Trombicula autumnalis

• Causes parasitic skin infestation

• Also called the harvest mite

• Not host-specific
  • Will parasitise any animal, including humans

• Only the larval stage is parasitic
  • Nymphal and adult stages are free-living in the soil

• Mite numbers are highest in late summer in temperate climates
  • Mite numbers are constant all year in tropical regions

Recognition

• Six legs

• Bright orange in colour

• Hairy

• No spiracles
  • Breath through cuticle

Pathogenesis

• Larvae insert mouthparts into skin and inject cytolytic enzymes

• Feed on partly digested host tissue

• Causes irritation

• Can cause a hypersensitivity reaction

• Mites found on head, ears and flanks of pets

• Mites found on face and limbs of grazing animals (depending upon host height)

Control

• Very difficult; try to restrict access of animals to 'hot-spot' areas

Treatment

• Fipronil spray applied to affected areas