New York Agricultural Experiment Station. 465 



instance, but proved fully as effectual as the stronger solution in 

 killing the lice. These treated trees were not seriously infested 

 again during the season. 



Conclusions. — The above experiments indicate that, when young 

 nursery trees become so badly infested with plant lice as to make 

 spraying impractical, they may be successfully treated by dipping 

 the curled tips in a solution of whale-oil soap, one pound to seven 

 gallons of water. The expense and labor were so slight as to be 

 factors of but little importance. When thoroughly done but one 

 treatment is necessary under ordinary circumstances. 



Spraying Young Grab^ts. 



Most of these experiments were conducted against a large 

 species of flea-beetle, Si/stena hudsonias Forst. The beetles were 

 very abundant during June and July on apple and pear grafts in 

 a nursery near the Station. The beetles fed voraciously on both 

 upper and under surfaces of the leaves, eating away the tender 

 tissue and causing them to wither and die. About twenty-five per 

 cent of the grafts were killed before the experiments were com- 

 menced, and a whole block of 20,000 apple grafts was seriously 

 threatened. The beetles were also doing serious injury in a small 

 block of two-year-old apples and a large block of two-year-old 

 pears in the same nursery. Green areenite was used in all the 

 experiments, and in each case sufiicient lime was used to make 

 the mixture " milky " in appearance. A barrel and pump, 

 mounted on a small stone boat which could be easily hauled be- 

 tween the rows by one horse, was used. To each lead of hose a 

 V was attached so as to support two short lengths of hose. Two 

 men followed the pump, spraying two rows at a time, thus requir- 

 ing three men to do the work. Improved Vermorel nozzles were 

 used. 



Experiments. — Block 1; one-j-ear-old apple grafts sprayed June 

 16, with green arsenite, 1 pound to 150 gallons of water. June 18 

 this block was again sprayed, but the poison was used at a 

 strength of one pound to 100 galloiis of water. June 25 a third 

 application was made, the poison being used at the same strength. 

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