THE MECHANICAL TRANSMISSION OF Trypanosoma evansi BY Haematobia minuta (DIPTERA: Mus c idae) AND Hippobosca camelina (DIPTERA: Hippobos c idae) FROM AN INFECTED CAMEL TO A MOUSE AND THE SURVIVAL OF TRYPANOSOMES IN FLY MOUTHPARTS AND GUT

Abstract

The role of Haematobia minuta Linnaeus and Hippobosca camelina Leach in the transmission of camel trypanosomiasis was assessed. In a preliminary survey, there were no trypa­ nosomes in the mouth parts or gut of the field collected, H. minuta and H. camelina, following dissections. H. minuta mechanically transmitted T. evansi from an infected camel to mice but H. camelina failed to do so. Results show that H. minuta may play just a minor role in the transmission of camel trypanosomiasis as no parasites were found in the mouth parts and gut of the field collected flies and the transmission rate was low. Although parasites survived in the gut of both flies for as long as thirty minutes, the sur­ vival of trypanosomes in the mouth parts of both flies was restrictive as far as mechanical transmission is concerned. H. camelina failed to transmit T. evansi experimentally and therefore its importance in the transmission of camel trypanosomiasis in Northern Kenya was ruled out, unless by regurgitation. Sub−inoculated homogenates of flies pre­ viously fed on an infected camel were infective to Balb C mice but the significance of this in relation to mechanical transmission in nature remains unclear