INSECTS AFFECTING PARK AND WOODLAND TREES 



IXTRODrCTIOX 



The welfare of the human race is ch)sel\- connectixl with that of our 

 trees, ami any work looking- to th^-ir better protc-ction makes for the 

 advancement of mankind. The value of our str(-(;t and park trees is much 

 greater than the cost of their production, and a city or village blessed with 

 such has treasure which should Ije most jealousl)- guanled, since these 

 magnificent growths have an important inHuence in modifying climatic 

 conditions, besides adding materially to the beaut\- of the surroundings. 

 I his is not only true in cities ami villages but also in the country at large, 

 particularl)- in sucli resorts as the Adirondacks, where thousands go for 

 recreation and health. The trees in such places not only afford most 

 agreeable shelter from wind and sun, but the e\aporation from the immense 

 leaf areas modifies the temperature and the exhalations from the coniferous 

 needles undoubtedly aid very much in healing diseased lung tissues. 



The protection of shade trees is a serious |)roblem, largely due to the 

 introduction into this country of certain \rry destructive species, such as 

 the gipsy moth, the elm leaf beetle, the i-lm bark louse, the leopard moth 

 and the San Jose scale, all e.\ceedingl\- injurious and all, cxcei^t the 

 'gipsy moth, well established in New \'ork State. It is only a (piestion 

 of time before the latter crosses our borders. The al)ovi- are a few of the 

 important exotic species which aid such dtrstruclixc native forms as the 

 white marked tussock moth, the iKigworm, the fall webworm, the scurfy 

 and o\ster scales and the cottony maple scale in their nefarious work. 



Injuries caused by insects. It is very tlitiicult for most ])ersons to form 

 an adecjuate idea of the great economic im|iortance of this group. The)- 

 are willing to admit that some injury is causeil, but have no adecjuate con- 

 ce|Jtion of the enormous losses inllicted. I'Or example, during 1854 to 

 1857, the wheat midge, Dijjlosis tritici I-'itch. caused an estimated 



