478 



OTHER HI.ODD-SUCKING FLIES 



Blackflies or Buffalo Gnats 



Fio. 219. 

 pecuaram . 



Blackfly, Sinndiuin 

 X 7. (After Riley.) 



General Account. — The blackflies, as annoyers of domestic 

 animals and man. are among the most important of insect pests. 



The females are most insatiable blood- 

 suckers, and have been known to at- 

 tack cattle in such swarms as to kill 

 them; a Himalayan species, accord- 

 ing to Alcock, has been said to kill 

 even human beings in the same way. 

 These small insects, which constitute 

 the family Simuliida% are quite unlike 

 the other flies of the group to which 

 they belong. Instead of the usual 

 slender, long-legged, midgelike flies of 

 this group w(> liave in the blackflies 

 small, robust, humpbacked creatures 

 with short legs and broad wings, rather 

 resembling, in a general wa}', minia- 

 ture houseflies (Fig. 219). The an- 

 tennae are composed of 11 segments, but they are shoi't and 

 stock}', and have no hairs at the 

 joints. The proboscis in the 

 female is short l)ut heavy and 

 powerful, while in the male it 

 is poorly developed. The mouth- 

 j)arts are made up of \\\v same 

 l^arts as in mosquitoes, but are 

 dagger-like instead of needle- 

 like (see Fig. 220). Most of the 

 northern species are black in 

 color, whence their name, l)ut 

 some of the species are red- 

 dish brown or yellowish, and 

 they may be variously striped 

 and marked. The wings aic 

 either clear or of a grayish or 

 heavy veins near the anterior margin often distinctively 

 colored. Some of the species are not over one nun. i,^r, of 



hyp.-' lofbel. 



Fic. 220. Mou(hi)art.s nf bljickfly, 

 Simulium; ant., aiitcniia; cp., opipliar- 

 xiix: li.\|i., li\ |)(ii)harynx; lal)., lal^iuin; 

 l.'ilx'l., lalx'lliiin; inaiul., Miatidihle; 

 max., maxilla; max. p., maxillary pal- 

 pus. (.\flcr .\lc()rk.) 



vellowish color with the few 



