84 INSECTS INJURIOUS TO THE APPLE. 



the same time giving off a disagreeable odor, which is doubt- 

 less used as a means of defence against its enemies. On each 

 side of the third segment is an eye-like spot, nearly oval^ 

 yellow, enclosed by a ring of bJack, centred with a small 

 elongated blue dot, which is also set in black. On the hinder 

 portion of the fourth segment is another raised yellow fold, 

 bordered behind with rich velvety black ; the latter is seen 

 only when the larva is in motion. On the terminal segment 

 there is a similar fold, flattened above, with a slight protu- 

 berance on each side. On the fifth segment are two blue 

 dots, one on each side, and there are traces on the hinder 

 segments of similar dots, arranged in longitudinal rows. 

 The under surface is paler than the upper, with a whitish 

 bloom. \ 



When the caterpillar is about to change to a chrysalis^ 

 which is usually during the early part of August, the color 

 of the body grows gradually darker, until it becomes dark 

 reddish brown, with the sides nearly black, and the blue 

 dots become much more distinct. Having selected a suitable 

 spot in which to pass the chrysalis state, it spins a web of 

 silk, into which the hooks on the hind legs are firmly fastened f 

 then, having prepared and stretched across a silken band or 

 loop to support its body in the middle, it casts its larval skin^ 



and remains a dull-brown chrysalis, of the 

 Fig. 82. form shown in Fig. 82, until the following 



spring. 



This insect is very widely distributed,, 

 being found in nearly all parts of the 

 United States and Canada. The caterpil- 

 lar feeds on a number of different trees, 

 but chiefly affects the apple, cherry, thorn, 

 and basswood. As it is always solitary in its habits, it is 

 never likely to cause much injury. South of Pennsylvania 

 the female of this species of butterfly usually loses its yellow 

 color and becomes nearly black, while the other sex retains- 

 its normal hue. 



