REPORT OF THE SOCIETY 35 



Danger from Fires 



It is evident that the fire hazard caused by this great quantity of dead and 

 dying trees constitutes a most serious danger. There can be no doubt that fire 

 fighting will be made more difficult for the next few years from this cause, and 

 there was evidence last year that certain large fires spread largely in this dead 

 and dying balsa'm. 



Insects concerned in the Injury 



The Spruce or Balsam Budworm, Harmologa fioniferana Clem., is a small 

 brownish caterpillar about three-fourths of an inch in length when full grown. 

 The adult insect is a small, yellowish-brown moth which flies readily, deposits 

 its eggs on the needles of living trees and so distributes the injury. The tiny 

 •caterpillars, which have overwintered on the twigs, appear in the early season 

 and attack the opening buds and young foliage. They feed upon balsam, spruc- 

 es and hemlock; but they affect the greatest injury to balsam and red spruce. 

 When the caterpillars are exceedingly numerous, as in an outbreak, the young 

 foliage on the balsam is largely or completely destroyed and the older needles 

 eaten to a varying degree. Before the dead needles have fallen, the badly in- 

 fested trees have a reddish, scorched appearance, which is replaced by a greyish 

 €olor in the later stages of the infestation after the foliage has largely disappeared. 

 The caterpillars are abundant usuallj' for only two or three years, dying out 

 through the combined effects of parasites, predators, lack of food supply and 

 adverse weather conditions. Towards the close of the outbreak redtop bal- 

 sams, i. e., dead trees with all the remaining foliage turned red, appear, indica- 

 ting the work of the beetles and fungi which seem invariablj^ to follow a bud- 

 worm outbreak. 



The Balsam Bark-beetle, Pityokteines sparsus Lee, is a \evy small, black 

 beetle, one-eight of an inch in length, found, with its small whitish grubs, cutting 

 tunnels in the inner bark on the surface of the sapwood of weakened and dying 

 balsams. The beetles excavate a minute entrance tunnel through the bark, 

 terminating in a small flattened chamber on the surface of the sapwood, from 

 which radiate several egg-tunnels. These, together with the entrance tunnels, 

 are kept free from boring-dust. The star-shaped tunnels thus formed are occu- 

 pied by one male and several females, one for each individual egg-tunnel. The 

 eggs are laid in niches along the sides of the latter, and the tiny white larvae or 

 grubs excavate slender larval mines which are packed behind the larvae with 

 dustlike excrement. The larvae pupate in the ends of their mines and even- 

 tually cut their way through the bark to freedom to attack fresh balsam 

 slash, and weakened or recenth' killed trees. 



This species breeds abundantly in balsam slash and in dying and weak- 

 ened balsams but rarely, if ever, attacks healthy trees. 



