GRAPEVINE ROOT WORM 77 



extensive experiments with carbon bisulfid against this insect 

 and the summary of his results are as follows. He found that 

 the substance could not be used to advantage in soil that was 

 very dry or saturated with water, and that it must be used in 

 that which is damp. He states that the most satisfactory 

 results will probably follow its use in the spring, in a damp 

 soil, when it is applied in such a manner as to fumigate the 

 roots without the fluid coming in contact with them. He 

 recommends from 4 to 6 ounces for each vine and states that 

 it is not possible to kill every worm about each vine, and that it 

 is doubtful if the low price then current for fruit would justify 

 its use. Growers in the vicinity of Cleveland have not used 

 this insecticide to any extent since the time Professor Webster 

 made his experiments, and they give the high cost as the reason 

 for its not being adopted. It should also be added that con- 

 siderable care is necessary or the vines will be severely injured. 



Kerosene emulsion. Several writers have advised killing the 

 grubs at the base of the vines by the use of a kerosene emulsion, 

 which is to be washed to a greater depth by copious watering 

 or subsequent rain. We have seen very few cases where the 

 grubs were congregated sufficiently to warrant any attempt at 

 killing them in this manner and it hardly appears practical in a 

 large vineyard. 



Crude petroleum. It was hoped that it would be possible to 

 destroy the grubs of this pest by the application of this sub- 

 stance to the soil, and there seemed a chance of using it to 

 prevent the young larve making their way to the roots. Some 

 experiments in the office, however, demonstrated that the grubs 

 easily penetrated soil which had the surface layers moistened 

 by a fine spray of the oil, specially if placed on the soil 30 

 minutes to half a day or more after treatment. This substance 

 appears to have very little value in controlling this insect. 



Effect of calcium car bid refuse on grubs. Our attention was 

 called to this substance by the statement that it had proved 

 very valuable against the Phylloxera in France. Some of the 

 material was kindly sent us from the Union Carbide Company's 



