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OHIO EXPERIMENT STATION: BULLETIN 332 



insect attack. As Ohio conditions are not vastly different from 

 those found in New York state, Doctor Felt's rating in the main 

 holds good here. With a few additions and alterations made on 

 account of the variation in Ohio conditions as compared with New 

 York, the rating is as follows : "The figure 3 has been placed oppo- 

 site trees which are practically immune from insect injury; 2.5 

 indicates some damage. Trees having one somewhat serious enemy 

 are rated at 2 and those having at least one notorious insect pest 

 at 1.5. Greater likelihood of injuries is indicated by 1 and still 

 more by .5." The species are arranged according to the compara- 

 tive injury as follows: 



Tree of heaven 3 



Ginkgo 3 



Red oak 2.5 



Scarlet oak 2.5 



Oriental plane 2.5 



American plane 2.5 



Tulip, or tulip poplar 2.5 



Sycamore maple 2 



Sugar maple 2 



Norway maple 2 



White pine 2 



Spruces 2 



White oak 2 



Burr oak 2 



Red maple 2 



Honey locust 2 



Catalpa 2 



European linden 1.5 



American linden 1.5 



Horse chestnut 1.5 



Buckeye 1.5 



Soft or silver maple 1.5 



American elm 1.5 



Hackberry 1.5 



Water or red elm 1.5 



European elm 1 



Scotch elm 1 



Cottonwood 5 



Carolina poplar 5 



Lombardy poplar 5 



Balm of Gilead 5 



Yellow locust 5 



Let it not be understood that the writer intends the preceding 

 list as the only guide to be consulted in the selection of trees for 

 planting, since the character of the soil, amount of space available, 

 scenic effects desired, as well as other points, should all be given 

 due consideration. He does intend, however, that it may serve as a 

 help in deciding what trees to use and what to avoid from the stand- 

 point of insect control, other factors being equal. 



Select healthy, vigorous trees for planting.— As intimated pre- 

 viously, the weakling of the lot, whether it be plant or animal, is 

 usually the first to be beset by parasites ; hence the selection of 

 rugged, vigorous planting stock is another of the basic laws of 

 shade-tree insect control. The transplanted, nursery-grown tree 

 as a usual thing has a better-developed root system and form than 

 the specimen taken from the woods, but care must be taken that the 

 nursery-grown tree is not a stunted specimen from a lot of over- 

 grown stock. Trees with withered, shrunken twigs or bark, with 



