DIPTERA 



851 



The larvse vary greatly in form and habits. Some prey upon plant 

 lice, and are often found in the midst of colonies of these insects ; some 

 feed in the stems of plants and in bulbs ; others feed on decaying vege- 

 table matter, and live in rotten wood, in mud and in water; and others 

 live in ordure or in decomposing animal remains. Some are found in 

 the nests of ants ; and some in the nests of bumblebees and wasps. 



Among the common representatives of this family there is one 

 that so closely resembles a male honey-bee as to be often mistaken 

 for it. This is the Drone-fly, Eristalis tenax. It is common about 



/?. R^^^ /?4 + » 



Fig. 1 1 04. — Wxngoi Eristalis. 



flowers. The larva lives in foul water, where it feeds on decaying 

 vegetable matter; it is of the form known as "rat-tailed," which is 

 described below. 



The larvae of the genus Volucella live as scavengers in the nests 

 of bumblebees and of wasps (Vespa). Some of the species in the 

 adult state very closely resemble bumblebees. 



The larvag of the genus Mtcrodon are hemispherical, slug-like 

 creatures (Fig. 1105), which resemble mollusks more than ordinary 

 maggots; they are common in ants' nests. 



The larvse of several species that live in water as well as some 

 that live in rotten wood are Icnown as rat-tailed maggots on account 

 of the long, tail-like, appendage, with which the hind end of the body 

 is furnished. This is a tube, \\ke that of a diver, which enables the 

 insect to obtain air when its body is submerged beneath several inches 

 of water or decaying matter. This 

 tube being telescopic can be length- 

 ened or shortened as the insect may 

 need it ; and at its tip there is a ros- 

 ette of hairs, which, floating on the 

 surface of the water, keeps the tip 

 Fig.i 10^-Microdon. adult from being submerged. The larva 

 and larva. has on the ventral side of its body Fig. 11 06.-- 



several pairs of tubercles armed with Syrphus. 

 spines, which serve as prolegs. 

 . Among the more common members of this family are the yellow- 

 banded species belonging to the genus Syrphus (Fig. 1 1 06) . The larvae 



