Introduction
| Also known as: | Midges |
| The most important veterinary species | Culicoides |
This parasite is found worldwide and attacks a wide variety of animals and also attacks humans.
Recognition
Small flies 2-5mm long with a dark colouring. They have a characteristic arched thorax giving a 'hump-backed' appearance. The wings are mottled.
Life cycle
Eggsare laid on to plants near water and the larvae fall into water and pupate. The life cycle takes 6-12 months to complete in temperate climates but is only 1 month in tropical climates.
Pathogenesis
Culicoides is most active in late afternoon and early evening. Bites are painful and irritating. Only females suck blood.
A bite causes 'Sweet itch', a culicoides hypersensitivity reaction
- Seasonally occurring allergic dermatitis of horses
- Affects the base of the tail and the withers
- Intermediate-type hypersensitivity reaction to the midge saliva
The midge is a vector for several viruses:
It is also a vector for several parasites:
- Onchocerca spp. in cattle and horses
- Protozoal skin infections
- Causes skin infections
- Onchocerciasis
- Involved in cutaneous habronemiasis
- Involved in stephanofilariasis
Control
This is difficult due to the extensive breeding sites but can include drainage of breeding sites, stabling horses at peak midge activity times e.g. from late afternoon to early morning, the use of insecticide fly strips in stables and topical fly repellent.