FLORIDA STATE HORTICULTURAL SOCIETY. 
57 
we have had did a great deal towards, 
the destruction of the scale. 
Mr. Griffing—Last year we had a very 
wet, rainy winter and spring and early 
summer. This year we have had identi¬ 
cally the reverse, so I don’t see how the 
drv weather can be accountable for the 
disappearance of the scale. 
Mr. 'Hudson—I have noticed in setting 
out young trees, that the scale appears on 
the body of the tree within about ten 
months after it has been planted out. I 
have used a little coal oil and find that it 
works very well. The older trees can 
stand the scale better than the younger 
ones. I have also noticed that the scale 
takes more readily where there has been 
much vegetable matter in the way of 
beggar-weed, etc. 
Mr. Waite—Is there any injurious ef¬ 
fect to the orange trees by using sulphur¬ 
ous acid as a spray for foot rot? 
Prof. Rolfs—^There would be no in¬ 
jurious efTfects by using it in a diluted 
state. The dilution is about one to ten 
of sulphurous acid. The sulphurous acid 
is one of the first remedies recommended 
for foot rot, and you will find that it 
does no damage tO' the sound wood. Sul¬ 
phurous acid is what was recommended 
first, and by mistake some people have 
used sulphuric acid. This latter will cure 
the foot rot all right—so will a red hot 
iron. 
I would like to say in connection with 
the rust mite and the red spider, that in 
each of these cases I have found that 
diseases attacked thenii as well as higher 
insects. They do not exactly belong to 
the insects, but tO' the spider mites. They 
are attacked by diseases as well as higher 
life, but when you attempt to inoculate 
them with disease germs you will see that 
it is a very difficult thing. The practica- 
hility of the scheme falls down when you 
come to applying it. The difficulty is 
almost unsurmountable. Dry sulphur, 
or the sulphur and lime that Mr. Hamp¬ 
ton has recommened, is a perfect remedy 
for it. On my own trees I used this 
calcium sulphide and had it applied merely 
to the fruit. I gave the colored man 
special instructions to apply it to the fruit 
only. By use of a hand lens, one can 
tell when the mites are migrating tO' the 
fruit and causing it to turn them to a 
rusty or golden rust. If they are present 
in sufficient numbers tO' cause it to turn 
to a golden rust, the spray should be ap¬ 
plied. 
Member—How can you spray the fruit 
without spraying the leaves at the same 
time? 
Prof. Rolfs—The citrus fruits are 
nearly always on the end of the branch, 
and are away from the leaves. The fruit 
that is inside in the dark is not apt to 
be attacked by the rust mite. 
