GARDEN 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 emploj^ed 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 kerosene 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, Sh gallons of water added to 1 gallon of stock solution. 
10 per cent strength, 5f 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 following results were recorded : The 7 
per cent kerosene emulsion was very effective 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 $1.20, 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 ba a ton per acre 
under normal conditions, and since spraying with kerosene emulsion 
as described costs pproximately $1.20 per acre and effects an almost 
complete saving i the crop, the market price of which has been $20 
per ton, this t atment may be 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 
