96 REPORT UPON COTTON INSECTS. 



room, hoping to hatch some moths for exposure. The following is the, result : In some 

 two weeks two moths came out ; they seemed delicate, and one lived only two days, the 

 othr four or five. No other moths have appeared. November 29, 1 fouud four Ichneu- 

 mon Hies out in box. December 2 one more, and December 7 another, the sixth, the 

 last, with no ovipositor. In breaking opeu the dried chrysalides, I destroyed two pupae 

 of parasites. These make eight parasites in some two dozen chrysalides; a large 

 proportion. I had 75 chrysalides in a box in summer ; about 50 came out moths ; most 

 of the others could not escape from and perished in the dried leaves. I saw not a par- 

 asite of any kind. 



The two following extracts from Professor Grote's letters also bear 

 upon this point : 



The cotton plant is now (November 21) stripped of leaves, except here and there at 

 the tops ; there is also a little new growth on the main stem. The worm appeared here 

 September 7, increasing in size and moi-e noticeable up to the 15th, when the earliest 

 webbing was noticed. The worm was not very numerous nor of even distribution. 

 The October brood was hardly noticed ; nevertheless, it must have existed, as I have 

 been finding chrysalides (not many) for the last few days wherever the leaf still held. 

 This shows that the last brood does not quit the plant, as I have formerly observed in 

 Alabama. Nevertheless, I searched a piece of wood and some fence-corners, as in- 

 structed, but found nothing. 



SAINT CATHERINE'S ISLAND, COAST OF GEORGIA, 



November 28, 1873. 



I think my observations go to show that the worm does not leave the plant for the 

 last or at any time. In Savannah I failed to find any traces away from the field. In 

 my former published observations in Alabama, I found the last chrysalides giving the 

 fly in the face of the frost. When the leaf fails, the worms web up any way possible 

 in the squares, or between the stem and the leaf stalks. They never leave the plant ; 

 in a few cases they spin up on weeds in the cotton rows. 



From the above-quoted correspondence and from other material, some 

 of which may be found in Appendix II, we feel warranted in stating- the 

 following conclusions respecting the disappearance of the last brood of 

 worms : In making preparations to undergo their tranformations, indi- 

 viduals of this brood do not differ in habits from those of the preceding 

 broods, except that, as the foliage of the cotton is frequently destroyed, 

 it becomes necessary for the worms to seek other places in which to web 

 up. Thus we see the worms webbing up, not only in the leaves of cot- 

 ton, but in the leaves of any plant that they can find, and even in the 

 crevices of bark ,of trees. Xo tendency on the part of the worms to 

 make a denser cocoon than those of the preceding broods was observed. 

 A large part of the pupae, which were enveloped in leaves of cotton, 

 became exposed and fell to the ground owing to the consuming of the 

 leaves by other larvae. Many such pupae would naturally fall prey to 

 predaceous insects or be destroyed by other causes. Thus we find, as 

 with the third crop, that a large proportion of this brood is destroyed 

 in a very short time after assuming the pupa state. The length of time 

 which individuals of this brood remained in the pupa state varied greatly ; 

 many moths emerged early in October, and a few emerged each day till 



