l8 INSECTS INJURIOUS TO VEGETABLES 



Late planting is practiced against numerous insects with ex- 

 cellent success, the object being to have the crop appear after 

 the disappearance or dispersion of the insect whose ravages are 

 feared. It is, in fact, a standard remedy against some insects. 



THE MAINTENANCE OF VIGOROUS GROWTH 



If plants be weakened through atmospheric or other cause or 

 through a combination of unfavorable conditions they are as a 

 general rule more subject to injury by insects, but there are 

 many crop plants, as for example certain varieties of wheat, that 

 the ranker the growth the more they are subject to infestation 

 by such insects as the Hessian fly. 



Some have claimed that weak plants only are subject to injury, 

 and that plants might be grown by artificial methods for the 

 production of such great vigor that insects would not seriously 

 damage them. Although this might be possible with a limited 

 number of plants, we can not now procure all of the most favor- 

 able conditions. As an instance, we have only to cite the re- 

 ported successful use of kainit and nitrate of soda as a remedy 

 for wireworms and some other insects in New Jersey, and their 

 failure when applied in other states. Possibly soil and atmos- 

 pheric conditions have in some instances had some bearing upon 

 these failures. Most failures, however, are due to wrong methods. 



BURNING OVER FIELDS AND WASTE LANDS 

 A farm practice in favor in many regions against cereal-feed- 

 ing insects consists in burning over fields after harvest or be- 

 fore plowing. It afifects particularly such insects as hibernate 

 on or just below the ground. Among well-known pests that 

 can be reached by this method are cutworms, many of which live 

 all winter long above the earth's surface partially grown, also 

 webworms, grasshoppers, aphides and plant-bugs, and some 

 forms of beetles and other insects which hibernate in the adult 

 stage at or near the surface. 



