454 



THE STUDY OF INSECTS. 



In this family the third segment of the antenna is ringed 

 (Figs. 537, 538) and is never furnished with a distinct style 



or bristle. The wing-veins (Fig. 539) 

 are evenly distributed over the wing, 

 as the branches of vein III are not 

 crowded together as in the follow- 

 ing family ; the costal vein extends 

 completely around the wing ; the 

 alulets are large. 



The flight of these flies is very 

 powerful ; they are able to outstrip 

 the swiftest horse. The males feed 

 on the nectar of flowers and on 

 The mouth-parts of the 

 female are fitted for piercing the 

 skin and sucking the blood of men and quadrupeds ; the 



FIG. 537. 



Antenna of 



Tabanus. 



FIG. 538. 



Antenna of sWCCt Sap. 



(.hrysops. 



FIG. 539. Wing of Tabamis. 



females, however, also feed on the sweets of plants when 

 they cannot obtain blood. 



The larvae are carnivorous ; many live in the earth ; others 

 live in water. They feed on various small animals; some 

 upon snails, others upon the larvae of insects. In most cases 

 they have a single pair of spiracles, which is situated at the 

 hind end of the body; some have a pair of spiracles at 

 each end of the body. The pupa is not enclosed in the 

 skin of the larva. 



