Illustrations of African blood-sucking flies other than mosquitoes and tsetse-flies / by Ernest Edward Austen.

  • Ernest Edward Austen
Date:
1909
Catalogue details

Licence: Public Domain Mark

Credit: Illustrations of African blood-sucking flies other than mosquitoes and tsetse-flies / by Ernest Edward Austen. Source: Wellcome Collection.

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    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 pupse 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 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. I Cf. L. Rogers, M.D.,“The Transmission of the Trypanosoma Evansi by Horse-flies,” etc. : Proceedings of the Royal Society of London, Vol. LXVIII., 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.).