FOREST COMMISSIONERS REPORT. 9I 



And, indeed one may travel through the spruce forest of the 

 coast from Portland to Rockland and meet with similar sights." 

 It was not, however, till the spring of 1909 that this insect again 

 began to attract attention, tirst in Pennsylvania and later in 

 New York and Canada. In 1910 it was much worse in the 

 centers of the infestation, and in 1911 it had spread to the coast 

 of Maine where its work is now attracting so much attention. 

 This season the pest is widely distribtited over the state, reports 

 having been received at the Experiment Station from localities 

 in Aroostook, Penobscot, Hancock, and Piscataquis counties, 

 and it very probably occurs in others. 



The insect which is responsible for the destruction is a small 

 caterpillar about three-quarters of an inch in length when full 

 grown. Its head is blackish, the body ranging from pale brown 

 to a rich umber brown, diffused with green, each joint with 

 several conspicuous whitish warts each with a dark center from 

 w'hich a single hair arises. The miller or moth is about one-half 

 inch in length, measuring when spread out nearly an inch tron^ 

 tip to tip of wing. The legs, body and hind wings are a glisten- 

 ing umber brown, the fore wings have a ground color of bluish 

 gray and when freshly emerged marked with several conspicu- 

 ous blotches and dashes of very dark brown to almost black. 



The eggs which are laid soon after emergence of the moth 

 are pale green, scale-like, flat beneath, and slightly convex 

 above. 



The insect passes the winter on the trees as very small cater- 

 pillars which, as soon as the new growth starts in the spring, 

 begin to feed on the leaves of the terminal twigs, thus causing 

 the brown and withered appearance of the trees. These cater- 

 pillars stop feeding by the middle of June and transform to the 

 chrysalis or pupal stage in thin webs among the living and dead 

 needles at the ends of the branches, not always, however, in 

 the suspended position as shown in the illustration. By the 

 first of July the adults begin to come out from the chrysalis 

 .stage and appear on the wing as small grayish moths, often 

 appearing in vast numbers on the trees and flying to light. They 

 continue to fly and to deposit their eggs in small greenish 

 masses on the needles until about the middle of July, when the 

 moths die and disappear. The eggs soon hatch and the young 

 caterpillars become partly grown before the end of autumn 



