GENERAL CROP PESTS 83 



ctablcs subject to attack can then be planted with much less 

 danger of serious infestation. It is difficult with our present 

 knowledge to name an absolutely immune crop. 



Poisoned baits. — An efficacious remedy is found in poisoned 

 baits. One of these consists in sowing corn, soaked in water, 

 containing arsenic or strychnine, over the field about ten days 

 before the crop is planted and then harrowing it in. The larvae 

 that attack the poisoned kernels will be destroyed. For luring 

 beetles, as well as larv?e, baits of sliced potatoes or other veg- 

 etables, or wads of succulent vegetation, such as clover, or pig- 

 weed, or sweetened corn-meal dough, are useful. These are 

 poisoned in the same manner as the corn and placed about the 

 fields under boards early in the season. These traps should be 

 renewed as often as possible. Experiments have shown the 

 futility of starvation of wireworms by clean fallowing. 



Although these remedies are not infallible against wire- 

 worms, they are of value in certain sorts of soils against some 

 species, and they serve in a manner to destroy white grubs and 

 cutworms which are also apt to be present. 



APHIDES, PLANT-BUGS AND RELATED INSECTS 



Nearly all forms of plants are attacked by sucking insects, 

 the aphides, plant-bugs, leafhoppers and numerous related 

 forms. The best known are the aphides or plant-lice, many 

 of which do injury to vegetable crops. Among other insects 

 which obtain nourishment by suction are several species of 

 true bugs of the family Capsidae, generally termed plant-bugs, 

 although some forms are also known as leaf-bugs, chinch bugs, 

 and other names indicative of their habits or appearance. The 

 commonest and most injurious of these insects to vegetables are 

 two forms of false chinch bugs, the tarnished plant-bug and 

 garden flea-hopper. The thrips also obtain their food by suc- 

 tion, and for convenience may be included in the same category, 

 although they are not closely related to them structurally. 



