REPORT OF THE ENTOMOLOGIST. 147 



whether in high and exposed situations or in hollows ; occasionally from 

 such centers the worms seein to have increased and spread from year to 

 year, until all the trees in localities several square miles in extent were 

 killed. Moreover, as we have seen in the case of the attacks of the larch 

 worm, the defoliation of spruces and firs repeated two and perhaps three 

 summers is sufficient to either kill the tree outright, or so weaken it that 

 bark-boring beetles can complete the work of destruction. We are now 

 inclined to the opinion, then, that the Bud Tortrix is the sole or at 

 least main cause of the destruction of spruces and firs in Cumberland 

 and Sagadahoc and Lincoln Counties, Maine, and that by their attacks 

 they render the trees liable to invasion by hosts of bark beetles. 



ITS HABITS AND TRANSFORMATIONS. 



The spruce-bud worm, as we observed in Cumberland County, also at 

 Phillips, and near the Eangeley Lakes, on the road from Phillips to 

 Eangeley, where the trees by the roadside, as well as in the woods, 

 were attacked by them, so that they looked as if a light fire had passed 

 through them, feeds upon the leaves or needles of the terminal shoots, 

 both the first and previous year's growth. The worm gnaws the base 

 of the needles, separating them from the twig, meanwhile spinning a 

 silken thread by which the needles and bud-scales are loosely attached 

 to the twig ; the worm moving about in the space between the twig and 

 the loosened needles and bud-scales, and not living like many leaf-rolling 

 caterpillars in a regular tube. 



The caterpillar sometimes draws together two adjacent shoots, but 

 this is rarely done; hence while it is at work it scarcely alters the appear- 

 ance of the tree, and its presence is only known when the worms are 

 abundant enough to partly defoliate the trees. 



The worms in June, 1883, were in Cumberland County most abundant 

 where the dead or partially dead spruces abounded ; but individual 

 worms could be obtained by beating any spruce or fir in any locality, 

 showing that in years of immunity from its attacks the insect is a com- 

 mon and widespread species. We found the worms most abundant in 

 spruces, firs, and even hemlocks, July 1 and 2, between Phillips and Eange- 

 ley, but after passing through all the Eangeley Lakes, and going from 

 Errol, K. H., to Berlin, Gorham, Jackson, and Conway, $". H., we found 

 that the spruces and firs throughout Northwestern Maine and the White 

 Mountain regions had suifered no widespread damage. One and per- 

 haps two rather extensive tracts of dead spruces were observed at a 

 distance from the stage road near Eangeley, but throughout the vast 

 spruce-clad forests observable from the lakes themselves no such tracts 

 of dead trees were to be seen. On the contrary, the spruce forests of 

 the Eangeley Lake region appeared to be as green and fresh as any 

 forest we have ever seen. The dead spruces at the water's edge of the 

 middle lakes were evidently due to the high water held in by the middle 

 and lower dams during the last two years. As in any forest, there were 

 individual dead trees, sometimes small clumps of them, where the trees 

 had died as the results of tornadoes or of borers. The persons living 

 by the lakes, lumbermen and others, informed us that there had been 

 no extensive destruction of evergreen trees in this region. 



The spruce-bud worm attains its full size and stops feeding, ready 

 to transform to a chrysalis, in Cumberland County by the 20th to 30th 

 of June, and about the Eangeley Lakes and in the White Mountain 

 region a few days or nearly a week later. 



When about to change to a pupa it remains in its rude shelter or 

 hiding place under the loosened leaves of the shoot, where it turns to a 



