]N"ew York Agricultural Experiment Station. 335 



Experiments in 1S96. — As shown in the table, the plats were 

 sprayed but twice in 1896. Unfavorable weather prevented a 

 third spraying until too late to be practicable and the machines for 

 catching the beetles were used twice, about seven days apart, after 

 the last spraying. For these experiments a knapsack sprayer was 

 used to apply the poison. When lime was used, enough of the 

 freshly-slaked lime was added to make the mixture slightly milky 

 in appearance. 



Results in 1896. — It was difficult to obtain exact results in 

 this case. Swarms of beetles came from other fields to the 

 sprayed plats. The general indications were that the plats 

 sprayed with green arsenite mixed with lime water and glue and 

 with arsenate of lead and glue were less injured after the second 

 spraying than the other plats. About 80 per cent of the willows 

 on these plats were uninjured by the beetles, while on Plat III, 

 the. check plat, at least 50 per cent were damaged. Glucose did 

 not prove as successful in making the mixture adhere to the leaves 

 as thin glue, but glue was found to be impractical for this purpose 

 because of sticking in the pump and clogging the nozzle. 



Experiments in 1897. — The plan of the experimental field was 

 changed for these experiments and a Peppier horse power sprayer 

 used in place of a knapsack. As shown by the diagram the acre 

 was divided into two equal plats and both plats sprayed on June 3. 6 

 The machine for catching the insects was not used on either plat. 

 Plat II received but one application of the poison while Plat I 

 was sprayed as shown in the following diagram. 



The green arsenite was used at the strength of 1 pound to 100 

 gallons of lime water. Whale oil soap, 1 pound to 20 gallons of 

 the mixture, was added to make it spread upon the leaves. Whale 

 oil soap also doubtless acts as a repellant to the insects and may 

 be used much stronger. 



6 The original plan was to leave flat II unsprayed but through a misunder- 

 standing it received one application of the poison. 



