14 
BULLETIN 1178, U. S. DEPARTMENT OF AGRICULTURE. 
Table 4. — Number of rust mites founa per square inch at different times on plats sprayed 
for melanose control in 1920. 
Sprayed with 3-3-50 Bordeaux mixture plus one-half per cent 
oil. 
Date of examination. 
At intervals of four 
weeks with one 
application of 
sulphur. 
At intervals of two 
weeks with one 
application of 
sulphur. 
At intervals of four 
weeks with no 
spraying with 
sulphur. 
Not sprayed 
(check). 
Total 
number 
of rust 
mites. 
Average 
number 
per 
square 
inch. 
Total 
number 
of rust 
mites. 
Average 
number 
per 
square 
inch. 
Total 
number 
of mites. 
Average 
number 
per 
square 
inch. 
Total 
number 
of mites. 
Average 
number 
per 
square 
inch. 
June 25 
248 
704 

33 
94 


1,112 


148 

1,233 
1,138 
164 
152 
July 8 
1,072 
631 
143 
December 2 
84 
On July 8 there were as many mites on the sprayed trees as on the 
unsprayed. The fruit, however, from the part of the plat not sprayed 
with sulphur but having the 4-week applications of Bordeaux-oil 
emulsion was very much russeted. The last examination, made De- 
cember 2, showed that no mites were present on the sprayed plats. 
No doubt this was due to the heavy coating of Bordeaux mixture on 
the foliage. 
1921 TREATMENTS. 
Grove D, at Orlando, Fla., was divided into 38 plats and sprayed 
from one to five times for melanose control, beginning April 28 and 
on most plats ending June 9. Various spray materials were used, 
including a wide range of sulphur compounds as well as various 
strengths of Bordeaux-oil emulsion ; but single Bordeaux mixture was 
not used. Melanose was controlled very satisfactorily wherever Bor- 
deaux-oil emulsion was applied before infections occurred. 
Table 5. 
-Effect of spray applications on development of entomogenous fungi, the 
white fly, and the purple scale in 1921. 
Kind of sprays. 
Pustules per leaf. 
Brown 
fungus .» 
Red b and 
yellow c 
fungi. 
Scale 
fungus .d 
Number per leaf. 
White-fly 
pupae, e 
Adult 
female pur- 
■ ./ 
Sulphur sprays 
Copper sprays. . 
Unsprayed 
20 
3.3 
1.8 
6.6 
0.61 
.44 
1.32 
a Aegerita webberi Fawcett, on the citrus white fly (Dialeurodes citri). 
b Aschersonia aleyrodis Webber, on the citrus white fly. 
c Aschersonia flavo-citrina P. Henn, on the cloudy winged white fly, Dialeurodes citrifolii Morgan. 
d Sphaerostilbe coccophila Tul., on the purple scale. 
« Dialeurodes citri Ashmead. 
/ Lepidosaphes beckii Newman. 
The effects of the spraying on the entomogenous fungi as well as 
on the the white flies and scale insects were determined by examina- 
tions made on August 22 and from November 28, 1921, to January 5, 
1922. Since there was no distinctive difference in the results ob- 
tained in the examinations, they are combined in Table 5. There 
