REPORT OF THE ENTOMOLOGIST. 



375 



Two large living spruces, the wood full of sap and the leaves fresh 

 and green, were examined, and in the bark were numerous beetles of 

 the genus Hylurgops, both in the worm or grub state and in the beetle 

 stage. These beetles, while in the youug or worm condition, run their 

 galleries into the sap-wood and partially girdle the tree. There were 

 enough worms in these trees to ultimately kill them, and there was no 

 doubt but that these two trees were doomed to death by this cause. We 

 mention these cases especially, as it is doubted by some entomologists in 

 Europe whether living, healthy trees are attacked by borers. Our ex- 

 perience teaches us that not only spruces, firs, and pines are attacked 

 and killed by boring beetles, but the experience of others, notably that 

 of Dr. C. Hart Merriam, shows that entire groves of sugar-maphi sap- 

 lings in Northern New York have been killed outright by a little bark- 

 borer. His account is published in full in the American Naturalist for 

 January, 1883, p. 84. The following extract will show the nature of the 

 attack and the result to healthy, living trees : 



About the 1st of last August (1882) I noticed that a large percentage of the under- 

 growth of the sugar -maple in Lewis County, Northeastern New York, seemed to be 

 dying. The leaves drooped and withered, and finally shriveled and dried, but still 

 clung to the branches. The majority of the plants affected were bushes a eeutimeter 

 or two in thickness, and averaging from one to two meters in height, though a few 

 exceeded these dimensions. On attempting to pull them up they uniformly, and al- 

 most without exception, broke off at the level of the ground, leaving the root undis- 

 turbed. A glance at the broken end sufficed to reveal the mystery, for it was perfor- 

 ated, both vertically and horizontally, by the tubular excavations of a little Scolytid 

 beetle which, in most instances, was found still engaged in his work of destruction. 



At this time the wood immediately above the part actually invaded by the insect 

 was still sound, but in a couple of months it was generally found to be rotten. Dur- 

 ing September and October I dug up and examined a large number of apparently 

 healthy young maples of about the size of those already mentioned, and was some- 

 what surprised to discover that fully 10 per ceut. of them were infested with the same 

 beetles, though the excavations had not as yet beeu sufficiently extensive to affect 

 the outward appearance of the bush. They must all die during the coming winter, 

 and next spring will show that in Lewis County alone hundreds of thousands of 

 young sugar-maples perished from the ravages of this Scolytid during the summer of 

 1882. 



As has been stated in our Bulletin on Forest -tree Insects, it is well 

 known that healthy, large sugar-maples are often attacked and killed 

 outright by the borer which attacks that valuable shade tree. The in- 

 stances of the death of healthy trees of various kinds from the attacks 

 of internal pests or of bark-boring beetles are so numerous that we 

 are now inclined to believe that the death of the spruces in North- 

 ern New York and New England is almost wholly due to this cause. It 

 is the belief among some lumbermen that the spruces are dying of old 

 age. There is undoubtedly a natural limit to the life of any tree, but 

 why should this cause have been confined to the spruce only within 

 the last ten or fifteen years? Spruces, like other trees, have died of old 

 age since the world began ! Again, summer droughts and winter storms 

 and severe cold weather should not affect the spruce more than any other 

 tree of our forests, especially the pine and the hemlock. On the con- 

 trary, the spruce is our hardiest tree. It lives farthest up on mountain 

 summits; it is the northernmost of our evergreen trees, living nearer 

 the Arctic circle than even the larch. It can withstand severe drought, 

 nourishing on rocky ground where the soil is thinnest; it grows luxuri- 

 antly in swamps where the ground remains frozen later than elsewhere, 

 and the arrangement of its branches enables it to withstand heavy 

 snows and winter storms as well, if not much better, than any other tree 

 of our northern forests. The adverse forces of nature, winds, gales, 

 frost, snow, sudden heat, and drought have acted for ages upon the 



