216 HYMENOPTEKA. 



blackish dorsal stripe, may be found rolled up in a spiral on 

 the leaves of the elm, birch, linden and willow trees. When 

 disturbed it ejects a fluid from pores situated above the spira- 

 cles. It constructs a large tough parchment-like cocoon, and 

 the fly appears in the early summer. 



The genus Trichiosoma is recognized by its hairy body, and 

 the antennae have five joints preceding the three-jointed club. 

 T. triangulum Kirb3 r is found in British America and Colorado, 

 and a variety, T. bicolor Harris, on Mount Washington ; it is 

 black, except the tip of the abdomen, with the fourth and fifth 

 joints of the antennae piceous, and the thorax is covered with 

 ash-colored hair. 



In Abia the antennas are seven-jointed, with the club obtuse ; 

 the bocby is villose, the abdomen having a metallic silken hue. 

 The Abia caprifolii Norton (Fig. 145, larva) is very destruc- 

 tive to the Tartarian Honeysuckle, sometimes stripping the 



bush of its leaves during successive sea- 

 sons in Maine and Massachusetts. It 

 hatches out and begins its ravages very 

 soon after the leaves are out, eating cir- 

 cular holes in them. It lies curled up 

 on the leaf and when disturbed emits 

 drops of a watery fluid from the pores in 

 the sides of the body, and then falls to 

 .the ground. During the early part of 

 August it spins a pale yellowish silken 

 cocoon, but does not change to a pupa, 

 Mr. Riley states, until the following- 

 Fig. 145. spring. He describes the larva as being 

 common about Chicago ; that it is "bluish green on the back, 

 and yellow on the sides, which are pale near the spiracles, and 

 covered with small black dots. Between every segment is a 

 small, transverse, yellow band, with a black spot in the middle 

 and at each end. Head free, of a brownish black above and 

 color of the body beneath." The fly is described by Norton 

 as being black, with faint greenish reflections on the abdomen ; 

 there are two white bands at the base of the metathorax, and 

 the wings are banded. It is .30 inch long and the wings ex- 

 pand .70 inch. The larvae can easily be destroyed from their 



