INSECTS INJURIOUS 10 C.aBi3AGE AND OTHER CROPS I33 



crucifers or onions. With these latter it is inadvisable, as the 

 same atmospheric or other conditions which induce injury by 

 the cabbage maggot seem to operate in increasing the numbers 

 of the onion pest, which has a similar distribution. Fall plowing 

 is advisable and cabbage stumps should be removed and de- 

 stroyed, especially early in the season. 



Bisnlphid of carbon treatment.— In case tarred paper cards, 

 which will next be described, or other preventive methods are 

 not employed, bisulphid of carbon may be used. It should be 



Fig 84.— Bisulphid of carbon injector 

 in use 



Fig. 85.— Tarred paper card in 

 outline. One-half size. (After 

 Goff.) 



applied below the root system with a special injector or syringe,^ 

 taking care that the application is not made directly to the 

 plants, as it is likely to kill them. A hole is made a little 

 distance (3 or 4 inches) from the plant, and the injector in- 

 serted at an angle, as shown in figure 84. After injecting the 

 liquid the instrument should be withdrawn and the hole closed 

 by packing with the foot. From a teaspoonful to a tablespoon- 

 ful to each young plant, and a single application, is generally 

 sufficient. 



Tarred paper cards. — The use of disks or pads of tarred paper 



1 The McGowen injector, no longer for sale, has proved very successful. 



