118 REPORT UPON COTTON INSECTS. 



Respecting Mr. Affleck's statements, there is but little to be said except 

 in praise of the accuracy of his observations. Had there been in the 

 South many observers of insects as careful as he was, the mooted points 

 respecting the life history of the cotton-worin would have been cleared 

 up long ago. His observations are of peculiar interest to us, when we 

 remember that he was not a professional naturalist, but simply a very 

 industrious and observing planter, who did all he could to advance the 

 best methods of agriculture. 



Mr. Affleck observed that while this insect remained only eight or 

 nine days in the pupa state during the summer, as the season ad 

 vanced it underwent its transformations much more slowly, and lie 

 very naturally concluded that the species hibernated as a pupa. But 

 after trying experiments upon pupae, and observing the moths flying 

 during the winter, he changed his views, and published in his almanac 

 for 1851 his belief that the species hibernated as a moth. Although Mr. 

 Affleck does not state distinctly the reasons for his belief that the moths 

 "are not unfrequently brought on a gale of wind from the West Indies, 

 Mexico, or the coast of Guiana," a careful study of his paper leads us to- 

 infer that he believed that during warm winters the moths emerged 

 prematurely and were all destroyed by the cold ; and that following such 

 winters the worms were unusually late in making their appearance, their 

 presence being dependent upon an influx of moths from regions farther 

 south. It is an interesting fact, in this connection, that many planters 

 have a theory just the opposite of this. They believe that as the insect 

 was originally a tropical one it is unable to endure unusually severe 

 winters; and they state that the seasons following such winters are not 

 likely to be marked by extensive ravages of this pest. 



In Dr. Gorham's article we find abundant meterial, if it were reliable, 

 for the complete establishment of the theory of migrations. First, as to 

 the " periods of this insect." Although there are many instances of a 

 locality escaping severe ravages of this pest for many years, still we find 

 published accounts of its appearance in destructive numbers in some 

 portion of the cotton belt every year since 1825, and of numerous in- 

 stances prior to that date, though from insufficiency of records we can- 

 not state positively that it occurred every year from the time of its first 

 appearance in our country. Hence, even if it did entirely disappear from 

 some portions of the cotton belt, it is not necessary to suppose that those 

 sections have been restocked by immigrations from foreign countries, at 

 least since 1825. The principal argument, however, upon which Dr. 

 Gorham based his theory, was the supposition that A. argillacea never 

 remains more than ten days in either pupa or adult state, and conse- 

 quently could not survive the winter season. We have shown in Chap- 

 ter III, that the length of time required for this insect to complete its 

 transformations varies greatly; that it may remain a mouth in the pupa 

 state; and that it is known to remain several months in the adult state. 

 Dr. Gorham's illusions respecting those points furnish good evidence 



