SOME SIAMESE TABANIDAE. 445 



Of this species, the type of which is from India (North Kanara), the British 

 Museum (Natural History) possesses a 9 from Bangkok, collected in 1898 by Major 

 S. S. Flower, O.B.E. Apart from this specimen and the typical series, the only 

 examples of the species as yet contained in the National Collection are from South 

 Malabar (South-west India, a little to the south of the locality where the type and 

 paratypes were obtained). 



8. Tabanus striatus, Fabr. 



Tabanits striatus, Fabricius, Entomologia Systematica, iv, p. 371 (1794). 



Tabanus partitas, Walk., Journ. Proc. Linn. Soc, i, p. 9 (1857). 



One (^, Bangkok, 30.viii.l921, caught in donor's house at night, attracted by 

 electric light ; only specimen seen : one $, Chiengmai, 7.v. 1921, on donor's verandah 

 at dusk — a solitary specimen, which did not attack. Two $2 of this species from 

 Bangkok, taken respectively in 1907 {Dr. P. G. Woolley) and November 1919 {F.J. 

 Godfrey), were previously included in the Museum collection. 



The distribution of T. striatus is very wide, its range, as shown by material in the 

 National Collection, extending right across the Oriental Region, from North-western 

 and Western India (Kohat and Bombay) to Hong Kong and the Phihppine Islands, 

 and including the Federated Malay States, Singapore, Sumatra and Java. 



According to Mitzmain,* who studied the bionomics of this species in the Philip- 

 pines, and also in the same year (1913) demonstrated experimentally its capacity to 

 act as a mechanical transmitter of surra,! T. striatus is " the most prevalent horsefly " 

 in the Philippine Archipelago, where, although also attacking cattle and horses, it 

 appears to prey by preference on the carabao (buffalo). As regards human beings, 

 the author referred to writes : " During over two years of personal observation, this 

 fly has never been known to annoy man in the Philippine Islands." 



In the dried (pinned) condition, at any rate, apart from their usually darker appear- 

 ance, specimens of T. striatus, especially when the median abdominal stripe is not 

 obliterated on the second tergite, are sometimes liable to be mistaken for examples 

 of T. teneits. Walk., of which T. hilaris, Walk. (Insecta Saundersiana, i, Diptera, pt. i, 

 p. 49 (1850)), and T. megalops, Walk. (List Dipt. Ins. in coll. Brit. Mus., v, Suppl. i' 

 p. 247 (1854)) are synonyms. So far as it is at present possible to judge, the range of 

 T. tenens is much more restricted than that of T. striatus, though the evidence afforded 

 by the series of specimens in the Bri+ish Museum (Natural History) shows that this 

 species is common in parts of India {e.g. Madras), and also occurs in Ceylon and Java. 

 In the t^ sex, excluding differences due to colour, T. striatus, Fabr., is distinguishable 

 from T. tenens, Walk., by the cUstal margin of the penultimate segment of the front 

 tarsi being more deeply notched. In its typical form, as represented by specimens from 

 Hong Kong, the $ of f. striatus may be distinguished from that of T'. tenens, inter alia, 

 by the shape of the lower frontal callus, which is less elongate, i.e., broader in pro- 

 portion to its length ; by the shape of the third and fourth segments of the front tarsi, 

 the sides of these segments when the front legs are viewed from above appearing 

 straighter ; and by the legs in general being darker — the femora infuscated, and the 

 front tarsi deep black instead of ferruginous or brownish. 



Miss G. Ricardo, in her " Revision of the Species of Tabanus from the Oriental 

 Region, "§ involves the identity and synonymy of Tabanus striatus in hopeless 

 confusion, since T. tenens. Walk., and T. megalops, Walk., are included among the 



* Cf. M. B. Mitzmain, " The Biology of Tabanus striatus Fabricus [sic], the Horsefly of the 

 Philippines " : Philippine Journ. Sci., viii, no. 3, Sec. B, Tropical Medicine, pp. 197-221. pis. I-VII 

 (June 1913). 



t Cf. M. B. Mitzmain, " The Mechanical Transmission of Surra by Tabanus striatus Fabricus " 

 [sic] : ibid., pp. 223-229 (June 1913). 



§ Cf. G. Ricardo, " A Revision of the Species of Tabanus from the Oriental Region, including 

 Notes on Species from Surrounding Countries " ; Rec. Ind. Mus., iv, pp. 150, lo3 (1911). 

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