110 . EEPORT UPON COTTON INSECTS. 



the main, yet that some mite of information may be gleaned from it. It is impossible 

 to think for a moment that this species of moth has escaped the observation of ento- 

 mologists, for the plant upon which it feeds to the absolute exclusion of all others 

 (being the great staple production of many countries) must have brought it into notice 

 at various times and at various places. From its univorous nature (to coin a word) it 

 must have been coeval with and inseparable from the existence of the cotton plant. 

 My principal motive for broaching this subject is on account of the frequent remark 

 made and fears entertained that the army- worm would become an annual plague. But 

 seine I have investigated their nature, I have come to the conclusion that these fears 

 are groundless, and that the cotton-fly can never become naturalized in our climate. 



The first irruption, as I am informed by an old planter, that this insect made on 

 the cotton fields of Louisiana was about the year 1820, when its progress was marked 

 with the same utter destruction of the cotton crop as in the subsequent years of 

 their appearance. It then disappeared until 1840, a period of twenty years. There is 

 something singular and unaccountable in the periods of this insect, something vastly 

 different from the periodicities of others which we find with us, for they appear to be 

 governed by some fixed laws ; the most of them are annual, very few biennial. Now, 

 the grasshopper, house-fly, and mosquito may be looked for at the return of summer 

 with as much confidence and certainty as we look for the revolutions of the seasons. 

 The Cicada, septendecem never fails to make his appearance once in seventeen years. 

 But who can tell whether the cotton-fly will appear next year or fifty years hence T 

 No scourge, whether under the form of a devouring insect or that of a malignant dis- 

 ease, ever became annual in one particular place. Look at the lociist of Egypt ; sup- 

 pose that voracious insect to become annual, the prolific valley of the Nile, once the 

 granary of Asia and Europe, would become a howling desert. Look at the plague 

 that devastates sometimes Smyrna and Constantinople ; did the cause of that distem- 

 per act with the like intensity at each return of the season, those flourishing cities 

 would long since have been numbered with Thebes and Memphis. Let the cholera 

 or yellow-fever prevail in New Orleans every year as it has at times, and that great 

 emporium of the Southwest would become a puny village. Is there not an invisible 

 hand that sways the destinies of the world: a hand that stays the devastations of 

 plague, pestilence, and famine ? The cotton-fly belongs to that numerous class of in- 

 sects known to naturalists under the term of phalena or moth tribe. The following 

 are its specific characters, without the technicalities made use of by the naturalist, 

 so far as they could well be avoided. * 



During the present year, the time that my observations commenced for the first 

 time, the cotton-fly again made its appearance in the latter part of August, at first 

 making but little progress, but about the middle of September their numbers increased 

 so prodigiously that in many instances they would eat over a field of several hundred 

 acres in four or eight days. The number of eggs deposited by the female is uncertain ; 

 they are smaller than a mustard seed, and always deposited on the under surface of 

 the leaf during the night ; in a few days their eggs hatch. The worm, at first a mi- 

 nute living point, falls immediately to work to devour the leaf. Its growth is rapid, 

 for its labors cease not night or day until it arrives at maturity ; it then winds itself 

 up into a leaf by means of a web resembling a cobiceb, casts its skin, and changes into 

 a chrysalis, in which state it remains ten days, then it bursts the thin walls of the 

 chrysalis and comes forth a perfect insect. In turn, it begins the work of reproduc- 

 tion, deposits its eggs,' and in ten more days it dies. 



Thus in every ten days there is an additional generation, and they go on increasing 

 ad infmitum. As soon as the leaves were consumed in a field this great army took up 

 its march some in search of comfortable quarters where they might repose from 

 their labors, others on a foraging expedition replenish the means of their subsist- 

 ence. They first took shelter in the first leaf they met with, but generally they 

 proceeded as far as the fence, a barrier beyond which they never traveled, where they 

 found a plentiful supply of leaves in which they enveloped themselves. The second 



