70 



- 



climates the species of Tabanus, like those of other genera of 

 Tabanidse, pass the winter in this state. The pupce, which may be 

 looked for in damp earth near the margin of water, are also of the 

 normal type, with a pair of large, ear-shaped, prothoracic spiracles, 

 a circlet of spines near the hind margin of each abdominal segment, 

 and six stout teeth at the apex of the abdomen ; by means of these 

 spines and teeth the pupae work their way up to the surface of the 

 ground just before the adults emerge. The preliminary stages of 

 Tabanus biguttatus, Wied. (Plate VI., figs. 44, 45), have recently 

 been figured and described by Mr. H. H. King, of the Wellcome 

 Research Laboratories, Gordon Memorial College, Khartoum.* 



Although there is as yet no evidence that any 



Tabanus species of Tabanus is a regular disseminator of 



and Disease, any micro-organism pathogenic to man, the 



results of recent experimental work by the 



brothers Sergent in North Africa, coupled with those obtained by 



Rogers and others elsewhere,f tend to show that it is impossible to 



ignore the importance of these flies as direct transmitters of 



trypanosomiases affecting domestic animals. It may even be 



that something more than direct transmission occasionally 



s 



takes place, since in Algeria Drs. Edmond and Etienne Sergent 

 on one occasion succeeded in transmitting the Trypanosome 

 of el debab (a camel-disease which occurs from Morocco to 

 Syria, and more than decimates Algerian dromedaries) by 

 means of Tabanus (Atylotus) tomentosus, Macq., when there 

 was an interval of twenty- two hours between the bites. The 

 Drs. Sergent, who also performed successful direct-transmission 

 experiments with the parasite of el debab, using Tabanus (Atylotus) 



* See pp. 88, 90. 



f Cf. L. Rogers, M.D.,'*The Transmission of the Trypanosoma Evansi by Horse-flies," 

 etc. : Proceedings of the Royal Society of London, Vol. LXVTIL, pp. 163-170 

 (1901). According to Bagshawe (Sleeping Sickness Bureau, Bulletin No. 5, March, 

 1909, p. 188), Rogers's results have recently been confirmed by Fraser and Symonds 

 in the Federated Malay States. It is interesting to note that " with an emulsion of 

 a species of Tabanus, made twenty-four hours after feeding [on an infected animal], 

 two guinea-pigs were infected " (cf. Fraser, H., M.D., and Symonds, S. L., " Surra 

 in the Federated Malay States. With a Note on the Distribution of certain species 

 of Biting Flies in the Federated Malay States, by H. C. Pratt, Government 

 Entomologist," Studies from the Institute for Medical Research, Federated Malay 

 States, No. 9, 1908) (Singapore: Kelly & Walsh, Ltd.). 



