Paid Advertisement
 

< Back to Other Articles In This Category

Understand lice to kill them or keep them out

by Deb Maxwell, Operations Manager, ParaBoss

When trying to kill lice or keep them out it pays to know a little bit about them. Here are 5 questions to test your knowledge about lice

Further information can be found at: Biology of sheep lice.

Quiz questions  (Answers  are below the photo.)

1. What are the 3 types of lice found on Australian sheep?

2. How long can it take for a lice to complete its lifecycle, that is from an egg, to an adult ready to lay eggs?

3. Does transfer of lice from sheep to sheep occur more slowly or more rapidly when the wool is shorter?

4. Do lice easily transfer between sheep in adjacent paddocks?

5. When a flock is infested with lice for some time, will all sheep become infested?


Female louse. Source: Peter James.
Female louse. Source: Peter James.

1. What are the 3 types of lice found on Australian sheep?

  • The sheep body louse, Bovicola ovis, is found across the woolled areas of the sheep.
  • The face louse, Linognathus ovillus, occurs mainly on or close to the face.
  • The foot louse, Linognathus pedalis, is found on the legs and on the scrotum in rams. 

2. How long can it take for a lice to complete its lifecycle, that is from an egg, to an adult ready to lay eggs?

  • 34-36 days.

3. Does transfer of lice from sheep to sheep occur more slowly or more rapidly when the wool is shorter?

  • Transfer occurs more quickly when sheep have short wool than when the wool is longerSignificant spread between sheep can occur in counting out pens after shearing.

4. Do lice easily transfer between sheep in adjacent paddocks?

  • Spread of lice between mobs in adjacent paddocks does not occur readily if sheep do not get through fences. In a South Australian study it was not until 64 weeks after the introduction of two lousy sheep to a clean mob that lice spread to sheep in an adjacent paddock (Cleland et al. 1989). However, one can imagine scenarios in which spread across fences occurs more quickly than this, for example where sheep camps in adjacent paddocks are close to each other or where sheep share a common watering point and may come into contact while drinking. Wool caught on fences is unlikely to be a source of infestation as most lice drop out of this wool within a few hours (Crawford et al. 2001).

5. When a flock is infested with lice for some time, will all sheep become infested?

  • Individual sheep vary in susceptibility. Some sheep do not become infested despite repeated challenge.

Further information can be found at: Biology of sheep lice.