30 
THE HOP APHIS IX THE PACIFIC REGION. 
QUASSIA EFFECTIVE ONLY BY CONTACT. 
There is an erroneous impression among some growers that the 
quassia spray after it has dried upon the leaves will kill the aphides 
which later appear upon them. The quassia, as well as the other 
sprays used for the hop aphis, is effective only when in actual contact 
with the insects. 
EFFECT OF SPRAY MATERIALS UPON THE QUALITY OF SPRAYED HOPS. 
It was suggested by some growers that nicotine sulphate, whale- 
oil soap, and quassia extract might injure the quality of the hops on 
which they were applied. In order to test this point some nearly 
ripe hops were sprayed with the following materials, and when the 
crop was being picked these sprayed hops were picked, dried in the 
kiln with the other hops, and later sent to Washington for analysis: 
Nicotine sulphate, 1-1,000; whale-oil soap. 4 pounds to 100 gallons. 
Nicotine sulphate, 1-2,000; whale-oil soap, 8 pounds to 150 gallons. 
Nicotine sulphate, 1-3,000; whale-oil soap, 4 pounds to 100 gallons. 
Blackleaf tobacco extract, 1-60 and 1-75, each with 2 pounds of whale-oil soap to 
100 gallons. 
Quassia chips, 7 J pounds; whale-oil soap. 9 pounds to 250 gallons. 
The following analyses were received from the Bureau of Chemistry: 
Table VIII. — Analyses of hops sprayed with various insecticides. 
No. 
Whale-oil 
soap. 
Nicotine. 
1 
2 
3 
4 
6 
6 
None. 
None. 
None. 
None. 
None. 
None. 
None. 
None. 
None. 
None. 
None. 
None. 
The quassia was not tested for, as there is no test that is applicable. 
From the above analyses it is evident that the nicotine or whale-oil 
soap that remained upon the hop cones was not present in sufficient- 
quantities to be detected by a chemical analysis, and therefore would 
not injure the quality of the hops. 
The flour paste is composed of starch and gluten, which has no 
distinct flavor or odor, and even through it were present in large 
amounts it can not be conceived how this material could influence 
the quality of the hops. 
DIRECTION IN WHICH TO WORK. 
Since the winged aphides travel largely with the wind, the best 
results will be obtained, especially where the winds are prevailingly 
from one direction, by working with the wind. If this is done the 
