Some effects of uninfected laboratory-reared tsetses (Glossina morsitans morsitans westw.) (diptera: glossinidae) on host-rabbits.

Rabbits (Flemish giant x French lop-eared) exposed to 300 to 500 tsetses (Glossina morsitans morsitans Westw.) a day, 2 or 3 days a week, did not show significant differences from littermates receiving no exposure, with respect to weight changes, haematocrits, red and white blood cell counts or whole blood clotting times. In other rabbits, the same daily exposure, 6 days a week, resulted in sharp decreases in haematocrit levels and in some, changes in weights, but no change in citrated plasma thrombin times. Rabbit haematocrit levels correlated negatively with estimated weekly blood loss. Weights and haematocrits of most rabbits exposed to 1,200 to 1,500 flies on a single occasion were not affected. However, following heavy exposure, ears were cold and blood letting difficult, indicating the possibility of arteriolar vasoconstriction.