The Forest Caterpillar 119 



above and below, is the blue band, seen better in b of the same figure. As 

 seen in 6, which shows an enlarged side view of a segment, there is a second 

 and usually lighter line below the blue band. The under side is dull green, 

 ish with a large dark spot on each segment except the two front ones. As 

 the illustration shows, the back is more or less covered with rather thinly 

 scattered hairs, which are light, reddish brown, or almost black. The 

 whole body is sprinkled with black dots. 



This insect has long been called the tent-caterpillar of the forest, but it 

 makes no real tent and very rarely seeks shelter in the mat-like structure 

 which it does make. Still I think that some writers have not given the 

 caterpillar credit for making as much of a web as it often does construct. 

 It certainly never makes so conspicuous a web as does the ordinary tent- 

 caterpillar so common on apple and cherry trees, but it seems to me a de- 

 cided mistake to say that "they never make any tent or nest," as one of 

 our best entomologists asserts ; for while in a sense, this is true, yet to the 

 ordinary observer the matted web often seen would be regarded as of the 

 same sort as the real tent of the allied species. And not infrequently the 

 web of the forest worm is by no means an inconspicuous object. 



It is not usually located on the smaller branches, as is the web of the 

 tent-caterpillar, but on a large branch or, perhaps more often than else- 

 where, in the crotch of two large branches or of a branch and the trunk. 

 Still, I have occasionally seen webs on the twigs. Just why this species 

 spins a web is not altogether plain for it very seldom makes much use of it. 

 I have killed caterpillars in or under the web, but this is the exception ; 

 more often, they may be found clustered on it, though very frequently they 

 cluster where it is most convenient and pay little attention to the web. 

 The web is, usually, not white, but appears much as if ihickly dusted with 

 iron rust. Plate I shows a nest of the apple tree tent-caterpillar bear- 

 ing the clustered insects of both species for now and then the forest 

 caterpillar takes refuge in the tent of the allied species. I do not think 

 that the forest caterpillar ever makes so much of a web as that shown in 

 plate I; nor is its web stretched across several branches as shown in the 

 figure. 



CLUSTERING HABIT OF THE CATERPILLAKS 



Plate HI and figure 3 will recall a sight familiar to many of the resi- 

 dents of Vermont. These figures well show the customary position of the 

 caterpillars when at rest during the brighter and warmer parts of the day. 

 They also collect in this manner when rA^- f.^ „,„](;. At all times until 



