Report of the Entomologists. 537 



Experiment No. 2. 



Under this head may be grouped several experiments all of 

 which had the same object in view, namely, to determine the eflQ- 

 ciency of the green arsenite as a poison for some of the more 

 common leaf eating insect pests. The first experiment consisted 

 of three applications to basket willows infested with the cotton- 

 wood leaf beetle. These applications were made at Liverpool, 

 N. Y., on May 18, June 5 and June 9. The plot sprayed con- 

 sisted of about one-fourth of an acre, the green arsenite being 

 used in each case at the ratio of one pound of the poison toi 150 

 gallons of water. Sufficient lime was added to the mixture to 

 make it slightly milky. The first two applications were made 

 with a power sprayer, which, unfortunately, did not do satisfac- 

 tory work, especially in the first instance. The third application 

 was made with a knapsack sprayer. Considerable difficulty was 

 experienced in making the mixture adhere to the leaves. Glucose 

 was finally added at the rate of two quarts to 45 gallons, but it 

 did not have the desired effect. 



These applications can not be considered an entirely satisfac- 

 tory test as to the efficiency of green arsenite when used against 

 the cotton-wood leaf beetle, owing to the failure in making the 

 first application thorough, and also the difficulty in making the 

 mixture adhere to the leaves. However, the results were suffi- 

 cient to show that, when properly applied, the green arsenite 

 is an effectual poison for this insect. As a further test, 

 Mr. Joseph Kennedy, of Liverpool, on whose farm the experiments 

 were made, dipped some willow leaves in the poison and placed 

 them in a breeding cage with a number of the beetles. It was 

 observed that all the beetles, about thirty in number, which fed on 

 die leaves, were dead very soon after. 



The second experiment consisted of spraying two plots of nur- 

 sery stock which was being attacked by a species of flea beetle. 

 Plot 1 consisted of about three acres of one-year-old apple 

 grafts. Plot 2 consisted of about three acres of two-year-old 

 apple and pear stock. Both plots were very badly infested. 



