130 



Sambon (L, W.). Observations on the Life-History of Dermatobia 



hominis (Linnaeus Jun., 1781). — Rep. Advisory Committee, Trop. 



Dis. Res. Fund for 1914, London, 1915. Appendix vii, pp. 119- 



150, 4 figs. 



Information as to the bionomics of Dermatobia liominis, L., obtained 



in the course of a journey in Colombia, British Guiana and Trinidad, 



is detailed. The larva of this fly is a common parasite of man in certain 



regions of Intertropical America. It has been recorded at various 



times under the names, Cuterebra tioxialis, Goudot, 1845, and 



Dermatobia cyaniventris, Macquart, 1843. A hst of 10 synonyms of 



this species is given, as well as a full hst of EngHsh, Spanish and 



Portuguese popular names, some of which also apply to the larva of 



Chrysomyia macellaria. D. hominis is a neotropical Oestrid, ranging 



throughout tropical America. It chiefly occurs in the wooded 



tracts of the coastal lowlands and river valleys. The habitat is 



associated with a warm temperature, a certain amount of surface 



water, and forest vegetation. The presence of large herds of cattle 



is an important element in the distribution, prevalence, and spread 



of this Oestrid, but is by no means essential. It attacks man and 



domesticated dogs in virgin forests far removed from cattle-grazing 



grounds, where local wild animals must serve as hosts for the parasitic 



larval stage. A more important factor in distribution is no doubt 



the insect associate which appears to be frequently employed by the 



Oestrid for the conveyance of its progeny to a suitable vertebrate 



host. This nurse, or carrier, is as a rule a woodland breeding mosquito 



of the genus Janthinosoma. Hitherto the few individuals carrying 



Dermatobia eggs which have been determined, belong to the species 



J . I'Utzi, which occurs in damp woods and shady river sides, but probably 



other species with a similar distribution may also be concerned. 



Imported cases of cutaneous myiasis due to Dermatobia hominis have 



been observed from time to time in New Orleans and other towns, 



but so far it has not been reported as indigenous from any part 



of the United States. It is not found on the so-cafled Mexican 



plateau, made up of irregular uplands bordered by the two converging 



sierras, but is more or less plentiful in the warm marshy plains 



below, from which it was reported as far back as 1653. It is 



common in man, dogs and cattle on the low-lying coastlands of 



Central America, and labourers in the Panama Canal suffering from 



its attacks are frequently admitted to hospital in New Orleans. Cattle 



suffer seriously from it in the river valleys and coast lands of Colombia 



and on the low plains east of the Andes ; it swarms on the borders 



of the great forests, as well as in places where both wood and prairie 



land are present. It is common in Venezuela and well known in 



Trinidad, but is thought to be absent from the Leeward and Windward 



Islands, as well from the Greater Antilles. In the Guianas and Brazil 



D. hominis is widely spread and very common. The fly is abundant 



in Peru, but there is no information as to Paraguay, Argentina, Chili 



and Ecuador. Cattle are so seriously attacked that the so-called 



" Rio hides " are of little commercial value. Horses are also attacked, 



and mules are certainly not immune, as the muleteers in Guatemala 



squeeze out the warbles and treat the sore with undiluted creolin 



which they carry for the purpose. The same method is used by the 



land-owners, but it is possible that Chrysomyia macellaria is also largely 



