40 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



infested clover immediately after it is cut and exposing the roots 

 to the sun and wind, which will soon dry them out and thus destroy 

 the food of the larvae, which will soon perish. 



Trap Crops. Trap crops are those which are planted as a bait 

 or lure to attract the early insects so that they may be destroyed 

 upon them before the crop to be protected is available. Doubt- 

 less the reason that trap crops are not more frequently used by the 

 farmer is because their successful use requires more or less of a 

 knowledge of the life history and habits of the pest to be fought. 

 But that is easily acquired and will make the fight against them 

 more interesting and successful. 



South of Mason and Dixon's line the harlequin cabbage- 

 bug frequently becomes the most serious pest of cabbage and 

 related plants. When a cabbage patch has become well infested 

 it is an exceedingly difficult matter to prevent injury, for the adult 

 bugs cannot be killed by insecticides which will not injure the 

 plant. If, however, a crop of kale be planted the previous fall, 

 the bugs which hibernate over winter will attack it in the spring, 

 and may then be killed by spraying them with pure kerosene, and 

 the danger to the cabbage crop be thus largely averted. 



A few rows of wheat are often planted early in the fall as a trap 

 for the Hessian fly, and as soon as the eggs are deposited they are 

 plowed under deeply and the later planting thus at least partly 

 protected. 



One of the most successful examples of averting injury by a 

 trap crop is the use of corn to lure the cotton bollworm and thus 

 prevent its injury to cotton. Corn is the favorite food plant of 

 this pest, which prefers to deposit its eggs on the silk and tassels. 

 By planting a few strips of late-maturing corn through the cotton 

 field, they will come into silk about the time the brood of moths 

 which normally deposit their eggs on cotton are flying and they 

 will lay them on the corn in preference, which should then be cut 

 and fed to stock. In this way by planting strips composed of sev- 

 eral rows planted at successive dates, the cotton may be almost 

 entirely protected. Possibly a modification of this method may 

 be applied for the protection of tomatoes or tobacco, though these 



