368 REPOfcT 4, UNITED STATES ENTOMOLOGICAL COMMISSION. 
bruised spot, which is the first manifestation of the rot, is simply the 
result of the gnawings of the worm in its attempt to penetrate the boll 
at that point. Bolls thus spotted were, as he repoits, watched until 
in every case the rot supervened. 
In spite of the confidence with which Mr. Stelle puts forth this theory, our 
experience would indicate that he is mistaken. In fact we have learned 
to question the trustworthiness of his statements. We have repeatedly 
seen bolls badly gnawed both by Aletia and by the Boll Worm, as well 
as by other Lepidopterous larvae, which yet were sound and good inside, 
and we believe the cases mentioned by Mr. Stelle to have been simply 
coincidences. We may also adduce the fact that the gnawings of the 
worms into tomato and Phvsalis, fruits which rot very easily, seldom if 
ever produce rot. The only decay actually caused by the Boll Worm to 
the cotton boll occurs where the seed-cavity has been pierced and rain 
has been enabled to enter. 
Many instances of the carnivorous propensities of the Boll Worm have 
been met with during the past few years. We have known the larger 
worms (and the act has been repeatedly seen by observers in the employ 
of the Commission) to seize upon the smaller worms, biting through the 
skin and feeding upon the juices of the body. And this has not only 
been done in the confined breeding jars, but upon the cotton plant, in 
open air, with an abundance of vegetable food at hand. Professor Willet, 
as we learn from his correspondence with us, has also noticed the same 
occurrence with these worms when feeding upon tomato, and Judge 
Johnson has noticed the same habit among the corn-feeding worms. 
More interesting, however, than this, even, is the habit which the Boll 
Worm has of occasionally preying upon the pupse of Aletia. This was 
observed we think for the first time by Mr. Trelease while in the employ 
of the Department of Agriculture during the summer of 1879, at Selma, 
Ala. He says : 
Owing to its tough integument, the pupa of Aletia seems to be freer from insect 
attack than the larva is, yet even its hard skin does not always save it. About the 
middle of August I firs*" noticed what appeared to be an anomalous preparation for 
pupation in the boll-worm (Heliothis armigera), for I found several full-grown larva- 
of this species with leaves closely webbed around them, precisely as Aletia webs tip 
before changing to a pupa. An examination of one of these leaves, however, showed 
me that the boll-worms had not webbed them about themselves, but had insinuated 
themselves into leaves folded and preoccupied by Aletia, the latter having already 
passed into the pupa state, and they bad done this for the express purpose of feeding 
on these pupa 1 . Many canes of this sort were seen. 
Judge Johnson gives the following very interesting account of this 
habit in his report of observations : 
Though almost omnivorous, Heliothis larvae are essentially pod borers and seed 
eaters. They will take to anything having tho appearance of a pod. This is curi- 
ously manifest in their preference for the chrysalides of other Lepidoptera. Tlie 
larger worms would leave everything for tbe pupa} of Aletia when they were plenti- 
ful. This special omnivorous appetite was first noticed Septemuer in company 
ivifch Professor Jones, whilst we were experimenting in a field infested with Aletia;. 
