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Control. — The treatment of the pest is different according to 
whether the insect feeds on peas or on clover. 
Growers in the eastern United States and in Canada have found 
that early peas are practically exempt from injury, and therefore plant 
the early-maturing varieties when injury is probable. 
On peas grown for commercial purposes, spraying is too expen- 
sive, besides being in other respects impracticable, according to John- 
son's elaborate experiments in Maryland. Sanderson found, in Dela- 
ware, some little advantage in spraying while the lice are still confined 
to the terminals and the vines are as yet upright. 
A crop can be saved by the timely and thoro use of the "brush and 
cultivator" method devised by Johnson. This method requires that the 
peas be planted in rows 24 or 30 inches apart, instead of being sown 
broadcast. The lice are brushed off the vines with switches of pine 
branches or something similar, and are then buried under ground by 
means of a cultivator drawn by a single horse. Cultivation should not 
be repeated for three days, in order to insure the death of the buried 
lice. On a hot day, Johnson found that lice left on the surface of the 
ground died in a few minutes when the temperature of the air was 
94°-96° F., and that of the ground 115°- 119° F. In one instance, 600 
acres of peas were saved in this way; and tho forty men were neces- 
sary for two weeks to brush and cultivate the peas, the crop netted the 
owner 25,000 to 30,000 cases of peas of two dozen cans each. 
Instead of a cultivator a large shallow pan can be used, and the 
lice brushed into this as it is dragged between the rows by hand. In 
such a contrivance, containing a little water and kerosene, Johnson 
collected a bushel of lice to each row of 125 rods. The pan, made of 
galvanized iron, may be five or six inches deep, and as wide as the 
distance between the rows. Sanderson recommends this method as 
being perhaps the best one. It can be used when the soil is too damp 
for the cultivator. 
Sanderson states that high fertilization (as with crimson clover 
and lime), with frequent cultivation for several years, often enables a 
crop of peas to mature in spite of the louse. 
As the louse winters in the clover field and spreads from clover 
to peas, these should be planted as far from clover as possible. If the 
lice are abundant on clover in spring it may be advisable to plow the 
clover under, and roll the ground, in order to save the peas (Sander- 
son). 
In gardens the louse can be controlled on green peas and flow- 
ering sweet peas by spraying, as with whale-oil soap (1 pound to 5 
gallons of water) or kerosene-soap emulsion, diluted with 12 parts of 
water. Fletcher reports success with a spray of whale-oil soap and 
tobacco decoction. He put 10 pounds of tobacco leaves into half a 
barrel of water, strained off the liquid after a few hours, added 2 
pounds of whale-oil soap, and, when this was dissolved, added enough 
water to make 40 gallons. Two days after the application of this 
spray to both surfaces of the leaves most of the lice were dead, and 
