Mallophaga (biting lice)

Fast facts about Mallophaga (biting lice)

Body flattened, wingless, with poorly-developed small eyes.
Chewing mouthparts.
Head usually broader than long.
All ectoparasitic, upon birds and sometimes mammals at all stages.
At least 3000 species worldwide, 700 in Europe and 500 recorded in Britain.
Hemimetabolous. Biting lice do not infect man.

Biting lice body pattern

As can be seen in the bird louse on the right the antennae are small. Usually there are only 3 - 5 segments, and the whole thing may be hidden in a groove in the head.

The legs are usually adapted to cling firmly to the host, and end in two claws.

Louse body shape can vary according to the location on the body the louse specialises in. Those inhabiting the main feathers are usually long, whereas those feeding near the neck tend to be rounder.

Size varies, but is usually less than 5 mm in length.

Biting lice feeding and ecology

Biting lice feed mainly on particles of feather, fur and skin. Some do feed on blood, but usually from existing wounds. There are some species that do bite through the skin of the host though.

Mallophaga (biting lice) life cycle

Females can lay 50 100 eggs which are cemented to the feathers or hair of the host. Nymphs and adults look alike. From egg to mature adult takes 3 - 4 weeks.

On the right is the dog biting louse, Trichodectes canis. It is brownish in colour, under 2 mm long and flattened from back to front. It can be seen with the naked eye, and is easily confused with the dog sucking louse, Linognathus setosus. The sucking louse has a narrower head and is greyish. However the treatment to get rid of them is easy and the same for both, Frontline combo or Advantix.

Lifecycle. The eggs are laid at the base of the hair to which they stick. In the nymphal stages the appearance is similar to the adult. The entire life cycle takes place on the dog's body.

The louse eats dead skin, and is most commonly found around the ears, neck along the backbone to the base of the tail. Lice are transferred between dogs by direct contact, and they will cause the dog to scratch.

On the right is Culutogaster sp. a feather louse. Adults are 1 - 2 mm long.