THE ROSE APHIS. 13 
On April 23, at a Virginia station near Washington, a number of 
large rosebushes trained on the side of a house and well infested with 
aphides were sprayed. Both winged and wingless forms of aphides 
were present. Nicotine sulphate was applied, with and without the 
use of soap as in the previous formula, at the rate of 1 part to 1,000 
of water. In the experiments without the use of soap some diffi- 
culty was found in obtaining a spreading action of the spray, and con- 
sequently only about 90 per cent of the aphides were reached. It is 
believed that all reached by the spray were killed. When nicotine 
sulphate was used at the rate of 1 part to 1,400 parts of water 
and 1 part to 1,500 parts of water, results were not satisfactory, only 
about 25 and 10 per cent, respectively, being destroyed. With the 
use of soap 100 per cent of the aphides on the vines were killed, the 
results being very satisfactory. At the rate of 1 part of nicotine 
sulphate to 1,400 of water with a laundry soap added, 90 per cent of 
the aphides were killed; whereas the results with nicotine sulphate 
at 1 part to 1,600 of water and 1 part to 1,800 of water in combination 
with soap were unsatisfactory, only 70 per cent and 50 per cent being 
killed. 
In these experiments a compressed-air sprayer with Bordeaux type 
of nozzle was used at an estimated pressure of 90 pounds, and a fine 
but driving spray was employed. The water used for the dilution of 
the insecticide was particularly soft, but contained a very small 
proportion of sulphur. 
From these experiments it may be concluded that nicotine sulphate 
at the higher dilutions as used in these experiments is much more 
effective against the rose aphis when used in combination with whale- 
oil or other soaps, since the spreading action thus induced is much 
more favorable. The plants may, however, be injured in case the 
spray solution is too strong. It is not believed that the injury shown 
in the experiments was caused by nicotine sulphate used at too great 
a strength, since it has been applied experimentally to roses in the 
greenhouse at the rate of 1 part nicotine sulphate to 15 parts of water 
without injury other than the appearance of mildew, undoubtedly 
superinduced by the spraying. It is apparent from the results 
obtained that a spray can not be employed weaker than 1 part of 40 
per cent nicotine sulphate to 1,400 parts of water with satisfactory 
results unless in combination with whale-oil or other soap. 
ARTIFICIAL CONTROL IN THE GARDEN. 
Experiments have been conducted against the rose aphis with 
different nicotine extracts under different conditions as to strength 
and weather. In no case, in the writer's experience, were the plants 
injured, whereas the insect was destroyed hi enormous numbers. 
The aphis is easily controlled by spraying with nicotine solutions 
