CONTROL OF THE HOP APHIS. 
25 
show the results of these experiments and give the cost of the mate- 
rials per 100 gallons of spray: 
Table V. — Results of spraying experiments for the hop aphis, ivith costs of materials 
per 100 gallons of spray. 
Experi- 
ment 
No. 
Materials used. 
Pressure. 
Number 
of 
aphides. 
Per cent 
killed. 
Date 
sprayed. 
Date 
counted. 
Cost per 
100 gal- 
lons. 
Pounds. 
1 
Nicotine sulphate, 1 to 3,000 
80-100 
1,227 
99.9 
June 15 
June 17 
SO. 416 
2 
Nicotine sulphate, 1 to 2,000 
.. 80-100 
1,005 
97.8 
June 13 
...do 
.62 
3 
Nicotine sulphate, 1 to 3,000; 
whale-oil soap, 4 to 100. 
80-100 
3,089 
99.2 
June 14 
...do 
.80 
4 
Nicotine sulphate, 1 to 3,000; 
cresolsoap, 1 to 300. 
80-100 
1,990 
95 
June 15 
...do 
.83 
5 
do 
80-100 
3,474 
84 
...do 
...do 
.83 
6 
80-100 
1.810 
94 
..do 
.do 
.86 
7 
Nicotine sulphate, 1 to 2,000; 
cresol soap, 1 to 300. 
80-100 
2.320 
97 
...do 
...do 
1.04 
8 
Blackleaf tobacco, 1 to 60 
80-100 
2.590 
99.8 
...do 
...do 
1.08 
9 
Nicotine sulphate, 1 to 1,000 
80-100 
654 
98.2 
June 13 
...do 
1.25 
10 
Nicotine sulphate, 1 to 2,000; lye- 
resin soaps. 
80-100 
2.225 
99.1 
June 15 
...do 
1.37 
11 
Nicotine sulphate, 1 to 1,000; 
whale-oil soap, 4 to 100. 
80-100 
2,512 
99.4 
June 14 
...do 
1.42 
12 
Nicotine sulphate, 1 to 1,000; 
80-100 
2.780 
99 
June 15 
...do 
1.67 
cresol soap, 1 to 300. 
INEFFECTIVE MATERIALS. 
Limesulphate, 36° Baume, 1 to 86. 
Cresol soap, 1 to 300 
80-100 
1,950 
14 
June 16 
June 19 
80-100 
129 

June 13 
June 16 
SO. 24 
.42 
From the data in Table V it is evident that all the experiments 
except Nos. 5, 13, and 14 were quite satisfactory and that Nos. 1, 
2, 3, and 4 were the cheapest materials to use. It was found that 
the nicotine sulphate without soap did not spread very readily and 
that the good results obtained were clue to the very careful applica- 
tion. Either flour paste or soap should always be used with the nico- 
tine solutions. 
Table VI. — Spraying experiments conducted in Oregon against the hop aphis during 1911. 
£1 
Materials used. 
Pressure. 
Number 
of 
aphides. 
Pounds. 
100 
213 
100 
253 
100 
695 
100 
100 
529 
73 
100 
100 
491 
130 
Per cent Date 
killed. ; sprayed. 
Date 
counted. 
Cost per 
100 
gallons. 
Tobacco waste, 25 pounds to 100 
gallons water. 
Tobacco waste, 27J pounds to 100 
gallons water. 
Nicotine sulphate, 1 to 2.000 
Nicotine sulphate, 1 to 2,000; whale- 
oil soap, 5 to 100 
Nicotine sulphate, 1 to 1,000 
Nicotine sulphate, 1 to 2,000; whale- 
oil soap, 5 pounds to 100 gallons 
water 
Nicotine sulphate, 1 to 750 
100 Aug. 22 
100 ...do 
89 Aug. 21 
98 ...do 
100 ...do 
Aug. 25 
Aug. 24 
Aug. 23 
..do.... 
..do 
...do do. 
Aug. 22 | Aug. 25 
$0.18 
.20 
.62 
.845 
1.25 
1.475 
1.66 
