Effect on the host

EFFECT ON THE HOST- BITING MIDGES

Direct

  • They cause very painful bites and are a source of irritation to man and animals
  • C. robertsi is known to cause an allergic dermatitis in horses in Queensland, Australia
  • The condition is called as Queensland itch, sweet itch, sweat itch or summer dermatitis
  • The withers and base of the tail of the horse which are bitten by the fly are mainly affected
  • There is an immediate hypersentitivity reaction and intense pruritis is observed in affected horses
  • Further, there is loss of hair and hyperpigmentation 
  • The condition resolves by itself

Indirect (vector potentiality)

  • They act as vectors for,
    • Blue tongue virus in sheep
    • African Horse sickness virus
    • Bovine ephemeral fever virus
    • Eastern equine encephalitis virus
    • Leucocytozoon caulleryi in fowls
    • Haemoproteus nethionis in ducks, geese etc.
  • They also act as intermediate host for filarid nematodes like Onchocerca cervicalis in horses and O. gibsoni in cattle
Last modified: Thursday, 24 June 2010, 5:37 AM