32 Agkictjltural Experiment Station, Ithaoa, N. Y. 



them. This tying together of leaves and flowers and the brown 

 appearance of many of the leaves are the most characteristic indications 

 of the presence of the pest on large trees. 



In some cases, especially on the tender shoots of young trees, the 

 caterpillar, after destroying the bud, burrows down the center of the 

 shoot, thus causing it to die back for several inches. 



Later in the season, in July, the work of the recently hatched 

 caterpillars may be seen on the under side of the leaves (Fig. 1). 

 They feed upon the lower side of the leaf near the mid-rib, leav- 

 ing the veins and upper epidermis of the leaf. As the area over which 

 the caterpillar has fed soon turns brown, its work is quite easily seen. 

 The number of leaves found thus affected in July and August will 

 indicate whether the pest will be numerous the coming spring or not. 

 The reason for this will appear when we treat of the life history of the 

 pest. M 



There is nothing about the appearance of the tree itself in winter 

 that would indicate whether the pest was present or not. As the cater- 

 pillars hibernate and are so securely hidden, it would be very difficult 

 for an ordinary observer to find them and thus to determine whether 

 the pest is present in alarming numbers. 



The Appearance of the Pest. 



The larva or caterpillar.- -This is the stage of the insect which is 

 the most familiar to fruit growers. When first hatched, the larvae are 

 about .04 of an inch (1 mm.) in length, slightly hairy, and of a light 

 green color with a dark brown shield on the first thoracic segment; 

 the head is nearly twice as wide as the body and of a shining dark 

 brown color. In a few hours the larva changes to a light seal-brown 

 color and the head and thoracic shield become nearly black. The larvae 

 go into hibernation when about half grown, and appear upon the open- 

 ing buds in the spring as little light brown caterpillars, about .16 of an 

 inch (4 mm.) long, with a black head and thoracic shield; the anal 

 shield on the dorsum of the last segment is scarcely darker in color 

 than the body. 



In June when the larvae are full grown (Fig. 1) they measure about 



Fio. 1. — The larva, about three times natural siao. 



one half an inch (13 mm.) in length and are of a cinnamon brown 

 color, with the head ^and thoracic shield shining black and the anal 



