The tail-switch louse of cattle is mainly a tropical species, but has been found in all mainland states of Australia, and is often found on Bos indicus type cattle. These lice are very similar in appearance to short nosed cattle lice.
The cattle tail louse can sometimes be spread from animal to animal or herd to herd by flies. The 3rd instar nymphs of the tail louse frequently migrate to the backs and shoulders of animals. There they can climb onto flies frequenting the animal and be carried to new hosts.
Sucking louse, fine mouthparts puncture the skin to feed on cattle blood.
This one of the larger species of cattle lice with the adults up to 4.5 mm in length (Figure 1)
Most eggs are laid in the tail switch (brush) and in severe infestations, high numbers of eggs can be seen matting the hair in this area.
Adult lice are mostly found on the tail only (Figure 2). Heavy infestations may extend to dewlap or surround the eyes. Nymphs are commonly seen feeding in the softer skin around anus and vulva and sometimes around the eyes.
The incubation period of the eggs of this species is 9-40 days depending on temperature, and the complete life cycle from egg to adult can be in as few as 25 days.
Since tail-switch louse eggs can hatch up to 40 days after oviposition, treatments must be reapplied at 3 week intervals to attain good control.