[Trypanosomes of Estrildidae birds. II. Biological studies]

Studies on the biology of 4 Trypanosomes of Estrildidae birds described in a previous paper (Chandenier et al., 1988) are related. In Culicoides nubeculosus, the complete development is achieved in 7 days. After a phase of intense multiplication of amastigotes in the gut, infective trypomastigotes appear. In cultures, infective stages are obtained in 13 days. Transmission to clean birds was attempted: in two out of 8 attempts, a satisfactory level of parasitaemia is obtained. Surprisingly Trypanosomes infecting the new birds are unable to develop further in cultures or in Culicoides. The most likely hypothesis is the lack of a factor allowing the Trypanosomes to mature.