40 
PAPERS ON INSECTS AFFECTING VEGETABLES. 
September 15 the application was repeated. The older leaves were 
still well coated with the poison from the first dose, but many new 
leaves had been put out and these were unprotected. All were com- 
pletely coated by the second spraying. At this date there were oc- 
casional dead larva?, but they were not common. 
September 16 it was noted that some of the larvae were actually 
entering the bud and that very few of them had been killed. 
Heavy showers occurred September 18, 19, and 20, but the coat of 
poison remained fairly good. At this latter date, most of the larva? 
were in flourishing condition, and the experiment was considered a 
failure. The plants were slightly burned, but no serious damage re- 
sulted. One interesting point brought out by this experiment is that 
the mixture was remarkably adhesive and not readily washed from 
the foliage by rains. 
Experiment No. o. — Arsenate of lead, 5 pounds, and whale-oil 
soap, 10 pounds, in 100 gallons of water. 
October 12, 418 good-sized cabbage plants were sprayed. The 
larvae were moderately common. All were deeply buried and ob- 
viously beyond the reach of the poison. The mixture adhered well 
and the plants were completely coated. These plants were examined 
daily until October 19, but not a dead larva was found, and at that 
date the experiment was abandoned as a complete failure. The 
mixture did not burn the foliage. 
Experiment No. If. — Paris green, 2 pounds, whale-oil soap, 8 
pounds, and nicotine sulphate, 25 ounces, in 100 gallons of water. 
November 10, 410 good-sized moderately infested plants were 
sprayed. These plants were kept under almost daily observation 
until November 23, but not a dead larva was found. This mixture 
did not burn the plants, and it completely wiped out plant-lice 
(aphides) and several species of lepidopterous larva? which were 
exposed on the leaves. It was, however, ineffective against the well- 
protected Hellula larva?. 
The experiments with insecticides may be summarized as follows: 
Experi- 
ment 
No. 
Date. 
- Insecticide used. 
Effect on 
larvae. 
Injury to 
foliage. 
Remarks. 
1910. 
1 
Sept. 7 
Paris green, 2 pounds, and 
Ineffective. . 
Not worth 
A few larvae, in folded 
whale-oil soap, 8 pounds, 
mention- 
leaves, on small cabbage 
in 100 gallons of water. 
ing. 
plants were killed. None 
were killed on large 
plants. 
2 
Sept. 12 
Paris green, 5 pounds, lime, 
5 pounds, and whale-oil 
soap, 10 pounds, in 100 
gallons of water. 
do 
do 
A few larvae, in folded 
leaves, on small cabbage 
plants were killed. 
3 
Oct. 12 
Arsenate of lead, 5 pounds, 
and whale-oil soap, 10 
pounds, in 100 gallons of 
water. 
do 
None 
Applied to large cabbage 
plants. No larvae were 
killed. 
4 
Nov. 10 
Paris green, 2 pounds, whale- 
oil soap, 8 pounds, and 
nicotine sulphate, 25 
ounces, in 100 gallons of 
water. 
do 
do 
Do. 
