greatest damage was done in the great inland spruce and balsam 

 forests of the northern half of the state which are the main 

 source of supply for the pulp mills. 



Usually one's attention is first attracted to this insect in 

 the spring or early summer by the wilted or blighted appearance 

 of the new growth at the ends of the branches and twigs of 

 spruce and balsam. This has often been described as resembling 

 the effect produced by the passage of a light fire through the 

 woods. If these blighted tips are examined they will be seen 

 to be made up of the ends of the needles or leaves of the new 

 spring growth which has been gnawed through at the base, 

 but are still held loosely together by a silken, web-like substance. 

 If one of these loose masses is opened, one or several caterpillars 

 are likely to be found within. These are the culprits responsible 

 for the damage. Each when about full grown is from one-half 

 to three-quarters of an inch long, with dark, nearly black head 

 and with body of a general brown color, more or less diffused 

 with green at the sides. Each segment has several light colored 

 warts, dark at the center from which arises a hair. The insect 

 begins feeding in the spring soon after the development of the 

 new needles and as they eat only the bases of these, the entire 

 new growth is usually destroyed before the caterpillar reaches 

 its full size about the middle of June. The uneaten portions of 

 the leaves are held together by means of a silken thread spun by 

 the larvae, which thus forms a loose but more or less complete 

 covering or shelter in which it remains at all times. If all of 

 the new growth is destroyed before the larvae becomes full fed, 

 it extends its operations toward the base of the twig and feeds 

 upon the older needles. 



The larvae are usually full grown during the first half of 

 June, and, still in their loose shelter of gnawed-off needles, trans- 

 fers forms to pupae. These, in the course of the next week or two, 

 give rise to medium sized, brownish-gray moths, which in infest- 

 ed regions are flying in numbers during the last week in June 

 and the first half of July. The moths deposit their eggs in small 

 light green masses on the sides of the needles. These eggs are fiat 

 and rather scale like and are so placed that they form small oval 

 masses which are so inconspicuous as to escape casual notice. 

 The eggs are all laid before the last of July and the larvae from 

 them hatch in a week or ten da vs. These minute larvae feed for 



