132 INSECTS INJURIOUS TO VEGETABLES 



gots eroding the outer surface and boring into the interior of 

 the roots, devouring the tender rootlets and frequently pene- 

 trating into the lower portion of the stalk. This insect, known 

 also as radish maggot, is an imported pest. It does serious 

 injury throughout the northern tier of States and Canada, at- 

 tacking all forms of crucifers. It is the cause of more or less 

 loss to these crops each year. Since 1902 it has not only been 

 exceedingly destructive, but has increased in injuriousness from 

 year to year. Frequently entire crops over considerable areas 

 are completely destroyed. Two or three generations of this 

 maggot are indicated where it has been observed. 



The remedies prescribed for the seed-corn maggot are ap- 

 plicable. In addition there are certain preventive and other 

 measures for its destruction that have been found successful, 

 their use being justified by the great value of cabbage plants. 



Carbolic-acid emulsion, prepared as prescribed on page 37, 

 and diluted about 35 times, is applicable when this maggot oc- 

 curs on radish. 



Hand-picking, although laborious, has the merit of effective- 

 ness, and is useful on cabbage, although not practicable on 

 radish and similar crops. It consists in pulling up the young 

 plants, examining the roots for eggs and maggots, and either 

 destroying the eggs and maggots by crushing with the hand or 

 by washing the roots in a strong solution of soap and then 

 replanting. In most ca.ses the plants show no ill effects from 

 this treatment after two or three weeks have elapsed. 



Methods of cultivation. — Comparatively little can be expected 

 from various farming methods which are safeguards against 

 other insects. Keeping the soil well hilled around the cabbage 

 plants develops more roots, thus affording more food for the 

 maggots and leaving enough roots to strengthen the plant itself. 

 Crop rotation should be followed with any plants other than 



