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over the kerosene, these would be instantly killed. I think that the 
same method would be effective in the strawberry fields as well, 
unless this beating of the plants should interfere to some extent 
with fertilization. 
Pyrethrum. As far as topical applications are concerned, I am 
able to report that we have in pyrethrum a perfectly effective 
agent, which has at the same time the inestimable advantage, to 
the strawberry grower, of being wholly harmless to the plant and to 
the consumer of the fruit. Recognizing the fact that this 
was almost the only substance at all likely to prove useful 
which it was permissible to apply to strawberries while in 
fruit, I began to experiment with pyrethrum the first day of my 
visit to Southern Llinois, in May. Some plant bugs of all ages, 
exposed in a vial to a little powdered pyrethrum, began to show its 
effects in four minutes, by tumbling and sprawling about on their 
backs and sides, both old and young being equally disturbed. In 
nine minutes some of the youngest were helpless and unable to 
walk, and in two more minutes nearly all but two were on their 
backs, the youngest motionless, the others feebly struggling. In two 
hours all were motionless or helpless, except one pupa, which was 
reviving. This last finally recovered and escaped, but the others alk 
finally perished. 
Some additional experiments, made at the Laboratory this fall, 
were still more conclusive. Twenty-one adults were confined under 
a bell glass and dusted with a mixture of one part of powdered 
pyrethrum to ten parts of flour, at 8:0 A. M., November 5, and at 
11:45 only two were active, the others being but feebly alive. At 
1:30 all were on their backs, showing signs of life only by a slow 
action of their legs. In 24 hours three or four were feebly alive, 
and the remainder dead; while in 48 hours all were dead. 
Several trials were made with pyrethrum suspended in water, of 
which the following is a fair sample: Thirty-five adults were 
sprinkled with water containing powdered pyrethrum in the ratio of 
15 grains to the pint, at 11:05 A. M., November 8. At 12 M. nearly 
all were lying on their backs, strongly affected; at 6:45 in the 
evening, only eight were at all active, and the next morning but 
three were able to keep their feet. On the afternoon of the 9th, all 
were dead but four, and these succumbed during the night. 
Trial was next made of both the flour and the water mixtures, 
to test the supposition that the confinement of the insects had 
increased the efficiency of the pyrethrum in the above experiments. 
Twenty of the bugs were thoroughly treated with water in which 
twenty grains of pyrethrum to the pint had been shaken up, and 
the insects were then enclosed in a netting bag and exposed to the 
air. In an hour all were helpless, the greater number being appar- 
ently dead. Four hours after the treatment, five were feebly moving 
their legs, but made no attempt to walk, the fifteen remaining being 
all apparently dead. In twenty-four hours all were dead but two, 
and these perished a few hours later. 
At the same time one part of pyrethrum powder was mixed with 
ten parts flour, and sprinkled upon twenty adults which were then 
