INSECTS AFFECTIXC PARK AND VVOOULAXD TREES 25 



related European mantis, Mantis relij^iosa Linn., which has recently 

 become established in \e\v \'ork State, and has been distributed to several 

 localities through the efforts of the writer, may occui))- '^ similar [josition in 

 the northern states, should it prove- aljli- to withstand the severities of oiu' 

 winters and become somewhat abundant, as appears \cry probable. 



GENERAL PREVENTIVE MI'.A.SL RE.S 



The control of insects, ])articularl\- in forests, nnist lie effected very 

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

 in every possible way. It is ordinarily impractical to attemi^t much in 

 either a preventive or a remedial way, in the forests of the L'nited .States. 



Birds. Among repressive measures perhaps nothing is so effective in 

 forest entomolog)-, as encouraging or protecting the natm-al enemies of 

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

 native insectivorous liirtls. Considerable has been written on this subject 

 in recent years, and whih- it is undoubtedly true that there are two sides to 

 the question, it is (|uite certain that birds are exceedingly useful checks 

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

 tlisastrous outbreaks of the forest tent caterpillar, Malacosoma 

 disstria Hiibn., in New \'ork may be charged, in |)art at least, to the 

 abnormal scarcity 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 l)irds dm-ing the past 15 years. 

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

 feathered friends devom-, 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, recjuiring 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 on!)- half an hour to an hour and 



1904 N. J. State Bd. Agric. jrst Rep't 1903. p. 192-9,5. 



