532 SEVENTH REPORT OF THE FOREST, FISH AND GAME COMMISSION. 



Preventive ?\easai'es. 



The conditions obtaining in most of our American forests are such that we must 

 depend very largely upon natural agents of one kind or another to keep injurious 

 insects in check. The leaf feeding species noticed in the preceding pages are 

 subject to attack by a number of insect enemies and certain birds prey upon them. 

 This is true to a certain extent of the forms working in bark and wood, except that 

 the birds which can get at them are limited to fewer groups. Parasitic enemies 

 are valuable allies and occasionally it may pay to attempt the introduction into 

 localities where it does not occur of a form of well-known economic value, but 

 ordinarily very little can be done in the way of protecting insect enemies. 



Our native birds are exceedingly important checks upon the increase of vari- 

 ous insects, and perhaps as much can be done toward reducing insect ravages by 

 encouraging the presence of birds and preventing a decrease in their numbers as in 

 any other way. Dr. W. T. Hornaday, of the New York Zoological Society, estimated 

 a few years ago that there had been a decrease of about 48^ in the number of our 

 birds during the past 15 years. This decrease is very significant when taken in 

 connection with the enormous number of insects which birds devour. 



The Forest Tent Caterpillar, Clisiocampa dissiria Hiibn., has been causing very 

 serious injury in different sections of the State in the past 4 or 5 years and one 

 cannot help feeling that there may be some connection between this large decrease 

 in bird life and the abnormal abundance of this pest, especially when it is remem- 

 bered that 25 species of birds feed more or less upon this caterpillar. It would 

 seem wise to at least protect these forms so far as practicable and this may be done 

 by stopping the promiscuous gunning, prohibiting bird egging by boys and by 

 keeping hawks, crows and jays within bounds. 



The severe outbreaks of several bark borers in the last 2 or 3 years calls atten- 

 tion to their work and raises the question as to the possibility of controlling them 

 more thoroughly. Comparatively little will be done along this line in the case of 

 large tracts of forests, but in small areas, such as we find in the vicinity of Albany or 

 in other sections of the State not heavily forested, something may be accomplished 

 by carefuU}- cutting and then removing the infested trees or peeling the bark from 

 them and allowing the trunks to lie in the woods. It would seem as though the 

 value of the wood and timber would amply pay for the extra labor necessary to 

 remove these dying and dead trees. It is easy to detect them in winter, and as 

 nothing can be gained by allowing them to remain, they could be cut and disposed 

 of to the best possible advantage. These recommendations would apply not only 



