Introduction
Grey-black hump-backed flies, 5 mm long and found in North and South America that are external parasites of birds and mammals. The flies transmit leucocytozoonosis and also a filarial parasite in ducks. The condition tends to occur near to rapidly flowing streams, although these insects can travel up to 15 miles. Eggs and larvae survive through the winter to cause new infestations in the following year.
Signs
- Anaemia in young birds.
- Swarms of flies.
Post-mortem lesions
- Anaemia.
Diagnosis
Anaemia, season, local history.
Treatment
Treatment is difficult.
Prevention
Similar measures as for mosquito control. Biological control using a strain of Bacillus thuringensis has had some success and is preferable to insecticides. Weekly treatments are required.