472 



BULLETIN 388 



ber i, 1913, a part of this block was treated with scalecide at varying 

 strengths, and a few trees were treated with carbolineum and its emulsion, 1 

 as indicated in table i . This experiment was closely watched the following 

 spring, but no injury to the trees could be noted except that the carbolin- 

 eum-treated trees did not seem so vigorous as the others. However, 

 they grew, and in 1916 they were large, healthy trees. Examination and 

 careful count of the burrows in all the trees was made on June 17, 19 T 4. 

 The infestation is shown in table i : 



TABLE i. RESULTS OF EXPERIMENTS OF 1913-14 



* All dilutions of scalecide are with water. 



In the spring of 1914 a series of experiments was undertaken in a large 

 nursery. Stock three years old was chosen, as it was the most readily 

 available at the time. Badly infested trees were selected at one side of a 

 large block which had been recently dug. Directly across the roadway 

 was a block of young poplars. On March 3 1 , scalecide at varying strengths, 

 carbolineum, and carbolineum emulsion were applied to the trunks from 

 the ground up to the young growth. The day was fair, but rain began 

 to fall before the various treatments were completed. However, the rain- 

 fall was slight, so that it should have had no effect on the insect icidal 

 qualities of the preparations. 



The treated trees were examined carefully on May 14, 1914. The 

 various treatments had no effect on the growth of the trees, every tree 

 growing vigorously and there being no difference, as far as could be 

 detected, between the checks and the trees under experimentation. In 

 the checks the larvae were actively at work and their abundance was 



1 The carbolineum emulsion was prepared by dissolving i pound of sodium carbonate in i quart of 

 hot water, adding i quart of carbolineum, and stirring the mixture vigorously. 



