FLORIDA STATE HORTICULTURAL SOCIETY. 
105 
quite thin, the lady bird forces its man¬ 
dibles through the covering and into the 
scale, then drags it out through the roof 
of its house, eating at times as many as 
three scale per minute. Cuba has a small 
steel blue lady bird that might be of use 
to us. 
While we always find many micro¬ 
scopic, but predacious appearing mites 
running around among scale, I have 
never been able to detect them in prey¬ 
ing upon the latter. 
Also, if hymenopterous flies attack the 
purple scale, I have never noticed it, but 
have seen them clean up a tree badly in¬ 
fested with wax scale. 
INSECTICIDES. 
Where man interferes with the bal¬ 
ance established by Nature, he is quite 
apt to bring about a series of reactions, 
often unlooked for by him, and this is 
especially true in spraying orange trees, 
where the insecticide used not only often 
directly injures the tree, but usually de¬ 
stroys the natural enemies of the scale, 
and the grower thus places himself under 
obligations to do much work that Nature 
would otherwise do for him; but upon 
the other hand, where the grower is suffi¬ 
ciently informed, he can keep his trees 
clean of scale and rust mites by spraying, 
and without injury to the trees, but at 
a cost justified only by a fair price for 
oranges. 
Of the most effective insecticides for 
scale, we would first place either resin 
compound or resin wash, but the former 
is apt to gum the pump: this can, how¬ 
ever, be remedied by adding, say five per 
cent, of kerosene to the compound in 
making and thoroughly incorporating 
the same. Both of these washes, if used 
two or three times during one season, 
will show bad results upon the trees, 
probably by gumming up the pores of the 
leaves and bark. 
Second comes kerosene emulsion, 
which is rather less effective upon scale 
than the resin washes, and is quite varia¬ 
ble in its effect upon the trees, depending 
upon whether the weather be clear or 
cloudy and also whether the trees are 
thrifty or not. 
During clear weather the oil evaporates 
quicker, and thus affects the tree less, 
and a thrifty tree will withstand much 
more kerosene than a hardened up one. 
Besides, kerosene emulsion has killed 
many large trees by being carelessly 
made, the oil separating and being 
sprayed upon the trees unnoticed by the 
workman. 
Third, and safest of all our scale spray¬ 
ing compounds, comes the various pot¬ 
ash fish oil soaps, often called whale oil 
soaps. At the strength advisable to use 
these soaps are not as effective as the 
above resin washes; however, its non-in¬ 
jury to the tree enables the grower to 
use it so repeatedly as to thoroughly 
clean a tree of all insect enemies, except¬ 
ing rust mites, which for some reason 
seem proof against the soaps, perhaps 
because of their diet of oil; this can be 
remedied, however, by adding some sul¬ 
phur and caustic potash compound to the 
soap. Many of these soaps are made 
with caustic soda, which makes a hard 
soap, while caustic potash makes a soft 
one, which is to be preferred to that made 
from caustic soda, for its fertilizing prop¬ 
erties, if for no other reason, but again 
it mixes with water more readily than a 
caustic soda soap. 
Personally, we have not sprayed for 
scale but one season during the last 
twelve years of our orange growing, and 
