CHAP. XIV. FAMILIES OF DIPTERA. 



89 



through the first basal and first posterior cells. These insects 

 fly very rapidly, and sometimes balance themselves on the 

 wing, like a hawk; they are usually banded with yellow, 

 somewhat like a wasp. They feed on the nectar of flowers. 

 The larva? of a few species are aquatic, but the greater number 



are terrestrial and feed on plant-lice ; one species, however, 



\fc v 



Fig. 230. 



the Narcissus-fly, is said to live in the soil, around decayed 

 bulbs. The pupae are coarctate, and the slender anterior end 

 of the larva becomes the thickened end in the pupa. (See 

 Figs. 231 and 232.) 



Fig. 231. 



Fig. 232. 



BOT-FLIES (JEstridse). These flies usually have very small 

 antennae, which are situated in rounded pits or depressions ; 

 the mouth-parts are small, and often rudimentary , the body 



