30 



refuge from their enemies, or shelter from inclement weather. The web is spun in con- 

 ceit, each one doing his own part in the construction of this convenient home for the little 

 ejmmunity. 



They have their regular times for feeding, issuing from the orifice of their tent in 

 processional order, usually once in the forenoon and once in the afternoon. In about sbc 

 weeks they become full grown, and then present the appearance shown at a and h, fig. 7 ; 

 a shows a side view and b a back view of the same caterpillar. The body is black, about 

 two inches long, with a white stripe down the back. On each side of this central stripe 

 there are a number of .short irregular longitudinal yellow lines. On the sides are paler 

 lines, with spots and streaks of pale blue. The under side of the body is nearly black. 



As these caterpillars approach maturity, they lose their social habits, and, leaving 

 their friends and kindred, they wander about singly in all directions. The main object of 

 this disper.sion seems to be the finding of separate and secure retreats, in which to pass 

 tlie chrysalis stage of their existence — in crevices in the rough bark of trees, on the lower 

 edges of boards where they are nailed to the posts offences, in holes in the posts, and in a 

 variety of other situations of a similar character, where they will be sheltered from the 

 weather. Here their cocoons are spun, and within the enclosure the larva changes to a 

 chrysalis. The cocoon is oval, of a pale yellow colour (see d, fig. 7), and in its construc- 

 tion the silk is mixed with a pasty substance which, when dry, becomes powdery, and is 

 partlj' removed from the surface of the cocoons by handling. The chrysalis, which lies 

 within the.cocoon, is about three-fourths of an inch long, and of a pale brown colour. 



At the expiration of two or three weeks the moths escape from the cocoons. They 

 are of a dull reddish colour, varying in depth of shade, with two straight whitish stripes, 

 which extend across the fore wings obliquely, dividing the wing into three nearly equal 

 portions. The females sometimes have the two stripes closer together \ in the males they 

 are less variable. The hind wings are nearly of the same colour as the^front ones, but 

 without any stripes. In both, the under surface is very similar to the upper, and the 

 wings when expanded measure from 1| to 1^ inches or more. 



The moths usually appear early in July, when, on sultry evenings, they come thump- 

 ing against the lighted windows of our houses, and if they gain access, they fly about the 

 lights in the room with great rapidity, and in the wildest and most bewildered manner, 

 striking violently against any and every object which opposes their progress. A few 

 days after their appearance on the wing they pair, and then the females begin to de- 

 posit their eggs on the twigs of our fruit trees, in the belt-like masses we have already 

 referred to. 



Another and a very similar species is known as the " Forest Tent Caterpillar " (Clisi- 

 ocampa sylvatica), so called because it is frequently found on forest trees, although it is also 

 very destructive to the apple. The eggs are laid in the same manner as the last species 

 named, and in masses about the same size ; the caterpillars, too, resemble each other, but 

 may be at once distinguished by the peculiar markings down the back. In the former 

 Fif;. 8. sjjecies the white forms a continuous and prominent 



stripe ; in this one the stripe is replaced by a row of 

 white spots (see fig. 8). There are other minor points 

 of difference, but this one character is invariable, and 

 will enable any one to separate the species without 

 difficulty. Some few years ago the western section 

 of Ontario was overrun by this caterpillar, whole 

 orchards having been completely defoliated as if a 

 fire had passed over them, and the trees greatly damaged thereby; but the vigilance of our 

 farmers, aided by the natural enemies of these insects, has been successful in reducing 

 their numbers so considerably that they have ceased to be a source of much anxiety. These 

 caterpillars usually select the side of a tree on which to spin their web, rather than a fork 

 of one of the limbs, and when nearly full grown scatter as in the case of the other species, 

 and wander about singly in search of suitable locations in which to spin their cocoons. 

 These latter are scarcely distinguishable from that already described; the moths also may 

 easily be confounded with those of Americana, but they are usually sojnewhat smaller in 

 size and paler in colour, while the oblique lines on the anterior wings are dark in place of 

 nearly white. 



