INSECT PESTS OF OHIO SHADE AND FOREST TREES 175 



INTENSIVE CONTROL MEASURES RARELY POSSIBLE UNDER 

 FOREST OR WOODLOT CONDITIONS 



While the execution of measures for the control of noxious 

 insect pests infesting city trees is highly practicable and to a some- 

 what less degree in the care of shade and ornamentals in the coun- 

 try, the exact reverse is true when we consider the artificial control 

 of insect scourges in the average Ohio woodlot or timber tract. 

 Timber values at present do not justify the expense involved in the 

 enterprise. As an example of the latter condition, the recent 

 scourge of oyster shell bark louse in the ash woodlots of Geauga 

 and Ashtabula Counties may be cited. A few years ago this insect 

 obtained a firm foothold on ash in the northeastern section of the 

 State and was especially prevalent in the two counties named. 

 Hundreds of magnificent trees were killed outright and much cut- 

 ting was done on account of the trees being severely infested, which 

 o'therwise would have been delayed a number of years. It was 

 entirely impracticable to spray (see Plate VI, Fig. 1) on account of 

 the size of the trees and the expense of adequate machinery and the 

 necessary materials the work would have required; hence nothing 

 was to be done but let the scourge take its course. Fortunately, 

 the crest of the attack passed after two or three seasons of severe 

 injury and the natural enemies overtook the scale and subdued it, 

 but not until injury amounting to many thousands of dollars had 

 been done. 



On the other hand, the control of insect scourges in woodlands 

 is sometimes practicable, as demonstrated in some sections of New 

 England, where annual spraying is practiced for the control of the 

 gipsy and brown tail moths. Where the work is well organized 

 and the proper equipment is at hand, not only can insect outbreaks 

 be controlled under such conditions but the expense of the procedure 

 is much less than one might suppose. (See Plate XIII, Fig. 2.) 

 Under New England conditions both the material and the esthetic 

 values of the woodlands are combined to make the enterprise prac- 

 ticable, but as matters stand at present in Ohio, the sprayng of 

 woodlands is not practicable, especially in those sections of the State 

 where land values are extremely low. 



ESTABLISHING A MUNICIPAL TREE-TREATING DEPARTMENT 



INSECT CONTROL IN CITIES A MUNICIPAL PROBLEM 



The application of insecticidal measures is a difficult task under 

 most city conditions, especially if the various householders attempt 

 the operation individually. It is usually the case that a few trees 



