THE BOLL WORM FOOD-PLANTS. 3GI 



Last fall (1881), in the vicinity of Canton, 111., Professor Barnard ob- 

 served that much damage was done to late corn, over two-thirds of the 

 ears harvested liaving contained one or more worms. Live worms were 

 found in the ears up to the time of husking, in the latter i)art of Octo- 

 ber, feeding upon the hard kernels. The ears thus damaged exhibited 

 on husking many shallow grooves through the tops of the kernels, which 

 seemed, indeed, the favorite mode of work of the worms; but occasion- 

 ally a single kernel would be eaten down to the cob. There, as else- 

 where, mildew had served to greatly increase the damage done by the 

 worm. 



In the Southern States there are always three broods of the worm 

 upon corn, the later broods preferring the tender cotton bolls to the 

 tough corn. The moths in early spring lay^heir eggs on the leaves of 

 the corn, and the newly-hatched larvae begin feeding at once on the 

 spot of their birth. By these young larvae many irregular holes are 

 eaten through the tender leaves, giving them, as has been well said, the 

 appearance of having been riddled by a charge of small shot. In this 

 manner they feed for sometime, gradually working their way downward 

 into the sheath of the leaf, and finally reaching the closely- rolled ter- 

 minal bud, into which they bore and remain feeding until they attain 

 their full growth, when they gnaw directly outwards, and, crawling into 

 the ground, transform to pupae. 



The eggs of the second brood are laid upon the leaves and upon the 

 sheaths of the tassels about the 1st of June. The worms feed, as be- 

 fore, upon the leaves at first, upon the tassels, and, later, as they ap- 

 proach full growth, they are to be found feeding upon the kernels, silk, 

 and cob of the forming ears. 



The third brood, commencing shortly after the 1st of July, may be 

 compared in its destructiveness to the second brood at the North. It is 

 very numerous, and is the last brood which injures corn to any extent. 

 The eggs are laid upon the end of the husk or amongst the silk, and 

 the worms work in the manner previously described, occasionally pierc- 

 ing the husk and migrating from one ear to another, although the ten- 

 dency to do this is much less w^hen the ears are tender than after the 

 grains have begun to harden. The worms of this brood pupate in the 

 usual way, and those of the next betake themselves almost exclusively 

 to cotton. Occasionally a worm is found working in the ears of hardened 

 corn in close proximity to a cotton-field, but it is a comparatively rare 

 occurrence. 



Much of the history of the Boll Worm ui>on cotton is inseparably con- 

 nected with its life upon corn, so that we shall have occasion hereafter 

 to again refer to its relations to the latter crop. 



Tomato.— Perhaps next in importance to the damage done to cotton 

 and corn comes that done to the tomato crop. In 1867 the Boll Worm 

 played havoc with the tomatoes of Southern Illinois, ^r-ating into the 

 green fruit and causing it to lot. (See Amaican Entomologist, I, 212). 



