26 



when the beetles occur in great numbers that they can overcome the 

 resistance of the living trees. 



The following is a list of the common and scientific names of the 

 woodpeckers of northern New England, kindly prepared for me by 

 Dr. C. Hart Merriam, Chief of the Biological Survey, U. S. Depart- 

 ment of Agriculture: 



Hairy woodpecker Dryoba tes rillosus. 



Downy woodpecker Dryobates pubescent medianus. 



Arctic three-toed woodpecker Picoides arcticus. 



Banded three-toed woodpecker . _ _■ Picoides america n us. 



Yellow-bellied woodpecker . Sphyrapicus varius. 



Red-headed woodpecker Melanerpes erythrocephalus. 



Flicker. . ... Colaptes auratus luteus. 



Pileated woodpecker . Ceophlceus pileatus abietorum. 



Xo positive evidence was obtained as to which one or more of these 

 birds is to be credited with the larger part of the beneficial work, 

 but, from such observations as were made in the woods and informa- 

 tion given by Dr. Merriam, and through one of his correspondents, 

 Mr. William Brewster, at Bethel, Me., it would appear that the Arctic 

 three-toed and banded three-toed woodpeckers render by far the 

 greatest service, and probably do their principal feeding during the 

 winter on the species of insect now under consideration. 



A FUNGOUS DISEASE OF THE BEETLE. 



While quite a number of beetles and larva? were found which had 

 evidently perished from a fungous disease, the percentage dying from 

 this cause was not sufficient to be of any perceptible benefit. 



CLIMATIC CONDITIONS. 



While very severe freezing, or a sudden change from cold to warm, 

 or vice versa, may kill a great many of the pup?e, young beetles, and 

 even the larva?, except in a few cases but little evidence was found 

 showing that these conditions had produced appreciable effects. 



THE PRINCIPAL INSECT ALLIES OF THE SPRUCE-DESTROYING 



BEETLE. 



Among the large number of different kinds of insects which come 

 to the aid of the spruce-destroying beetle, or follow its attacks, 

 there are at least two which are worthy of especial mention in this 

 connection; one is the spruce Polygraphus, 1 or lesser spruce bark 

 beetle, while the other is the spruce Tetropium. 2 



THE SPRUCE POLYGRAPHUS. 



ill is is by far the commonest secondary enemy of the spruce 

 throughout the spruce region of West Virginia, and was found to be 

 exceedingly common in all of the sections visited in northwestern 



Polygraphias rufipennis Kirby. - Tetropium dnnamopterum Kirby. 



