20 MAIXE AGRICULTURAL EXPERIMENT STATION. I913. 



shoots. They gnaw the base of the needles, separating them 

 from the twig, spinning them together by means of the silken 

 thread they secret. The larva thus forms a loose shelter, mov- 

 ing about in the space between the twig and the loosened nee- 

 dles and bud scale, and not. like many leaf-rolling caterpillars, 

 living in a regular tube. The seriousness of the attack of this 

 insect upon the conifers lies in the fact that the caterpillar 

 feeds upon the buds and new growth, not turning its attention 

 to the older growth until the young needles are entirely con- 

 sumed. A recurrence of the attack for two or three consecu- 

 tive years in severe infestations would cause the death of the 

 tree. 



The trees which are liable to attack are firs, spruces, larch 

 (or tamarack,)" hemlock and white pine. According to obser- 

 vations made by Mr. \Ym. C. Woods in the region about Houl- 

 ton, the firs are most susceptible. In woods where w^hite, red 

 and black spruce occur, the first mentioned is chiefly afi^ected. 

 At Houlton the larches were also injured. Our own observa- 

 tions made in the vicinity of Orono, Castine, east shore of Pen- 

 obscot Bay and Seal Harbor on Mt. Desert Island confirm 

 those of J\lr. Woods. On estates where the Norway spruce is 

 found it vies with the white spruce in susceptibility to attack. 

 The injur}^ to the trees is most conspicuous about the time the 

 larva is full grown, that is about the middle of Ju-ne in the vi- 

 cinity of Orono. At this time the fragments of the leaves left 

 by the worms and the frass are quite conspicuous, and at a dis- 

 tance trees which are seriously affected appear as scorched b}^ 

 fire (Fig. 8). Late in the season after the emergence of the 

 moths, wind's and rains have removed loose dry leaves and frass 

 so that the tree, unless the old foliage has also been eaten no 

 longer presents so desolate an appearance. 



The caterpillar (larva) begins feeding when growth starts in 

 the spring becoming full fed between the first and middle of 

 June. (Fig. 5). They are then about four-fifths of an inch 

 long, of a reddish brown color, and have small light yellow 

 warts on each segm.ent of the body, the sides of the caterpillar 

 are light in color. Sometimes they have a slightly greenish 



*Often though erroneously called the Juniper in Maine. 



