ENTOMOLOGY

DISEASES TRANSMITTED BY BLOODSUCKING FLIES !!17they assume the "salivary trypanosome form" and are then capable ofinfecting any susceptible animal (Hindle).CasteUanella rhodesienae (Stephens and Fantham) Chalmers, causeof RHODESIAN SLEEPING SICKNESS of man, is carried by GlossinamorsitOlTUl Westwood, G. palpalis Robineau-Desvoidy, and G. brevipalpisN ewstead. The insect becomes infective after an incubation period ofabout 14 days and is infective throughout the remainder of its life. Thelife cycle is not completely worked out, but it is known that the trypanosomesfirst become established in the intestines and later invade thesalivary' glands (Hindle).Castellanella soudam.ense (Laveran) Chalmers, cause of TAHAGA ofdromedaries in Sudan, EL DE DAB of dromedaries in Algeria, andZOUSF AN A of horses in Sud Oranais, has been experimentally transmittedby Stomoxys calcitrOlTUl Linnaeu~ S. nigra Macquart, Atylotusnemoralis Meigen, and A. tomrmtosus Macquart ..Duttonella caprae (Kleine) Chalmers, cause of an African goat Trypanosomiasis,is transmitted by Glossina brevipalpis Newstead and G.morsitOlTUl Westwood.Dutt"onella cazalboui (Laveran) Chalmers, cause of SOUMA, anAfrican anim~l trypanosomiasis, is principally carried by the tsetse fliesGlossina palpalis Robineau-Desvoidy, G. longipalpis Wiedemann, G. morsitansWestwood, and G. tachinoides Westwood, but may also be transmittedby. Stomoxys calcitrans Linnaeus, Tabanus biguttatus Wiedemann,and T. taeniatU8' Macquart, apd ·possibly Stomoxys nigra Macquart.Development of the organism is restricted to the proboscis ofthe tsetse fly, the flagellates never multiplying in any other part ofthe alimentary canal. They may change in the proboscis into leptomonador crithidial forms, attach'to the walls of the labrum and undergorapid multiplication. Under the influence of the salivary secretionsome of these fixed flagellates develop into small, actively motile trypanosomesclosely resembling the blood forms. This becomes infectivefrom six to ten or more days after ingestion of the parasites.Duttonella cazalboui pigritia (Van Saceghem), cause of ZAMBIANSOUMA of cattle, is carried by Haematopota perturbans according toYan Saceghem who' found the organ~sm in the intestinal tract of fliestaken on infected animals.Duttonella congolense (Broden) Chalmers, cause of GAMBIANHORSE SICKNESS, is carried by Glossina morsitans and possibly byG. palpalis and species of Glossina, Tabanus and Stomoxys. The variousforms of the parasite have been demonstrated in the alimentary canalof G. morsitfll1l,8 !!3 days after ingestion.Duttonella nanum (Laveran) Chalmers, cause of a fatal BOVINETRYPANOSOMIASIS of Africa, is carried by Glossina palpalis, and