CHAPTEE IV. 



THE THEORY OF MIGRATIONS OF THE MOTH. 



Although we have expressed our belief, in Chapter III that the cotton- 

 worm hibernates as a moth in certain portions of the United States, we 

 feel it important to give an account of the theory of migrations, which 

 has played so prominent a part in the discussion repecting this insect. 

 It should be stated that, although this theory is now held by but few 

 people, among the number are those who rank high as entomologists 

 and who have also had considerable experience in the study of this 

 particular species. 



In order to give those who have proposed this theory due credit, we 

 will state it in their own words. The earliest hint that we have found 

 of the possibility that the cotton- worm may be brought frequently to 

 this country from regions farther south, is contained in the following 

 extract from a letter by Mr. Thomas Affleck, published in the American 

 Agriculturist for November, 1846 (vol v., p. 342) : 



The pupa is black or dark brown and shining. From the moment it begins to spin 

 until it issues from the pupa a perfect moth is from eight to nine days of warm sea- 

 sonable weather, but if unusually cool it extends to a longer period, even to weeks ; 

 hence I am inclined to think that it is in the pupa state the insect is preserved over 

 winter. In fact, there is no doubt that many are thus saved the moths that are seen 

 occasionally on a warm winter's day, having been hatched prematurely by the unsea- 

 sonable warmth of the weather, and quickly perish from cold and waut of food. Bat 

 whether we at all times receive our supply from this source, or whether (which I think 

 is quite as probable) they are not unfrequently brought on a gale of wind from the 

 West Indies, Mexico, or the coast of Guiana, will be difficult to decide. My observa- 

 tions lead me to the conclusion that after a steady cold winter we have the caterpillar 

 early and in abundance ; and after a mild or warm one we have them, if at all, but 

 partially and late in the season. The pupa is frequently found during winter safely 

 sheltered under a scale of bark, between two evergreen leaves, under the splinter of 

 a fence-rail, or in a tuft of pine leaves. 



Early in the following year (1847) Dr. D. B. Gorham, having independ- 

 ently arrived at the conclusion that we have an influx of the cotton -worm 

 every year from more southern countries, published a paper on the sub- 

 ject in De Bow's Review (vol. iii, pp. 535-543). We quote those parts 

 of the paper referring to this theory : 



Let us now pass to the consideration of the cotton-fly, premising, however, before 

 entering into an examination of this destructive little moth, that my remarks are in- 

 tended less to enlighten others than to elicit information from some one who is better 

 able to inform.the public mind on this interesting subject. As for myself, I must con- 

 fess that my limited observations do not justify me in coming to any positive conclu- 

 sions, and have by no means satisfied my curiosity ; but my information, such as it is, 

 I give in the following pages, with the hope that however imperfect it may prove in 



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