980 REPORT OF THE HARVARD AFRICAN EXPEDITION 
the opinion that tabanids are the usual carriers in open country, while Stomoxys 
1s Important in more densely settled localities. Donatien and Lestoquard ! 
also believe that the same Trypanosoma berberum is occasionally conveyed from 
camels to dogs by Stomoxys, but they have not shown this by experiments.’ 
According to Gutberlet,* Hymenolepis carioca (Magalhaes), one of the common 
tapeworms of domestic fowl, has the stable-fly, Stomoxys calcitrans (Linnaeus), 
as its intermediate host. He succeeded in infecting young chicks free of parasites 
and kept in insect-proof cages, by feeding them large numbers of adult S. calci- 
trans caught in the yards. 
G. F. Hill‘ in Australia has first shown that Habronema microstoma (Schnei- 
der), a nematode living as adult in the stomach of equines, has Stomoxys calci- 
trans (Linnaeus) as the normal intermediate host. The life-cycle of this parasite 
in the fly has been worked out more carefully in France by Roubaud and Des- 
cazeaux.’ Stomoxys becomes infected in the larval stage by eating eggs of the 
worm. The development of the embryos proceeds exclusively in the adipose 
tissue of the maggot and is similar to that of H. muscae (Carter) in the house-fly 
larvae. Many of the infected maggots die, but in those that reach the adult 
stage, the larvae of the nematode work their way to the proboscis of the fly. 
The presence of the parasites in the proboscis seems to render the flies unable 
to pierce the skin and suck blood in the regular way. It is therefore highly 
improbable that Habronema microstoma is inoculated into the body of the defin- 
itive host by the bite of infected flies. Most likely intestinal infection occurs 
directly when the vertebrate host swallows adult flies containing larvae of the 
parasite. 
Noé © believes that Stomoxys calcitrans (Linnaeus) is the intermediate host 
of Setaria labiato-papillosa (Alessandrini), a nematode of the blood of cattle and 
deer, but he has actually given no experimental proof that such is the case. He 
merely found, in Italy, three to four per cent of the adult Stomoxys infected with 
a Filaria, which he assumes is the larva of Setaria labiato-papillosa. This larval 
nematode was described many years ago, from the proboscis of S. calcitrans in 
Germany, as Filaria stomoxeos O. v. Linstow (1875, Arch. f. Naturgesch., X LI, 
Lp. 195, PI VE, fies. 20-22). 
Stomoxys is essentially a genus of the tropical and subtropical parts of the 
Old World, whence one species, S. calcitrans (Linnaeus), has been widely spread 
1 Donatien, A. and Lestoquard, F. 1923. ‘Le debab naturel du chien. Transmission par les 
stomoxes.’ Bull. Soc. Path. Exot., Paris, XVI, pp. 168-170. 
2 See also Austen’s remarks, on Stomoxys as a disease-carrier, in 1909, ‘Illustr. African Blood-Suck. 
Flies,’ pp. 148-153. 
3 Gutberlet, J. E. 1919. ‘On the life history of the chicken cestode, Hymenolepis carioca (Magal- 
haes).’ Jl. of Parasitology, V1, pp. 35-88, Pl. IV. 
4 Hill, G. F.1918. ‘Relationship of insects to parasitic diseases in stock.’ Proc. Roy. Soc. Victoria, 
(N-S.) SOC, pt. 1, pp. dl 207 Pls, I—VOnT, 
5 Roubaud, E. and Descazeaux, J. 1922. ‘Evolution de l’Habronema muscae Carter chez la mouche 
domestique et de I’ H. microstomum Schneider chez le stomoxe.’ Bull. Soc. Path. Exot., Paris, XV, 
pp. 572-574. 
1922. ‘Deuxiéme contribution 4 |’étude des mouches, dans leurs rapports avec |’évolution des 
Habronémes d’équidés.’ Loc. cit., XV, pp. 978-1001). 
é Nod, G. 1903. ‘Studt sul ciclo evolutivo della Filaria labiato-papillosa Alessandrini.’ Atti R. 
Accad. Lincei, Roma, Rendic. Cl. Sci. Fis. Mat. Nat., (5) XII, pt. 2, No. 9, pp. 887-3893. 
