INSECTS INJURIOUS TO SWEET CORN I99 



Rill-bug injury in general may be avoided by not planting 

 corn in land already liable to be infested, sucb as swampy 

 ground, river bottoms, or in soil in which rank grasses and 

 sedges are growing. Before planting, such ground should be 

 thoroughly broken up and grown to some crop which the 

 beetles will not injure. Bill-bugs so far as known injure only 

 corn, rice, timothy, nut-grass and other grasses, and occasionally 

 smaller grain. Cotton, tobacco, buckwheat, potatoes or other 

 garden vegetables, or other crops than those mentioned as 

 susceptible to bill-bug attack, will serve as alternates. 



Direct remedies are possible against bill-bugs whose larvae 

 also injure corn. One of these consists in plowing up and 

 burning infested stubble, when the larvae are present in such 

 numbers that the ruin of a crop is assured. This should be 

 done late in July or early in August for most localities, 

 before the insects have matured and issued from the stalks 

 as adults. Some species, e. g., the Southern corn bill-bug, pass 

 the winter as adults in the stubble and for these burning over 

 the fields as soon after harvest as possible is indicated. In the 

 case of the Northern bill-bug do not plant corn after timothy. 



The Common Stalk-borer {Papaipcma nitcla Gn.). — This in- 

 sect enjoys the distinctive designation of the stalk-borer, but 

 it has numerous other names of which are the heart-worm and 

 potato stalk-borer. Although a general feeder, it is quite as 

 commonly found attacking corn as other crops, hence may be 

 mentioned in connection with the two species that have just been 

 considered. 



The moth (fig. 127, a) is medium gray-brown or fawn color, 

 and marked as shown. The growing larva {h) is peculiar in 

 having the first three or four abdominal segments suffused in 

 such a manner as to give it the appearance of being diseased. 

 The mature larva measures about an inch and a half and has 

 more or less the appearance shown at c. The abdominal seg- 

 ment of the larva is shown at d, while at e is shown the female 



