1930 ] 
Notes on Hippoboscidx 
305 
are far from satisfactory. 1 None of the species appear to 
have become naturalized in the New World, where their 
occurrence is very accidental. 
With one exception, the species of Hippobosca are ecto- 
parasites of mammals, mainly of Ungulates and Carnivora. 
H. struthionis, however, is a normal parasite of the ostrich. 
Since the Ungulates and Carnivora were more numerous 
and more widely distributed in Mesozoic times than nowa- 
days, it is safe to assume that Hippobosca has had a long 
geological past and may have been at one time cosmopoli- 
tan. The few living species are perhaps only the rem- 
nants of a large group of parasitic flies, which may have 
been as numerous in species as the living Hippoboscidse 
of birds. 
The Hippoboscse are fairly good fliers. The gravid female 
leaves the host and deposits the full-grown larva in cracks 
of walls, in holes of trees, or on the ground. Patton, for 
instance, observed a female of H. capensis leave a dog, fly 
onto a wall and, after running along it, rapidly disappear 
into a crack. The fly remained there a few minutes; as 
it emerged, it was caught, and, on examining the crack, a 
larva was found a little distance inside (Patton and Evans, 
1929, “Insects, Ticks, etc., of Medical and Veterinary Im- 
portance,”!, p. 404). 2 
Host specificity is not very pronounced among the Hip- 
poboscidse which retain the wings throughout adult life, 
and this statement applies particularly to Hippobosca. Only 
the species of the ostrich seems to be restricted to a single 
host-species. H. fulva, H. hirsuta and H. camelina also 
have a narrow range of normal hosts. The other species 
have nowadays a variety of usual hosts; but in some cases 
this may be an artificial condition, due to the influence of 
man. Spreading of certain species by man beyond their 
1 There is a voluminous literature dealing with the ancestors of 
domestic animals. After consulting a number of publications, I have 
found what appears to be the most reliable information in Keller, 
Conrad, 1902. “Die Abstammung der altesten Haustiere,” (Zurich), 
232 pp. 
2 1 have not found any evidence that the puparia of Hippobosca 
are ever placed among the fur or feathers of the host, as Theobald 
(1906, 2d Rept. Wellcome Res. Lab. Khartoum, p. 92) has claimed. 
