other lice species that suck blood. The louse has a distinct body structure, featuring a large head with sensory antennae, a small thorax, and a segmented abdomen equipped with claws for gripping the host's wool.
In terms of reproduction, a female sheep chewing louse can lay up to 100 eggs every three days, adhering them to the wool with a fast-drying glue. The hatching process occurs about nine days later, and young lice undergo several molts over three to four weeks before reaching adulthood. Without intervention, the presence of these lice can cause skin irritation and discomfort for the sheep. To control infestations, shepherds often use chemical treatments known as sheep dips, which effectively eliminate the lice. Overall, understanding the biology and life cycle of the sheep chewing louse can help in managing the health of sheep in farming and ranching contexts.
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Sheep chewing louse
A common problem for shepherd or sheep ranchers is sheep chewing louse infecting their sheep. This tiny insect lives on the skin beneath the wool and feeds on flakes and fluids in the skin as well as blood.
Kingdom: Animalia
Phylum: Uniramia
Class: Insecta
Order: Phthiraptera
Family: Trichodectidae
Genus: Bovicola
Species: Ovis
One mammal species commonly infected by a parasitic louse is the sheep. The louse receives its name because it usually lives on sheep, but it can live on dogs. This may be true especially for a sheep herding dog in close contact with the sheep. It is called the chewing louse because its mouthparts are designed for chewing. Other lice species, like the sucking lice (subfamily Anoplura), are designed for sucking blood and fluids.
The small, flat sheep-chewing louse is divided into three sections. The large, round head has two long, thick antennae for sensing its surroundings. These are one of its main sensory organs since its eyes are small or absent. Behind the head is the small thorax, or mid-body section. Attached to this section is a pair of short legs. Two pairs of legs are attached to the forward part of the abdomen or a lower-body section. Each leg has a claw for gripping the sheep's body and wool. The abdomen is oval-shaped and has ring-like segments. Many tiny hairs cover the abdomen and aid in sensing the surroundings. The louse is one to two millimeters long. It is light-colored, probably white or yellow.
This insect is a parasite. A parasite may be either a plant or an animal that lives and feeds inside or on the outside of another plant or animal. The sheep-chewing louse makes its home on the skin of sheep. Its diet is flakes of skin, fluids the skin releases, and blood beneath the skin. Sharp mouthparts make tiny biting wounds. As the louse feeds, it releases a chemical that keeps the blood from clotting and which causes the skin to become red and itch.
A shepherd or sheep rancher may rid the sheep of the louse with strong poisonous chemicals called sheep dip. The one caring for the sheep must fill a large tank with these liquids and dip the sheep into the tank to kill the louse. The chemicals are needed since the louse may be able to survive one to two days underwater.
A female louse lays 1 to 2 eggs every three days, up to 100 eggs. She attaches the eggs to the wool with fast-drying glue. They hatch about 9 days later. When ready to hatch, the young make small holes in their shells near their heads and breathe in air. They release this air from their abdomens into the lower parts of their shells and build pressure beneath their bodies. When the pressure reaches a certain level, the young pop from their shells with steeple-shaped, eggshell caps still on their heads. For three to four weeks, the young molt, or shed their skins, three times before becoming adults. The average time from egg to adult is 35 days. Adult lice may live for up to 8 weeks.
One of the two dog lice (Trichodectes canis) may infect sheep and is sometimes called a sheep louse. This species of lice may carry the larvae of the tapeworm Dipylidium caninum. This parasitic worm infects the intestines of the sheep and robs nourishment from them.
Bibliography
Ketzis, Jennifer K. "Lice in Sheep and Goats." MSD Manual, 2023, www.msdvetmanual.com/integumentary-system/lice/lice-in-sheep-and-goats. Accessed 1 May 2024.
"Lice in Sheep." NADIS, clients.nadis.org.uk/planner-articles/lice-in-sheep. Accessed 1 May 2024.
"Sheep Lice Spread and Detection." Department of Primary Industries and Regional Development's Agriculture and Food, www.agric.wa.gov.au/livestock-parasites/sheep-lice-spread-and-detection. Accessed 1 May 2024.