GAEDEN FLEA-HOPPER IN ALFALFA. 25 



ounce of the potassium sulphid to 5 gallons of water, a hand sprayer 

 of the compressed-air type being used. The plat was thoroughly 

 sprayed in the morning and also at midday, but even when a stronger 

 solution was employed there was little appreciable benefit from the 

 application. 



A spray of kerosene emulsion was next tried on three experimental 

 plats of alfalfa, each having an area of 100 square feet. The alfalfa 

 had been cut and removed a few days before, and the moist weather 

 was causing the new crop to grow rapidly. The stock emulsion was 

 prepared by the following method: One-half pound of laundry soap 

 was dissolved in 1 gallon of hot water; the solution was then removed 

 from the fire, and after 2 gallons of kerosenie had been added the 

 material was violently agitated. The table of strengths, as applied 

 in their order on the three plats, follows: 



7 per cent strength, 8 J gallons of water added to 1 gallon of stock solution. 

 10 per cent strength, 5§ gallons of water added to 1 gallon of stock solution. 

 12 per cent strength, 4\ gallons of water added to 1 gallon of stock solution. 



Observations were continued for one day after the spraying experi- 

 ments were started, and the follo\ving results were recorded: The 7 

 per cent kerosene emulsion was very eft'ective in destroying the 

 garden flea-hopper in all stages; the 10 per cent solution killed 

 practically all the flea-hoppers and did not materially affect the 

 alfalfa; the 12 per cent solution destroyed all of the insects but 

 damaged the alfalfa crop noticeably. 



In the campaign against the garden flea-hopper about 12 acres of 

 fields where the most severe outbreaks occurred were sprayed with 

 10 per cent kerosene emulsion with great success. The solution was 

 applied with an orchard power sprayer having two nozzles, the spray 

 being delivered from the machine at a gauge pressure of 80 pounds 

 and covering a strip 18 feet wide. The machine was driven by a team 

 of mules, and the nozzles were operated by two men at the rear of the 

 machine. An average of 30 gallons was applied, to each acre. The 

 cost per gallon of the solution was about -4 cents, thus making the 

 estimated cost per acre SI. 20, nothing being added for labor and 

 machinery, since the farmers had these at their immediate disposal. 

 Since it was estimated that the yield of hay would be a ton per acre 

 under normal conditions, and since spraying with kerosene emulsion 

 as described costs approximately SI. 20 per acre and ofl'ects an almost 

 complete saving of the crop, the market price of which has been S20 

 per ton, this treatment may bo recommended as a satisfactory and 

 economical measure of control. 



The only other method of control which effectively overcame the 

 pest was the plowing under of the infested crop, which was done in 

 a number of cases where many of the plants had been killed by the 



