30 
THE RED SPIDER OX HOPS IN CALIFORNIA. 
COST OF SPRAYING. 
The following estimate of the cost of spraying for the red spider is 
made from data taken from actual field work on high-trellis yards. 
The amount of material needed for hops on short poles will be some- 
what less. 
It has been found that one machine will spray from 2 to 3 acres 
per day and that in order to do thorough work it is necessary to apply 
from 300 to 500 gallons per acre, according to the amount of foliage 
on the vines. The following data are based on a machine winch will 
spray 2 acres per day. 
Table IX. — Cost of spraying hopyards for the red spider. 
Cost of application per acre. 
Flour paste, 8-100; 
cost and cooking, 
19 cents per 100 
gallons. 
Lime sulphur, 1-100, 
and flour paste, 
4-100: cost per 100 
gallons, 26 cents. 
300 
gallons. 
500 
gallons. 
300 
gallons. 
500 
gallons. 
Labor: 3 men at $2 per dav for one-half day 
SO. 57 
3.00 
.25 
$0.95 
3.00 
.25 
SO. 78 
3.00 
.25 
SI. 30 
3.00 
.25 
Total cost 
3.82 
4.20 
4.03 
4.55 
Cost of two applications 
7.64 
8.40 
8.06 
9.10 
The cost of stripping the vines preliminary to spraying will be 
from $1.80 to $2 per acre. 
Comparing the cost of spraying for the red spider with the loss 
that may result from its ravages, it is evident that money spent in 
controlling this mite will be well invested. 
CULTURAL METHODS. 
Stripping the vines. — The practice of stripping the vines is a common 
one in regions where the hop aphis (Phorodon humuli Schrank) is 
troublesome. A large amount of aphis-breeding foliage is cleared 
from the vines and only the more readily sprayed leaves are left. 
In experimenting along this line several vines were stripped and 
tied together at various points to determine which method would 
most readily facilitate spraying. The lower foliage on vines which 
were not stripped but were tied together 4 feet from the ground 
(fig. 7) was found to be matted and very difficult to spray thoroughly. 
When the lower 3 feet of the vines were stripped and the two vines 
tied at the 4-foot mark (fig. 8), 1 foot of the vine was still in a condi- 
tion difficult to spray. But when stripped and tied a few inches 
below the lower leaves (fig. 9), the vines spread out nicely and the 
