16 
BULLETIN 1040, U. S. DEPARTMENT OF AGRICULTURE. 
nozzles were used. Distillate-soap powder emulsion, soap powder, 
and water were used, as shown in Table 2, and data were gathered 
on the efficiency of the different solutions. 
Before the spraying started a man was sent through to remove 
the heavily infested bands, dip them in pure distillate, wring them 
out, and place them to one side to dry. 
Table 2. — Summary of spray operations against the citroph.il us mealybug. 
>pray. 
Total 
number 
of trees 
sprayed. 
Average 
number 
of trees 
per 
tank. 
Average 
spray 
time 
per 
tank. 
Average 
number 
of 
gallons 
per 
tree. 
Effective- 
ness of 
spray. 
5 per cent distillate-soap powder emulsion 
777 
69 
42 
59 
34 
42 
Min. 
58 
85 
45 
3.4 
5.7 
4.S 
Excellent. 
Water 
40 pounds soap to 200 gallons water 
Poor. 
Do. 
Both the water and soap-powder treatments were discontinued, as 
it was found to be impractical in application to get a thorough clean- 
up of the egg masses. The distillate-soap emulsion was quicker in 
application and more effective. 
The bands were replaced shortly after the completion of the spray 
work, and field observations made from time to time throughout the 
following year. Though some mealybugs appeared under the bands 
following the spraying, they were completely controlled by natural 
enemies and required no further treatment. Throughout the fall and 
winter no mealybugs were apparent, and in the spring of 1920 so few 
mealybugs appeared under the bands that hand treatment was all that 
was required. The grove is now commercially clean, and there has 
been a marked increase in the grade of the fruit. 
The data obtained in this experiment not only demonstrated the 
practicability and efficiency of the distillate-soap emulsion but also 
demonstrated the advisability of proper pruning before spraying. 
The trees on this grove were low on the ground and it was difficult 
to treat the trunks owing to low branching and inside growth. In 
consequence of this condition it took much more material and a longer 
time to make the application. The cost of spraying was as follows : 
Removing and dipping bands, 1 man, 1 day $3. 00 
16^ tanks spray : 
330 pounds soap powder, at $0.07 per pound 23. 10 
165 gallons distillate, at $0.07 per gallon 11.55 
Two men, at $4 per day, 2 days 16. 00 
Team, at $4 per day, 2 days 8. 00 
Gasoline and oil, 2 days 2 50 
Total 64. 15 
Cost of $0,072 per tree. 
