Modern Warfare on Garden Pests 
DESCRIPTION AND CHARACTERISTICS OF THE ENEMY IiN DETAIL—WHEN AND 
WHERE TO EXPECT ATTACK—TACTICS AND AMMUNITION FOR DEFENSE 
T 
BY F. F. Rockwe l l. 
Photographs by Profs. Lowe and Britton and others 
m 
m 
A plum twig 
fested with 
Jose scale 
San 
T HERE is one section of modern war¬ 
fare in which no peace conferences 
are to be held; in which there are no ad¬ 
vocates of disarmament; in which the 
fighting must be without quarters and to 
the death — the war on plant enemies. 
And it must be a guerilla warfare — each 
planter fighting his own skirmishes by 
himself. It may be that our national and 
state governments will be able some day 
to take suitable and adequate steps toward 
the extermination of the several insects 
and disease pests that annually cause the 
loss of millions of dollars worth of crops. 
But until that happy day, each gardener 
must fight for himself, and in order to be 
successful, he must take advantage of 
every new engine of destruction or means 
of protection, of every more effective am¬ 
munition that invention and science places 
at his disposal, and fight it out with vigor and persistency. 
Nor is this all. In order to utilize these agencies in the most 
effectual ways, he must make himself master of the strategies of 
the situation; he must analyze the conditions and comprehend the 
individual factors in the campaign he will have to carry out. Only 
by so doing will he be able to apply the proper method of fighting 
to the particular battle to be fought. 
I use the term “method of fighting” rather than the more usual 
one, “remedies,” because both by experience and study I am con¬ 
vinced that so long as the commercial fields of horticulture remain 
in the present absolutely unorganized condition, and so long as the 
gardener, big or little, who is neglectful, and thus 
becomes rather a stockman than a gardener, breed¬ 
ing all kinds oi plant pests — just so long as this is 
permitted we can achieve no remedy worth the 
name. When speaking of a remedy in this con¬ 
nection, we very frequently are putting the cart 
before the horse, and refer to some means of pre¬ 
vention. Prevention is not only the best, but often 
the only, cure. 
The whole problem of plant enemies and meth¬ 
ods of combatting them is at present in a some¬ 
what complicated state. It has not received the at¬ 
tention from scientific investigators which other 
branches of horticulture have. Many experiments 
and discoveries have been made, but we have 
reached not nearly so definite a line of action as 
we have, for instance, in enriching the soil. 
Before taking up the individual insects and 
diseases, it will repay the gardener to try to fix in 
his mind the several classes of these, in order that 
he may make himself familiar with a few general 
principles, rather than get lost in a tangle of detail. 
To make the matter plain, then, the following 
analysis and list will enable the reader to get a gen¬ 
eral comprehension of the whole matter. 
Plant enemies we have to fight may be 
put under four heads, as follows: — 
Insects ^ at i n .g and chewin g 
(Bucking 
DiseaseJ FtUlgOUS ° r § erm 
From the above it is seen that plant ene¬ 
mies are of two kinds — insects and di¬ 
seases. Of the former there are two sorts; 
( i ) those which chew or eat the leaves, 
stems or fruit, and are usually hard- 
shelled; and (2) those which suck the 
plant juices and are usually soft-bodied. 
It will at once be seen that the first class 
can best be reached by internal poisons, 
and the latter by external ones, as it has 
never been found possible to get effective 
poisons into the sap or juices of the plant. 
Of the diseases also there are two sorts, 
fungous or germ diseases, resulting directly or indirectly from the 
attack of parasitical fungus or germ; and constitutional diseases, 
which attack the organism of the plant as a whole. Of these lat¬ 
ter very little is known. Sometimes they may be caused by im¬ 
perfect nutrition, or again by an oversupply; often there is no ap¬ 
parent cause. Failing to discover a fungous or bacterial origin, 
and finding the disease attacking the whole plant, experts place 
the ailment in this general class and seek different remedies. 
It thus becomes evident that the remedy to be used must de¬ 
pend upon the enemy to be fought. We can therefore reduce the 
matter to a simple classification, as follows: — 
4 twig bearing the 
egg mass of the 
tent-caterpillar 
Insects 
Diseases 
Plant Enemies 
Class 
j Eating... A 
(Sucking. B 
^Parasitical . C 
(Constitutional . D 
Remedies 
Number: 
(Covered Boxes. 1 
Mechanical .( Collars. 2 
(Cards. 3 
Hand-picking . 4 
Destructive 
A 
Kerosene emulsion 
Whale-oil soap . 
Miscible oils. 
Tobacco dust . 
Carbolic acid emulsion 
Corrosive sublimate .. 
Bordeaux mixture . . . 
5 
6 
7 
8 
9 
10 
11 
A powder gun that dis¬ 
tributes a fine cloud of 
the insecticide 
(Paris green . 12 
Poisonous .(Arsenate of lead. 13 
(Hellebore . 14. 
(424) 
