33 G EEPORT OF THE COMMISSIONER OF AGRICULTURE. 



lucre. Shoiikl if. be laid upon tlic leaf, as is usually tbe case, it may be 

 three days before the worm reaches the boll. Should it be laid u])on the 

 iuvolucre, the young worm bores into the boll at an earlier date. As a 

 rule, we may safely say that whei'e the egg is laid upon the involucre 

 the worm pierces through within twenty-four hours after hatching. 



The newly -hatched boll-Avorm walks like a geometrid larva or looper, 

 "a measuring worm," as it is often called. This is easily explained "by 

 the fact that, while in the full-grown worm the abdominal legs or pi'o- 

 legs are all nearly equal in length, in the newly-hatched worm the second 

 pair is slightly shorter than the third, and tlie tirst pair is shorter and 

 slenderer than the second, a state of things approaching that in the full- 

 grown cotton-worm, though the difference in size in the former case is 

 not nearly so marked as in the latter. This method of walking is lost 

 with the first or second molt. There is nothing remarkably character- 

 istic about these young larvae. They seem to be somewhat thicker in 

 proportion to their length than the young cotton-worms, and they have 

 not so delicate and transparent an api)earance. Their heads are black, 

 and their bodies seem already to have begun to vary in color. The body 

 above is furnished with sparse, stiff hairs, each arising from a tubercle. 

 I have often watched the newly-hatched boll-worms while in the cotton 

 fields. When hatched from an egg which had been deposited upon a 

 leaf, they invariably made their first meal on the substance of the leaf, 

 and then wandered about for a longer or shorter space of time, evidently 

 seeking a boll or fiower-bud. It was always interesting to watch tliis 

 seemingly aimless search, the young worm crawling first down the leaf 

 stem and then back, then dropping a few inches l)y a silken thread, and 

 then painfully working its way back again, until at last it found the 

 object of its search, or fell to the ground, where it was destroyed hy 

 ants. 



We may safely say, then, that the young larvae feed for a longer or 

 shorter space of time upon the part of the plajit on which they are born, 

 but usually migrate sooner or later to flower-bud or l)oll. That the worm 

 may occasionally attain fall growth, having fed upon the leaves alone, 

 is suggested by the fact that Mr. Trelease, on IMay oO, found a partly 

 grown boll-worm feeding upon tlie leaves of cotton. At this time the 

 forms were very few and very small. Comparatively early in the sea- 

 son, when feeding upon buds or small bolls, a single worm often does a 

 great amount of damage, i»roceeding from bud to bud or from boll to 

 boll. 



The destruction of the essentia 1 i)arts of the flower before the boll 

 pro])er is formed, is sometimes as great a source of loss as the destruc- 

 tion of the maturing bolls. 



It is quite a common sight to see large worms in the flower, as also 

 the younger individuals, the latter, however, usually having jDenetrated 

 the bud and forced the premature blossom. 



As the boll-worms increase in size, a most wondeiful diversity of color 

 and marking beconuis apparent. In color, diflerent individuals will vary 

 from a brilliant green to a deep pink or a dark brown, exhibiting almost 

 every conceival)le intermediate stage, and from an immaculate, unstriped 

 specimen to one Avith regular spots and many stripes. The green worms 

 are more common than tliose of any other color; but thOvSe of varying 

 shades of pink or brown are so abundant as to make it impossible to fix 

 upon a ty])e. Ji^arly in the season (as will be liereafter shown) the pre- 

 vailing color is green. A coiiunon variety is light green in color, liuu- 

 ning from the first ring back of the head to tlie posteiior end of the 

 body on each side is a broad whitish line; just above is a broad dusky 



