4 88 ECONOMIC ZOOLOGY AND ENTOMOLOGY 



peach-tree borer. The eggs may be laid on any part of the 

 plant. In the South there may be two generations each 

 year. As the borers feed in the vine they cannot be reached by 

 insecticides. A gummy exudation usually discloses the posi- 

 tion of the larvae, and it is sometimes worth while to slit the vine 

 open and kill the pest. The vines should be burned as soon 

 as the crop is gathered. Fall and winter plowing and crop 

 rotation will help to control such insects as these. 



The Onion-maggot (Pegomyia ceparum). The roots and 

 bulbs of onions are sometimes attacked by small white maggots 

 that in appearance resemble the cabbage-maggot. The 

 adults of the two species are closely related and can only be 

 distinguished by close examination. The cultural methods 

 suggested for controlling the cabbage-maggot are effective in 

 dealing with this insect also. 



The Tomato -worms or Tobacco-worms which are often 

 serious pests on tomato vines are described on page 499. 



