INSECTS AFFECTING PARK AND WOODLAND TREES 25 



related European inaiuis, Mantis rclij^iosa Linn., which has recently 

 become established in New \'ork Stati, and has bern distributed to several 

 localities through the efforts of the writer, ma\- ()ccu|)y a similar position in 

 the northern states, should it prove able to withstand the severities of our 

 winters and become somewhat al)unclant, as ap|)ears verj- probable. 



C, F.X I'.RAL. I'R !•: V KNTI VE M R ASU R RS 



The control of insects, particularly in forests, must be effected very 

 largely through the activity of natural agents, which should be encouraged 

 in every possible way. It is ordinarih' impractical to attempt much in 

 either a preventive or a remedial way, in the forests of the United .States. 



Birds. Among repressive measures perhaps nothing is so effective in 

 forest entomology, as encouraging or protecting the natural enemies of 

 insects depredating on the trees, chief among which may be ranked our 

 native insectivorous birds. Considerable has been written on this subject 

 in recent years, ami wldle it is undoubtedly true that there are two sides to 

 the question, it is cpiite certain that birds are exceedingly useful checks 

 on soiTie of our more destructive insects. The recent widespread and 

 disastrous outbreaks of the forest tent caterpillar, Malacosoma 

 disstria Hiibn., in New York may be charged, in part at least, to the 

 abnormal scarcit)- of birds. The investigations of Dr William T. Hornaday 

 of the New York Zoological Society, show that in this State there has been 

 a decrease of about 48,';^ in the number of our birds during the past 15 years. 

 These figures, taken in connection with the enormous number of insects our 

 feathered friends devour, are very significant. 



The following observations from Mr E. H. Forbush," ornithologist to 

 the Massachusetts State Board of Agriculture, give an excellent idea of the 

 voracity of birds. 



Birds are remarkably active and energetic creatures, requiring a tre- 

 mendous amount of food to sustain them in their efforts and to repair the 

 waste of the tissues. 



Some of the smaller birds require only half an hour to an hour and 



■ 1904 N. J. State Bd. .^gric. 31st Rep't 1903. p. 192-93. 



