INSECTS INJURIOUS TO SWEET CORN I93 



istic, and usually show just below the surface. This is ac- 

 complished by more or less withering of the plant, which is 

 frequently killed outright by the destruction of the central 

 tuft of growing leaves. Frequently plants are destroyed al- 

 most as soon as sprouted. Should the plants survive ordinary 

 attack they are apt to fail to produce mature ears. If plants 

 which arc suspected of harboring this species are pulled up, the 

 root-worms can be dislodged, and it is not difficult to distinguish 

 them from other forms of insects found in the same locations, 

 with the exception of the western corn root-worm, which, 

 however, seldom occurs in the same regions. 



The beetle is one of our earliest as well as latest species. 

 Indications are that at least two and perhaps three generations 

 are produced annually in the District of Columbia, and prob- 

 ably four in the insect's more southern range. Eggs are laid 

 at the base of the insect's food plant and have been observed 

 by the writer to hatch in six and seven days in cool May 

 weather. 



Remedies. — We cannot reach the insect, to any extent, by 

 means of poisons and their use on growing corn is impractica- 

 ble. Therefore, we must have recourse to farm methods. 

 Injury to corn is greatest when seed is planted in bottom lands, 

 and if planting is necessary in such locations it should be done 

 late, in the Gulf region by the first of May, or attack may be 

 so distributed that damage will be inconsequential, by dropping 

 about ten grains of seed-corn in each hill. Of greater import- 

 ance, however, is judicious crop rotation. Numbers of crops 

 are not injured by the Southern corn root-worm, and can be 

 used as alternates. Of these are cotton, buckwheat, smaller 

 grains, and vegetables other than beans and cucurbits. In 

 the occurrence of the beetles on cucurbits remedies advised 

 against the striped cucumber beetle should be used. (See 

 page 158.) On beans a spray of arsenate of lead should be 

 employed. 



