FLORIDA STATE HORTICULTURAL SOCIETY. 
69 
Control of the White Fly by Natural Means. 
Df. E. W. Bcfgfcf. 
Mr. Presidentj Ladies and Gentlemen: 
A study and discussion of the different 
phases of this subject are exceedingly in¬ 
teresting and important whether consid¬ 
ered fromi a purely practical or from a 
purely scientific standpoint. When con¬ 
sidered from a purely practical standpoint 
it involves mainly the knowledge neces- 
sai*y for successful insect control. This, 
however, includes a knowledge of the life 
history, habits, and conditions of exist¬ 
ence of the insect pests to be controlled, 
of the fungus or insect parasites or other 
enemies that feed upon the pest, and the 
plants or animals that we desire to protect 
or rid of their injurious insects or other 
pests. And last but not least, a knowl¬ 
edge of the methods for propagating and 
distributing the natural enemies of the 
insect pest that we desire to control is 
absolutely necessary. Thus, to take the 
ease of the citrus whitefly as an illustra¬ 
tion, I find that I cannot arrive at a 
rational understanding of this “whitefly 
problem” without a comprehensive under¬ 
standing of the life history, habits and 
conditions of existence of the whitefly, of 
its fungus enemies and of the citrus tree 
itself. The methods for distributing, or 
propagating and distributing, the fungi 
must be solved in reference to the case at 
liand, guided, of course, by previous ex- 
]:)erience and the established principles of 
the subject. 
When considered from a purely scien¬ 
tific point of viezv this subject involves 
phases of the mutual dependence and re¬ 
lationship of living things as a whole. 
Aside from the many interesting facts of 
this relationship the question arises, how 
came this relationship about?—^^this de¬ 
struction of one kind of living thing by 
another kind. 
The truth of the matter is that nearly 
all animals are a “pest” in so far as some 
other animals or plants are concerned. 
Animals that live on decaying animal or 
vegetable matter are the only exceptions to 
this" among animals. Plants are thus 
about the only living things that live with¬ 
out breaking the commandment. Thou 
shall not kilf if you will allow me to 
temporarily extend this mandate to all 
living things. But even among higher 
plants we have those that kill other'plants 
and animals or at least live upon their 
substance. Thus the dodder in part lives 
upon and finally kills other plants; the In¬ 
dian pipe, beech drops and the green mis¬ 
tletoe feed Upon the sap of other plants. 
A few of the higher plants are also carni¬ 
vorous, feeding in part at least upon in¬ 
sects and the like, which they capture. 
Thus the drosera, or sundew, the Venus 
flytrap, the pitcher plant and bladderwort 
belong to this group. But the chief des¬ 
troyers in the plant kingdom, are the bac¬ 
teria and fungi which attack both living 
plants and animals as well as dead ones, 
and many of these are to be feared as a 
scourge, only too frequently leaving com¬ 
plete desolation in their path. To this 
class belong the cholera germ, consump¬ 
tion, typhoid, diphtheria and others, of 
which there are varieties attacking ani¬ 
mals as well as man. Among such pests 
