Last update: August 16, 2011 07:55:45 AM E-mail Print

 

Red louse is host specific

JPJ Joubert

 

This biting louse is a big problem for mohair producers. In the previous edition of the Angora Journal a few articles were published which gave information on the red louse problem. What follows is more interesting information on red lice.

 

Survival of red lice away from the Angora goat

At the Regional Veterinary Laboratory in Middelburg, a pilot trial was done which showed that adult red lice can survive away from the Angora goat for only 36 hours under optimum environmental conditions. During this trial, eggs kept under these conditions for 62 days only managed to hatch for the first five days.

 

Host preference of red lice

An adult Angora goat ewe was kept with an adult Boer goat ewe in a pen of ten by nine metres for seven months. Red lice on the Angora goat ewe never parasitised the Boer goat ewe and at the end of this period she had no lice on her skin.

 

 

Resistance of red lice to dips

During 1959 it was reported that the red louse of the Angora goat showed resistance to some of the dips available at that stage.

 

Initial effectiveness of dips

In the same year it was reported that diasinon at a 0,1 percent concentration gave protection for 32 weeks against the sheep red louse (Damalinia ovis).

 

Summary

The available information indicates that the red louse of the Angora goat can maintain itself only on the goat itself. Therefore, proper dipping of all the goats (with dunking of their heads) using the correct concentration of dip and a repeat dipping after 14 days, should be adequate to control red lice. Where resistance is suspected one of the combination dips should be used.

A survey on the extent of resistance of red lice of Angora goats to dip remedies, is planned for 1993.

 

Contribution by

Dr J P J Joubert, VRL,

Grootfontein

 

 

Published

Angora goat and mohair journal 35 (1)