300 EEPORT UPON COTTON INSECTS. 



not nearly so marked as in the latter. This method of walking, the worm 

 loses with its first or second molt. There is nothing remarkably char- 

 acteristic about these young larvae. They seem to be somewhat thicker 

 in proportion to their lengths than do the young cotton- worms, and they 

 have not so delicate and transparent an appearance. 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 depos- 

 ited 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 flower-bud. It was always interesting to 

 watch this seemingly aimless search, the young worm crawling first down 

 the leaf stem and then back, then dropping a few inches by a silken 

 thread, and then painfully working its way back again until at last it 

 found its boll or bud, or fell to the ground, where it was destroyed by 

 ants. 



Mr. Trelease was instructed to report upon the point of the eating of 

 the leaves by the young larvae, and the following is the report of his ob- 

 servations : 



Very soon after its exclusion, the young larva begins to feed upon the substance of 

 the leaf or bract, or other organ on which it finds itself; and when this chances to be 

 a leaf or bract, it leaves the epidermis on the other side for some time. Daring the 

 first half day or day of its existence it feeds in this way, forming small, irregular, 

 transparent spots in the blade of the leaf or in the bract, after which it pierces a 

 hole usually more rounded than that first formed by Aletia through the organ. 

 The age at which this is done appears, from my observations, to be earlier than 

 that at which the caterpillar pierces the leaf; but I find that it differs greatly with 

 different individuals, some piercing the leaf when less than ten hours old, some not 

 until they are about two days old. After this, if it does not find itself close to a 

 flower-bud, immature fruit, or some other object suitable for its food, the larva moves 

 about in search of this food ; finding which, it shortly goes to eating. Whatever may 

 be its food, this worm, according to my observations, always forms regular, round 

 openings in its exterior for its own entrance or exit ; and these vary in size with the 

 size of the larva, being just largo enough to allow the animal's body to pass with 

 ease. Another peculiarity of this larva is its wandering character, especially earlier 

 in the season when feeding on the flower-buds or forms of cotton ; for these, being 

 small, the contents of each is soon eaten by the worm, which necessarily moves on 

 in search of more food. 



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

 shorter space of time upon the part of the plant on which they are 

 born, but migrate sooner or later to flower-bud or boll. That the worm 

 may occasionally attain full growth, having fed upon the leaves alone, is 

 shown by the fact that Mr. Trelease, on May 30, found a partly grown 

 boll- worm feeding upon the leaves of cotton. At this time, the forms 

 were very few and very small. Comparatively early in the season, 

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



