26 THE HOP APHIS IN THE PACIFIC EEGION. 
Table VI represents the work done in Oregon by Mr. H. N. Orel 
and is in part a repetition of the results recorded in Table V. It 
also contains data upon tobacco waste, which appears very satisfac- 
tory and very cheap. If the decoction is allowed to boil or the tobacco 
happens to be low in nicotine, the spray will not be effective, and the 
vines will have to be resprayed. 
If this material be used each tankful should be tested upon some 
aphides and a record of efficiency kept. It is for these reasons not so 
satisfactory as a material containing a known quantity of insecticide. 
Nicotine-sulphate formulas for 100-gallon lots. 
Ounces. 
Nicotine sulphate, 1 to 1,000 13 
Nicotine sulphate, 1 to 2,000 6£ 
Nicotine sulphate, 1 to 2,500 51. 
Nicotine sulphate, 1 to 3,000 , 4£ 
The formula " 4-100," given for flour paste, means 4 gallons of 
flour paste (made according to directions) to each 100 gallons of spray. 
This paste contains 1 pound of flour in each gallon, so that there 
would be 4 pounds of flour (in the form of paste) in each 100 gallons 
of spray. 
The formula "4-100," when referring to whale-oil soap, means 4 
pounds of whale-oil soap to 100 gallons of spray. 
Flour paste had proved to be a most efficient, cheap, and convenient 
spreader for the lime-sulphur solutions. 1 Some experiments were 
conducted during 1912 with this material in combination with nico- 
tine sulphate against the hop aphis. Table VII gives some of the 
results obtained with this mixture. 
Table VII. — Experiments in the control of the hop aphis by sprays of nicotine sulphate 
and flour paste. 
Formula. 
Number 
of 
Per cent 
aphides 
killed. 
present. 
627 
100 
611 
100 
1,668 
99 
148 
99 
308 
100 
271 
96 
Cost per 
100 
gallons. 
Nicotine sulphate, 1-2,000: flour paste, 4-100 
Nicotine sulphate, 1-2.500; flour paste, 4-100 
Nicotine sulphate, 1-3,000; flour paste, 4-100 1, 668 99 .50 
Do 148 99 .50 
Nicotine sulphate, 1-3,500; flour paste, 4-100 308 100 .45 
Nicotine sulphate, 1-4,000; flour paste, 4-100 271 96 .40 
From the results noted in the preceding tables it is evident that 
nicotine sulphate is effective in dilutions as high as 1-3,500, and that 
flour paste, 4-100, is an effective spreader for this material. The 
nicotine sulphate, 1-4,000, was not quite so effective, and it was also 
observed that its action was so slow that the sprayed aphides were 
able to deposit young on the leaves, thus reinfesting the hopvines. 
See Bulletin No. 117 and Circular No 166 of this bureau. 
