116 REPORT UPON COTTON INSECTS. 



"become apparent that Prof. C. V. Riley lias regarded the same subject from an erro- 

 neous stand-point, having considered the cotton-worm as belonging to our fauna, and 

 accordingly misunderstood its economy as displayed with us and far from its natural 

 abode. And here, while I am obliged to differ on a scientific question with Professor 

 Riley, I bear willing testimony to the great good achieved by the publication of the 

 Missouri Reports. 



The Aletia argillacea, or cotton-worm, is an insect belonging to the Noctuse, a group 

 of nocturnal moths. It is one of a number of intertropical or Southern forms, some- 

 what nearly allied to our more thickly-scaled and Northern genus Plusia. The cater- 

 pillar is a " half-looper," to use a common term, and the chrysalis is held within an 

 exceedingly loose web on the plant, the few threads usually binding over the edge of 

 the leaf, and of themselves furnishing no adequate protection to the pupa. (I here 

 exhibit to the association specimens of the larva, pupa, and moth of Aletia.) Techni- 

 cal descriptions of the different stages are already extant, and so may be passed over 

 here. The more immediate question for our solution is the consecutive history of the 

 insect, so that we may be prepared to offer suggestions to the agriculturists for its- 

 destruction. 



The region over which, during five seasons, I have observed the cotton-worm, em- 

 braces the central portion of the cotton belt in the States of Georgia and Alabama, 

 and in particular the counties of Marengo and Greene, lying along the Tombigbee and 

 Black Warrior Rivers. There cotton is planted in March and April, blooms in June 

 and July, and perishes in November or with the frost. The earliest period at which 

 I have noticed the young worm was the last week in June, and its usual appearance 

 was in July, sometimes as late as the latter part of the mouth. Its date of appear- 

 ance was irregular, and. never accurately coincided in any two seasons. Sometimes 

 it seemed as though we were " not going to have any worm at all this year," a remark 

 suggested by hope and the tardiness of its advent. My observations have been mainly 

 directed to the question of the origination of the first brood, and have led me to re- 

 cord the following results : I have observed that the appearance of the worm in the 

 fields was always heralded by nights of the moth, which came to light in houses at least 

 a week before the worm was noticed on the plants. I have obserA'ed that the distri- 

 bution of the first brood was irregular, the worms occurring hero and there over miles 

 of country, while infesting some plantations, skipping unaccountably others, which 

 the second brood, however, seldom failed to reach. I have noticed that the worm was 

 always heard of to the southward at first, and never to the northward, of any given 

 locality in the cotton belt. Finally, after diligent search, no traces of the insect in 

 any stage could be found by me during the months preceding the appearance of the 

 first brood heralded by the moth, and after the cotton was above the ground. The 

 broods themselves were consecutive and without interruption so long as the condi- 

 tions were favorable. The last brood, in years where the worm was numerous, eat 

 up every portion of the plant that was at all soft, flowers, the persistent calyx, 

 the very young ball, the terminal shoots. The last brood of worms changed into 

 chrysalides in myriads on the leafless stems, clinging by their few threads as best they 

 might, and disclosed the moth in the face of the frost, many of the chrysalides per- 

 ishing. Afterwards, on sunny winter days, I have noticed the live moth about gin- 

 houses and fodder stacks, or the negro quarters. Was this a true "hibernation," or 

 merely an accidental survival f The locality and the condition seem to me alike arti- 

 ficial. 



Now, HUbner describes the moth of the cotton-worm at first as from Bahia. Suffi- 

 cient testimony to the identity of our insect with one destructive to the West Indian, 

 Mexican, and Brazilian perennial cotton is at hand, and the fact is established. In a 

 classificatory point of view the affinities of the cotton-worm are with Southern rather 

 than Northern forms of its family, as I have already pointed out. The conclusion to 

 which I have come with regard to the cotton-worm is that it dies out every year (with its 

 food plant), that it occurs in the cotton belt of the Southern States, and that its next appear- 

 ance is the result of immigration. Testimony is at hand to show that for many years 



