BIBIONIDAE SIMULIIDAE 



477 





Fig. 226. — Portion of integumeut of Bihio sp. Cam- 

 bridge, ^j, Intersegmental proces.ses ; s, spiracle. 



be spiracles. The food of Scatopse in the larval state 

 principally vegetable. The larva of Soatopse changes to 

 pupa inside the larval p 



skin ; the pupa is pro- 

 vided on the thorax with 

 two branched respiratory- 

 processes that project 

 outside the larval skin.^^ 

 Lucas has given an in- 

 teresting account of the 

 occurrence of the larva 

 oiBibio marci in enorm- 

 ous numbers at Paris ; 

 they lived together in 

 masses, there being ap- 

 parently some sort of 

 connection between the 

 individuals." In tlie following year the fly was almost equally 

 altuudant. 



Owing to the great numbers in which the species of Bibionidae 

 sometimes appear, these Insects have been supposed to be very 

 injurious. Careful inquiry has, however, generally exculpated 

 them as doers of any serious injury, though Dilophus fehrilis — a 

 so-called fever-fly — appears to be really injurious in this country 

 when it multiplies excessively, by eating the roots of the hop- 

 plant. 



Fam. 11. Simuliidae {Sand-fiies, Buffalo-gnats). — Small obese 

 flies with humped haek, rather short legs and hroad wings, loith short, 

 straight antennae destitute of setae ; jn-ohoscts not projecting. 

 There is only one genus, Simulium, of this family, but it is very 

 widely spread, and will probably prove to be nearly cosmo- 

 politan. Some of the species are notorious from their blood-suck- 

 ing habits, and in certain seasons multiply to an enormous extent, 

 alight in thousands on cattle, and induce a disease that produces 

 death in a few hours ; it is thought as the result of an instilled 

 poison. >S'. columhaczense has occasioned great losses amongst 

 the herds near the Danube ; in North America the Bufffdo- and 

 Tui'key-gnats attack a variety of mammals and birds. In Britain 



^ Pei-ris, iu A7171. Soc. ent. France (2) y. 1847, p. 37, pi. i. 

 - Ann. Soc. ent. France (5) i. 1871, Bull. p. Ixvii. 



