120 PESTS OF GARDEN AND FIELD CROPS 
In the fall eggs, larve, and adults may be found in old cabbage 
stumps. 
The maggots may be Killed by pouring around each plant a half cup of 
carbolic acid emulsion. A pointed stick may be thrust diagonally 
beneath each plant and a teaspoonful of carbon bisulphide poured 
down the hole. 
The maggots may be prevented from gaining access to the roots by 
fitting a disk of tarred paper around the stem of each plant. The disks 
should be about four inches in di- 
ameter, slit to the center, and marked 
with short cross cuts at this point, so 
that they may be fitted closely and 
easily around the stem. When in 
place, the disks rest flat on the ground. 
Ahandy tool for cutting hexagonal disks 
in quantity is illustrated. After the 
first row of cuts has been made across 
a sheet of cardboard each additional 
cut will make one disk. 
It is of importance to clean up all 
old cabbage stumps in the fall. Deep 
plowing will reduce the number of the 
flies the succeeding year. Rotation of 
crops is desirable. Abundant fertil- 
ization will help cabbages to withstand 
attack. 
The Onion Maggot (Phorbia cepetorum 
Meade) 
Infestation by the onion maggot is 
similar to that of the related species 
working on the roots of cabbage and 
i radish. The eggs are laid by the adult 
Fic. $9.—Work of the Onion fly in the leaf sheaths, and the mag- 
Maggot. Original. gots work their way down into the 
