8o 
FLORIDA STATE HORTICULTURAL SOCIETY. 
insect or fungoid and bacterial enemies. 
We may roughly divide insect pests into 
(I), those which are always with us, such 
as scale insects and the whitefly, and (2) 
those whose appearance in sufficient num¬ 
bers to be destructive is uncertain. Among 
such may be mentioned the several leaf- 
hoppers, destructive 'to corn, beans, etc., 
grasshoppers, chinch-bug, and others. 
The fact that these latter can generally be 
found only in small numbers, or practi¬ 
cally disappear altogether, except, during 
periodic and sporadic periods of increase, 
this results in a natural decrease of their 
enemies to a minimum. It being practi¬ 
cally almost impossible to cultivate a sup¬ 
ply of their insect enemies on artificial 
foods 6r other insects, and generally diffi¬ 
cult enough to artificially cultivate their 
fungoid or bacterial enemies, it follows 
that the enemies of these pests are gener¬ 
ally not at hand in sufficient abundance to 
meet the requirements when an outbreak 
of such a pest occurs. All this, together 
with the possibility of unfavorable weath¬ 
er conditions, in case the enemy supplied is 
a fungus, makes the proposition a difficult 
one. 
When considering the proposition of 
controlling the first (i) class by means of 
their natural enemies we have this great 
advantage, namely, that the insect is gen¬ 
erally with us in abundance at all times 
and hence also its enemies; and our work 
is simplified to this extent, that about all 
we have to do is to devise methods of 
spreading its enemies to' keep them abreast 
of the pest and to protect them by creating 
conditions favorable for their increase. 
If we desire to supplement their natural 
increase by cultivating themi in the lab¬ 
oratory, it will be mainly for the purpose 
of observing them at closer range and un¬ 
der peculiarly favorable conditions other¬ 
wise unobtainable. It is under the favor¬ 
able conditions accompanying this first 
(i) class of insects that we are laboring 
in our effort to control the whitefly and 
scale insects of Florida. 
