120 



PESTS OF GARDEN AND FIELD CROPS 



In the fall eggs, larvse, and adults may be found in old cabbage 

 stumps. • 



The maggots may be killed by pouring around each plant a half cup of 

 carboUc 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. 

 A handy 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 wdll 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 

 radish. The eggs are laid by the adult 

 Fig. 89. — Work of the Onion % in the leaf sheaths, and the mag- 

 Maggot. Original. gots work their way down into the 



