70 
FLORIDA STATE HORTICULTURAL SOCIETY. 
of plants can be mentioned the several 
blights of vegetables and fruit trees and 
some root diseases, all caused by bacteria 
or fungi. In fact, nearly all plant dis¬ 
eases not caused by insects or other ani¬ 
mals belong to this class. 
A printed list would be a long one. 
But, were plants and animals to vote on 
the greatest pest of all living things, no 
doubt mian himself would receive a un¬ 
animous vote as the most wanton des¬ 
troyer. And the object of all this so- 
called fighting of pests, in sum and sub¬ 
stance, is but to make for man, that larger 
parasite, a little easier living, a little purer 
atmosphere to breathe, and perhaps add a 
span or two, to his human existence. 
Briefly stated, the present relative signifi¬ 
cance and abundance ot each animal and 
plant group is the result of a struggle 
to make a living. In this struggle differ¬ 
ent groups began to prey upon other 
groups and the whole kingdom of living 
things (plants and animals) has become 
in a manner somewhat delicately balanced 
in regard to relative numbers. 
NATURE BALANCED AND UNBALANCED. 
But nature occasionally gets a little out 
of balance, so to speak. Either some plant 
or animal group gets out of its place and 
begins to feed upon some other plant or 
animal group not normally its food, or 
it increases abnormally either in propor¬ 
tion to its food or out of proportion with 
its natural enemies. In either case, it be¬ 
comes a pest proper, in the sense that we 
ordinarily use the term. Our so-called 
fighting of pests consists also' in nothing 
more than in an endeavor tO' restore the 
equilibrium! in nature or in overbalancing 
the same in favor of the crop that we wish 
to harvest. To accomplish this we may 
use artificial means for combating the 
pest, such as spraying, poisoning, fumi¬ 
gating, etc., or we may artificially spread, 
or propagate and spread, some known 
enemy of the pest that we desire to con¬ 
trol, or in other words, propagate a pest 
of the pest. 
As already stated, nature is generally 
quite balanced in the relative proportion of 
each kind of living thing. It is only when 
any one of these finds a great abundance 
of food, or some calamity keeps its ene¬ 
mies in check, or it is transplanted into 
some other country or district where its 
enemies have not followed, that it can in¬ 
crease abnormally. I refer, of course in 
particular, to plants and animals ordinari¬ 
ly known as pests. Thus if we plant an or- 
ange gTove, we bring into existence an 
enormous amqunt of food for orange in¬ 
sects, with the result that the latter may 
increase enormously, much more rapidly, 
for a time at least, than their enemies. If 
left alone, the natural enemies of some of 
these would (in fact have done so), very 
likely at sometime strike a balance and 
control, if they did not exterminate, the 
same. 
NATURAL ENEMIES OF SCALE INSECTS IN 
FLORIDA. 
However, we do not ordinarily care to 
wait for nature to strike this balance, as 
it might necessitate replanting our grove 
for a life-time, and we either try to keep 
the insects off by some artificial means, or 
we try to discover their enemies and un¬ 
dertake to propagate them artificially, or 
in some manner encourage their increase. 
In the case of several of the scale insects 
of trees, in Florida, the fungus parasites 
of these have become very efficient when¬ 
ever the same were not destroyed by ex¬ 
tensive spraying, or whenever the grower 
