Trombicula autumnalis

Also known as:

The harvest mite

Trombicula mite bites Tim Vickers 2008, wikimedia commons

Trombicula autumnalis are surface mites. They cause parasitic skin infestation and will parasitise any animal, including humans as they are non-species specific. The mite numbers are highest in late summer in temperate climates and are therefore constant all year in tropical regions.

Identification

The mites are bright orange in colour and hairy. They have six legs and no spiracles. They breath through their cuticle

Lifecycle

The lifecycle of Trombicula autumnalis mites lasts around 50 to 70 days. The nymphal and adult stages are free-living in the soil. The female mites become more active in the spring and lay their eggs onto the vegetation. Only the larval stage is parasitic to the host.

Pathogenesis

The larvae insert their mouthparts into the host's skin and inject cytolytic enzymes. They then feed on partly digested host tissue causing irritation and potentially a hypersensitivity reaction. The Mites are mainly found on the head, ears and flanks of pets and can be found on the face and limbs of grazing animals, depending upon the host height.

Control

Trombicula autumnalis mites are very difficult to control. The main method of control is to try to restrict the access of animals to 'hot-spot' areas.

Treatment

Apply Fipronil spray to affected areas.