INSECT PESTS OF OHIO SHADE AND FOREST TREES 167 



with which the tree must cope when we take it from the environ- 

 ment of the "God-made country" and transplant it to that of the 

 "man-made town." Perhaps no other single feature handicaps the 

 tree sO' severely in its new location as does that of insect attacks, 

 since insect injuries are much more common to city trees than to 

 those growing in the country. 



On the other hand, insect scourges occasionally develop over 

 widespread urban districts, as, for instance, the outbreaks of the 

 locust leaf beetle in southern Ohio, the oyster shell bark louse 

 scourges of northern Ohio, and the caterpillar invasions of the last 

 three years which swept the woodlands of the southern section of 

 the State. 



In view of the natural existing conditions, therefore, the pres- 

 ent publication will in the main be of greater practical value to the 

 city man, but it will fill the needs of the man in the country as well. 



FACTORS ASSOCIATED WITH INSECT CONTROL IN CITIES 



EFFECTIVE INSECT CONTROL DEPENDS ON THE SELECTION OF SUITABLE 

 SPECIES OF TKEES AND IN THEIK PROPER PLANTING 



The problem of city insect control does not lie essentially in the 

 field of pure entomology, thus concerning itself merely with the 

 attempted annihilation of each individual pest as it appears, but in 

 order to yield success it must be based upon a framework of ecologi- 

 cal conditions reaching far into other branches of science. The 

 present publication, in order to present a semblance of completeness, 

 must therefore consider at least briefly some of these allied points. 



The correct selection of species for planting; the first step 

 towai'd insect control. — The control of insect pests begins with the 

 very act of selecting the tree to be planted, indeed, with the spot to 

 be occupied by the tree. A casual observer will notice that some 

 trees are severely beset by insect pests while others are scarcely 

 ever attacked ; hence it is advisable to select non-susceptible species 

 which at the same time combine with this feature natural beauty, 

 longevity and rapidity of growth, as well as other desirable char- 

 acteristics. How often does the one item, rapidity of growth, 

 decide the species to be used and this accounts in large measure for 

 the predominance of the Carolina poplar or cottonwood and the soft 

 maple in many of the newer sections of our cities — ^both trees of 

 little value for the permanent adornment of lawn or street. 



Dr. E. P. Felt, in his most excellent memoir on "The Insects 

 Affecting Park and Woodland Trees," has tabulated the more com- 

 mon trees of New York state with relation to their liability to 



