12 FOOD OF WOODPECKERS OF UNITED STATES. 



a tangential or circular cut across the punctures gives a bird's-eye 

 appearance very similar to that which Nature produces in some 

 maples. A radial cut through the punctures gives the curly look 

 often found in many woods. It frequently happens, however, that 

 water enters at the punctures and causes a slight decay, which usually 

 disfigures the wood by making a dark stain, though occasionally the 

 effect is ornamental. 



With the possible exception of the crow, no birds have been subject 

 to so much adverse criticism as the woodpeckers. When they are 

 seen scrambling over fruit trees and fresh holes are found in the bark, 

 it is concluded that they must be doing harm. But woodpeckers, 

 except a few species, rarely disfigure a healthy tree, but when they 

 find a tree infested by wood-boring larvae, they locate the insects 

 accurately, draw them out, and devour them. If in succeeding 

 years the burrows formerly occupied by the larvae are used by a 

 colony of ants, they in turn are dug out and destroyed. 



The following are samples of testimony by Dr. Hopkins arid other 

 eminent entomologists to the persistent and effective work of wood- 

 peckers in destroying wood-boring beetles and other insect enemies 

 of trees: 



As has already been stated, woodpeckers are the most important enemies of the 

 bark beetle, and appear to be of inestimable value to the spruce-timber interests of 

 the Northeast. Indeed, I feel confident that in the many hundreds of infested trees 

 examined at least one-half of the beetles and their young had been destroyed by the 

 birds, and in many cases it was evident that even a greater proportion had perished 

 from this cause alone. 



Estimating 100 beetles to the square foot of bark in the average infested tree, and 

 an average of 60 square feet of infested bark, it is possible for each tree to yield an 

 average of 6,000 individuals; 100 trees, 600,000, and so on. It is 'therefore plain 

 that, if one-half or two-thirds of this number are destroyed by the birds and other 

 enemies, the amount of timber the remainder can kill will be lessened. This is all 

 the more apparent when it is remembered that it is only when the beetles occur in 

 great numbers that they can overcome the resistance of the living trees. 1 



Birds contribute their share, also, in destroying larvae and pupse. The work of 

 woodpeckers was found upon most of the trees which had been killed by Dendroctonus 

 brevicomis, and these birds had evidently destroyed a large percentage of the insects 

 in some of the trees. 2 



As natural enemies of this insect [the maple borer, Plagionotus speciosus] it is prob- 

 able that various species of woodpeckers render the greatest service. At Huntington, 

 Mass., I have seen the hairy woodpecker, the downy woodpecker, and the flicker 

 feeding upon white larvse taken from beneath the bark of maples infested by this 

 borer. 3 



Woodpeckers do much good by hammering holes in the bark of infested cotton woods 

 and devouring the young carpenter worms [larvse of Cossus populi]. We certainly 

 ought to protect these feathered friends of ours instead of allowing every small boy in 

 the country to shoot them whenever he pleases. 4 



1 Hopkins, A. D., Bull. 28 (new ser.), Division of Entomology, U. S. Dept. Agric., pp. 23, 25-26, 1901. 



2 Webb, J. L., Bull. 58, Part II, Bureau of Entomology, U. S. Dept. Agric., p. 27, 1906. 

 * Kirkland, A. H., in Mass. Crop Report for June, 1897, p. 32, 1897. 



< Doten, S. B., Bull. 49, Nevada Agric. Exper. Sta., p. 12, 1900. 



