About Mites, Signs, Impact and Biology of Mites

Mites belong to a large group of arthropods (animals with jointed legs) with four pairs of legs, the best known being the spiders and scorpions. Mites are generally tiny representatives of this group and include numerous free-living forms as well as some species that are parasites.

Mites are more closely related to ticks than lice, but the signs of mites can be confused with lice, hence they are grouped with lice in LiceBoss, rather than TickBoss.

Costs

Severe infestations of mites are uncommon, so mites are not considered economically important.

Signs

Severe mite infestations can cause similar signs to lice, that is, skin irritation causing rubbing and scratching. The first step in identifying mites is to eliminate the presence of lice. This can be done by looking for lice on the irritated skin (signs of lice) where the cattle cannot reach to groom. If no lice are found on thorough examination, mites may be present.

Signs of irritation from mites can be localised on particular parts of the body depending on the mite species, see below. Diagnosis will usually require microscopic examination of a skin scraping, generally carried out by veterinarians.

• The chorioptic mange mite can cause irritation and itching on the hindlegs, hindquarters, tail and udder, which can lead to loss of weight, reduced milk production and crusty scabs on the skin.
• The cattle follicle mite, while a normal inhabitant of cattle, can occasionally cause heavy infestations on stressed animals leading to skin nodules on the neck, shoulders and dewlap, which can downgrade hides.
• The cattle ear mite, even though widespread, only occasionally causes inflammation or infection in the ears leading to head shaking, ear rubbing, lack of coordination, facial paralysis and hearing loss.
• The scabies mite has not been reported on cattle in Australia; in other countries it can cause severe irritation leading to weight loss, skin damage under the neck, brisket, inner thighs and base of the tail, and occasionally death.
• The scab mite is exotic, that is it is not present in Australia, and causes extensive scabs on the skin across the body resulting in rubbing, hide damage, weight loss, reduced milk production and weakness. It is a notifiable disease.
• Chigger mites are rarely a problem, but heavy infestations can cause redness and itching.

Mite species

There are more than 20,000 species of mites in Australia. About 4,000 of these have been formally identified and named. Only a small number of these mite species are parasites of cattle, and they are rarely abundant enough to become significant veterinary pests. Some species of mites are important pests of cattle in other countries, but are not found in Australia. For example, the scab mite Psoroptes ovis is not present in Australia, but presents a significant biosecurity threat to Australian livestock industries, including the cattle industry. It has been listed as a notifiable disease by the Australian Government Department of Agriculture and Water Resources.

Species of mites associated with cattle.

• Chorioptic mange mite (Chorioptes bovis)
• Cattle follicle mite (Demodex bovis)
• Cattle ear mite (Raillietia auris)
• Scabies itch mite (Sarcoptes scabiei)
• Scab mite (Psoroptes ovis)*
• Chigger mites: Tea-tree itch mite (Eutrombicula samboni) and grass itch mite (Odontacarus australiensis)
• Other mites: Cattle nasal mite (Speleognathus australis), cattle itch mite (Psorergates bos), Mange mite (Chorioptes texanus)*

*These mite species are exotic, that is, they are not found in Australia.