16 BULLETIN 833, U. S. DEPARTMENT OF AGRICULTURE. 
EXPERIMENT 2.—CONTROL OF EGGS BY MEANS OF DIPPING ENTIRE PLANT. 
The object of this experiment was practically synonymous with 
that of experiment 1 except that entire plants were used instead of 
cuttings as was the case in the previous test. 
Twelve plants on which newly laid eggs were present were divided 
into three lots, (a), (b), and (c), of four plants each. They were then 
treated as follows: 
(a) Four plants dipped in 40 per cent nicotine sulphate (1-500) plus laundry 
soap 1 ounce to 1 gallon of solution. 
(b) Four plants dipped in 40 per cent nicotine sulphate (1-800) plus laundry 
soap 1 ounce to 1 gallon of solution. 
(c) Four plants as check; no treatment. 
In each case the plants were constantly protected by covering them 
with an ordinary lantern globe, the free end of which was screened 
with a double layer of cheesecloth. The first dipping was done on 
March 29, while subsequent dippings were done on March 31 and April 
1,3,and8. Theplan was to treat them at least every 2 or 3 days fora 
week or 10 days. Observations were taken frequently on the effect 
of the treatment both on the plants and on the eggs. These obser- 
vations were continued until the close of the experiment, April 30, at 
which time the plants were uncovered and placed in the open green- 
house. 
Results —(a) Effect on plants: Slight burning was encountered 
with the 1-500 strength solution, but with the 1-800 solution no such 
trouble was evident. The check plants showed some sooty fungus 
which was probably due to the presence of honeydew secreted by 
aphids. (6) Effect oneggs: During the first few days the eggs showed 
normal development within the shell on the treated plants, but larve - 
failed to hatch from them, and no galls developed. On the check 
plants all of the eggs hatched successfully and many galls developed 
to maturity. 
Conclusions.—The expectations were fully confirmed by the re- 
sults obtained, as was the case in experiment 1. The checks devel- 
oped healthy and normal galls while in the treated plants further 
development was promptly arrested. From the economical point of 
view it is safe to say that nicotine sulphate (1-800) plus the soap will 
control the egg stage effectively if properly applied. 
TREATMENT OF BOTH CLEAN AND INFESTED CUTTINGS. 
The importance of having all new stock free and clean from the 
immature stages of the midge and of having the control at all times 
closely related to the propagation of stock has already been referred 
to. The above points were tested by the following experiment. 
This test consisted of three parts. Lots 1 and 2 were clean cut- 
tings, while lot 3 consisted of infested cuttings. Each lot was sub- 
