10 FARMERS’ BULLETIN 166. 
METHODS OF CONTROL. 
The imported cabbage worm is not difficult to control, and it should 
be borne in mind that most other “ worms” will be controlled by the 
same methods, and that other cabbage pests are more often present 
than not. 
ARSENICALS. 
Repeated experiments have shown that the best remedy is one of 
the arsenicals; and that arsenate of lead and Paris green are prefer- 
able to others in common use. If Paris green is used it may be 
applied either wet or dry, preferably, however, as a spray, at the rate» 
of 1 pound to 50 gallons of water. The plants should be free from 
insect attack when they are set out, and should be sprayed a few days 
later to make sure that the poison reaches the young caterpillars 
before they have burrowed far into the heads. Other applications 
should follow as inspection of plants shows that they are necessary. 
These applications of arsenicals can be made with absolute safety 
until the heads are nearly formed, and, for that matter, even later, 
as the poison disappears from plants almost completely within two 
to three weeks after application, and even earlier in event of repeated 
or heavy rainfall. After the removal of the outer leaves, in prepara- 
tion of the cabbages for market, and after other leaves have been 
picked off, as is done before the cabbages are cooked or cut up for 
salad, there is usually very little, if any, of the arsenic left. 
HARMLESSNESS OF ARSENICALS WHEN PROPERLY APPLIED. 
Chemical analysis has shown that cabbage which has been sprayed 
or dusted with an arsenical as prescribed, and prepared for cooking 
in the usual manner a week later, has not even a trace of the arsenic 
remaining. The use of arsenicals against cabbage worms is almost 
universal in the United States, although growers are sometimes loath 
to acknowledge the fact for fear of the loss of customers who are not 
fully acquainted with the harmlessness of the remedy. There are no 
authentic recorded instances known to the writer of poisoning from 
the consumption of cabbage treated with an arsenical. It has been 
proved that 28 cabbage heads, dusted in the ordinary way with Paris 
green, would have to be eaten by an adult human at one meal before 
poisonous effects could be produced. The experience of a Virginia 
market gardener who dusted his cabbage with Paris green and flour, 
omitting to inform his family of the fact, should be cited. A day or 
two later he ate heartily of this cabbage, as did others, and after- 
wards was questioned by his wife as to the peculiar powdery substance 
on the heads. Although poisoning was anticipated, no ill results 
followed. 
