476 BULLETIN 388 



of the block was not treated until April 13. In the meantime the borers 

 had begun feeding; in fact they bad been active since about the early 

 days of April. The results of the treatments in .this block are shown in 

 table 3 . 



It is seen from table 3 that practically absolute control was obtained 

 with the carbolineum treatment. Unfortunately for the experiment, the 

 entire check row did not show a high percentage of infestation, but it is 

 sufficient to indicate that the treatment was effective. 



TWO INFESTATIONS ALONG EDGE 

 OF TREATMENT 



In addition to the carbolineum, a high-grade creosote was tried in a 

 limited way. The creosote also gave perfect control, and this promises 

 well, for the row treated stood directly next to the check row. 



The carbolineum gave the bark of the trees a deep brown color but it 

 in no way affected their vigor. This brownish coloration gradually becomes 

 reduced during the summer, but treated trees can be recognized easily at 

 least three years after the treatment. 



