CONTROL OF THE HOP APHIS. 
31 
winged aphides will not be able to migrate to the sprayed hops so 
readily as if the wind were blowing from the unsprayed hopvines to 
those which have been sprayed. 
CONTROL OX PRUNE. 
The hop aphis apparently is capable of migrating some distance, 
provided the wind is right, and in prune-growing sections it is impos- 
sible to kill all of the migratory insects. Where there are only a 
few prune or plum trees in the neighborhood, however, the destruc- 
tion of any nonproductive trees and any wild plums that may be 
present will reduce the number of trees that will have to be sprayed. 
The spraying of the plums and prunes can not be relied upon for 
the control of the hop aphis, but where it is thoroughly and systemat- 
ically done the severity of the season's infestation may be greatly 
lessened. Work along this line is strongly recommended. 
FIELD OBSERVATIONS. 
About the time that the aphides are expected to appear upon the 
plum or hop it is advisable to go through the prune orchards or hop- 
yards and note the conditions. Careful observations, if maintained 
throughout the season, will keep the grower informed as to the 
severity of the infestation in all parts of his hopyards. He will then 
be able to check the infestation before any serious damage has been 
done. 
SPRAYING REPORT. 
The following form of a daily report was successfully used by Mr. 
H. N. Ord at Independence, Oreg., in 1912, to keep a record of the 
spraying operations in the field : 
Date. 
No. acres 
infested. 
No. acres 
sprayed. 
No. gallons 
used. 
Formula 
and cost 
per 100 
gallons. 
Effective- 
ness of 
spray ap- 
plied "three 
days before. 
No. 
machines 
used. 
No. acres 
sprayed per 
machine. 
Cost of 
operations 
per acre. 
. 

i 
If such a report is faithfully kept the grower will always know the 
condition of his hopyard and what his spraying operations are costing 
him. 
SPRAYING MACHINERY. 
Several forms of outfits may be successfully employed in the hop- 
yards provided that they meet the following requirements: The 
machine should have a tank capacity of from 75 to 200 gallons, 
