142 



commonest and most widely distributed are Stomoxys nigra, Macq. 

 (Plate XIII., fig. 101), and the almost cosmopolitan S. calcitrans, 

 Linn. (Plate XIII., fig. 102). The species of Stomoxys are small 

 greyish, brownish- or blackish-grey, or blackish flies, about 5.5 to 

 7 mm. in length, in the case of African species, with a slender, 

 shining black, chitinous proboscis projecting horizontally from 

 beneath and in front of the head. Except in the darker species, 

 the thorax is marked with clove-brown or blackish longitudinal 

 stripes, and the abdomen bears brown or blackish spots or transverse 

 bands. The sexes can be distinguished by the eyes being much 

 closer together in the male than in the female ; in the case of 8. 

 omega, Newstead (Plate XIII., fig. 96), a further sexual difference 

 is constituted by a remarkable series of curled hairs on the inside 

 of the front tarsi of the male (see p. 158). 



Stomoxys attacks human beings as well as animals, and is capable 

 of infiicting a jDainful bite, at least a third of the proboscis being 

 driven into the skin. 



There can be little doubt that the life-history 

 Life-history, of all species is similar to that of S. calcitrans 



(see pp. 146-148), the metamorphoses of which 

 have as yet alone been studied. 



The available evidence on this subject will be 



Stomoxys found fully detailed in the notes on S. calcitrans 



and Disease, and S. nigra, which would appear to be the only 



species with which experiments have yet been 

 made, and to one or other of which all observations refer. 



Stomoxys calcitrans, Linnaeus. 



Systema Naturae, Ed. X., T. I., p. 604 [Conops^ (1758) : Fauna 

 8uecica, Ed. II., p. 467, 1900 [Conops] (1761). 



Plate XIIL, fig. 102. 



Stomoxys calcitrans, a common and well-known pest of human 

 beings and domestic animals in Europe, and S. nigra, Macq.,* 

 * See below, p. 153, and Plate XIII., Fig. 101. 



