56 



teenth inclusive, has two tubercles, one on each side, and in a line with the long horns on 

 third segment, each crowned with a cluster of whitish spines; the tubercles on sixth and 

 twelfth sef,ments are much larger than the others those on the eleventh and terminal seg- 

 ments next in size, those on the ninth smallest. The tubercles on the seventh, eighth, tenth 

 and eleventh segments have a streak of wliite at their base, and each segment behind fourth, 

 excepting ninth, has several smaller tubercles of a bright blue colour. A large whitish patch 

 covers nearly the whole of the ninth and parts of the eighth and tenth segments, and another 

 •of a similar character covers the second, third and part of the fourth. A white stripe ex- 

 tends along each side, close to the under surface, from the fifth segment to the end of the 

 body, and in which is set a small cluster of whitish spines about the middle of each segment, 

 from sixth to tenth inclusive. On each .side of seventh, eighth and tenth segments is an 

 elongated blackish spot, just above and behind the spiracles; the terminal segment has two 

 dark greenish brown spots above in front of the tubercles. The spiracles are rather large, 

 oval and brownish-black. 



The under side is whitish-grcon, with a central dull white stripe on the hinder segments ; 

 the feet are brown, ringed with brownish-black ; the prulegs pale greenish, faintly tipped with 

 brown. 



This caterpillar varies somewhat in colour, some specimens being of a paler green than 

 that just described. 



The chrysalis, Fig. 46, h, Mr. lliley describes as " marked with burnt uDjber, brown, 

 ash grey, flesh colour and silvery white, and is characterized, like that of the other species of 

 the genus, by a curious, thin, almost circular projection, which has been likened to a Roman 

 nose, growing out of the middle of its back." 



There are two broods of this in.sect during the year ; the larvte resulting from the eggs 

 deposited by the second brood usually attain to less I ban half their full growth before winter, 

 when they hybernate and complete their growth the followinn; spring. The interesting pre- 

 parations made by these caterpillars in the construction of little cases, in which they rest 

 tolerably secure from harm while in this state of torpor, is thus described by Mr. Riley 

 " First and foremost — with wise forethought, and being well aware through its natural ins- 

 tincts that the leaf which it has selected for its house will fall to the ground when tlie cold 

 weather sets in. unless it takes measures to prevent this — the larva fastens the stem of the 

 leaf with silken cables securely to the twig from which it grows. It then gnaws ofl' the blade 

 of the leaf at its tip end, leaving little else but the mid-rib, as shown in Fig. 46, (/. Finally, 

 it rolls the remaining part of the blade of the le^if into a cylinder, sewing the edges together 

 with silk. The basal portion of the cylinder is, of course, tapered to a point, as the edges 

 of the leaf are merely drawn together, not overlapped ; and invariably the lower side of the 

 leaf forms the outside of the house, so as to have its projecting mid-rib out of the way of 

 the larva, as it reposes snugly in the inside. The whole when finished (see Fig. 46, c,) has 

 somewhat the appearance of the leaf of a miniature pitcher plant. These curious little cases 

 may be commonly found upon our willows or poplars in winter time. 



This insect is liable to the attacks of several parasites, which effectually prevent its in 

 crease beyond certain limits. One of the.se parasites is a tiny dark four-winged fly, which 

 infests the eggs of the disijfvs but'erfly ; anothtr is a very small black four-winged fly ; and 

 a third a larger two-winged fly, both of which attack the insect in its caterpillar state. 



The HELLGR.iMMiTE Fly {Cori/dalls cornuhts — Linn.). 



This is an insect which is not uncommon throughout Ontario, and whenever and wher- 

 ever found, either in the larval or perfect state excites much surprise and curiosity from its 

 large size and formidable appearance ; it is not, however, in any way poisonous, as some 

 people imagine it to he. In Fig. 47 this insect is represented in its several stages, while the 

 expanded female is shown in Fig, 48. The larva — a most diabolical looking creature, a, Fig. 

 47 — spends the earlier portion of its life in the water, crawling and swimming about upon 

 the bottoms of rivers and streams, feeding upon the larva^ of various other insects which also 

 inhabit the water. Mr. Riley has published a very interesting account of this insect in the 

 first vol. of the American Entomologist, from which most of the following remarks are con- 

 densed. 



Most aquatic larvae spend the period of their chrysalis state in the water, and only 

 emerge therefrom when ready to pass into the perfect or winged state ; but the insects form 



