Melophagus ovinus (2)

Question 1

What are the hosts?

Answer 1

Sheep

Question 2

Describe adults

Answer 2

5-7 mm

Hairy and wingless

Short head

Broad, flattened, brownish thorax and abdomen

Mouthparts adapted for sucking blood

Question 3

Describe pupa

Answer 3

Ovoid

Dark brown

3-4 mm attached to wool

Question 4

Explain life cycle

Answer 4

Entire life cycle takes place on host

Heavy infestations - Autumn and winter

Female produces 1 egg which hatches inside her body

Female gives birth to mature larvae - adhere to wool

Pupate within 12 hours

3rd instar adheres to fleece
- Immobile larvae pupate (3-4 mm) and visible on fleece

Adults emerge in 3 weeks in summer, longer in winter

Producers mistake pupae for engorged ticks

Transmission by direct contact

Adults and pupae only live short periods off hosts

Question 5

What is the site of infestation?

Answer 5

Wool

Question 6

Describe the Pathogenesis

Answer 6

Keds suck blood

Heavy infestation
- Lead to loss of condition and anemia

Long-wooled breeds - susceptible

Irritation caused leads to animals biting/rubbing
- Results: Damage to fleece

Transmits Trypanosoma melophagium (non pathogenic in sheep)

Question 7

How do you diagnose?

Answer 7

Fly identification

Close inspection of damaged, dirty wool

Underlying skin reveals infestation

Unique appearance of wingless, hairy flies or pupae

Question 8

How do you treat and prevent?

Answer 8

Shearing removes many pupae/adults
- Shearing before lambing and subsequent treatment of eyes with
insecticides
- Control remaining keds - reduce possibility of lambs becoming
infested

Usually treated after shearing

Best results: insecticides with residual activity of 3-4+ weeks used

Treatments to control lice also control keds

Question 9

What are the common names?

Answer 9

Sheep ked

Sheep tick