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stirring. The soap mixture should be allowed to stand 24 hours before 

 use. The above formula will make about 8 lb. of soap. In the ex- 

 periments mentioned in this paper, the commercial soap used was 

 " Caustic potash fish-oil soap No. 3." A table gives the cost of 50 U.S. 

 gallons (41"6 Impl.) of nicotine solution at the then current price, for 

 strengths varying from 1 : 457 to 1 : 3,000. Both the soap and the 

 nicotine should be diluted before mixing together, otherwise a white 

 precipitate is formed which clogs the nozzles. An alternative formula 

 is made up of whale-oil soap, 51b., in 50 U.S. gallons {iVQ Impl.). Spray- 

 ing should begin as soon as the Aphids have migrated from the clover 

 or other plants to peas. One of the difficulties in spraying is to reach 

 the individuals which have crawled in between the terminal leaves, 

 and as the first generation or two on the spring peas rarely feed in these 

 places, early spraying is the most effective. On a bright, clear day the 

 liquid dries more readily and is less likely to injure the plants. For 

 spraying peas, a two-wheeled cart, carrying a 50-gallon tank and a 

 good pump able to maintain 120 to 150 pounds pressure, with at least 

 nine nozzles, is probably the best. The wheels must have moderately 

 wide tyres and should be adjustable to suit the rows. The pump 

 should be run by adjustment to the axle. The pump used in 

 the experiments was able to develop 250 pounds pressure when in 

 good condition. The " Mistry Jr." and the " Simplex " nozzles gave 

 satisfaction, the spray being coarse enough to drive open the terminal 

 leaves and flower-clusters and yet fine enough not to gather in large 

 drops. The type of sprayer is illustrated : there are three nozzles 

 to each row ; one vertical, shooting a spray directly down on the row, 

 and two lateral, which throw a spray towards each side of the row. 

 The latter nozzles are placed at an angle slightly above the horizontal 

 plane, so that the spray will strike the under sides of the leaves. Using 

 an ordinary traction sprayer, not more than three rows can be dealt 

 with at once, as the pressure will be insufficient for satisfactory results. 

 Based on the whale-oil soap and Black-leaf 40 formula and on a machine 

 which will spray twelve acres per day, using six nozzles, and covering 

 two rows at the same time, the average cost of one application at the 

 rate of 75 U.S. gallons (62| Impl.) is about lis. 8d. per acre. If 100 

 U.S. gallons (83 Impl.) be used, this figure amounts to 15s. Id. With 

 the alternative formula, the costs for one appHcation are 3s. lid. and 

 4s. lid. respectively. Johnson {U.S. Bur. Entom., Bull., no. 26, N.S., 

 p. 57) has recommended the following method of control : On a day 

 when the sun is hot, with the thermometer above 90° F., the pea aphids 

 may be killed by knocking them off the plants with a pine branch, 

 following immediately between the rows with a cultivator. This covers 

 the insects with an inch or so of hot earth, having a temperature of 

 115-119° F., which is fatal to them. Even if the soil is not hot 

 enough to kill them at once, they will usually all be destroyed within 

 48 hours. This process should be repeated every third day for a fort- 

 night. In Virginia, this method has had some success where peas are 

 planted alone, but when planted with another crop it is abnost useless. 

 Clover, especially crimson clover, should not be planted near peas, but 

 if it is necessary to do so, the peas should be carefully examined every 

 day and as soon as aphids are noticed control must be effected. Highly 

 fertile land will help the crop to mature in spite of the attacks of 

 aphids. Early varieties are less liable to be seriously injured. 



