68 
THE GRAPE ROOT-WORM. 
In view of the results described above, there can be no doubt as 
to the value of a poison as a direct and effective killing agent of the 
beetles in the open field. It is quite possible, moreover, that the 
rapid removal of dead bodies by ants and other agencies and the 
close search required to find them on account of the fact that their 
color is the same as that of the soil, and also by the fact that they 
were distributed over a large area on the foliage of full-grown vines, 
have resulted in the failure of other workers to find a sufficient num- 
ber of dead bodies of beetles in sprayed vineyards to warrant them 
in feeling that this method of control is as effective as might be 
desired. 
COMPARATIVE EFFECTIVENESS OF ARSENATE OF LEAD AND 
ARSENITE OF LIME. 
In our field work with arsenical sprays, planned for a period of 
two or three seasons, arsenate of lead was the insecticide used 
throughout the experiments. Since, however, many vineyardists 
were using arsenite of lime when this investigation commenced, it 
was deemed advisable to make a test of its efficiency as an insecti- 
cide against the grape root-worm beetle as compared with arsenate 
of lead. 
In the summer of 1907 a test of these two insecticides was made 
in two vineyards in different parts of the township of North East. 
One vineyard of about 8 acres belonging to Mr. W. S. Wheeler was 
divided into three plats. Two plats of about 3 acres each were 
sprayed, one with Bordeaux mixture and arsenate of lead and the 
other with Bordeaux mixture and arsenite of lime. The third plat 
of about 2 acres running through the middle of the block was left 
unsprayed. Two spray applications were made on these plats at 
the same dates, July 9 and July 27, with a gasoline-engine power 
sprayer (PI. X, fig. 2). The spray was applied at a pressure of about 
100 pounds, and about 100 gallons of the liquid were used per acre. 
The formula used on the plat sprayed with arsenite of lime was, 
copper sulphate, 5 pounds; lime, 6 pounds; resin-fishoil soap, 2 
pounds, and 1 quart arsenite of lime made according to Kedzie's 
formula (containing 4 ounces of white arsenic) to 50 gallons of water. 
The resin-fishoil soap was added to increase the mixture's property 
of adhering to the foliage. The formula used on the plat sprayed 
with arsenate of lead was, copper sulphate, 5 pounds; lime, 5 pounds; 
arsenate of lead, 3 pounds; and water, 50 gallons. The effect of these 
treatments in preventing egg deposition is shown by a count of the 
egg clusters on 25 vines in each of the three plats. It should be 
stated in addition that at the time of making the count of egg depo- 
sition there was evidence of a great deal more feeding by beetles on 
the foliage on the plat treated with arsenite of lime than upon the 
