364 REPORT 4, UNITED STATES ENTOMOLOGICAL COMMISSION. 
specific study of this insect for a year or two, for enough has been said 
to show that it is a very general feeder. 
In this connection we cannot avoid making the statement that the 
Boll Worm is by no means exclusively vegetarian in its diet, although 
this point will be fully discussed in the special report. It has been re- 
peatedly known to devour the pupae of the Cotton Worm (Aletia xylina) 
when free upon the plants, and has moreover gained a wide reputation 
as a cannibal, the larger individuals frequently dining upon the smaller 
ones. 
CHARACTERS AND TRANSFORMATIONS. 
The Ego (Plate III, Fig. 1; Plate IV, Fig. 1).— The egg of Heliothis 
is 7 mm in diameter, its axis being about equal to its greatest diameter, 
which is near the base, \n color it is nearly white, rather inclined to 
yellowish, and is easily detected against the green background of leaf, 
stem, or involucre. Upon certain of the eggs shortly after being laid 
there appears a reddish-brown band near the summit, which disappears 
with the growth of the embryo. The worm itself can be seen through 
the semi-transparent shell as it approaches the hatching point. The 
sculpture of the egg — the polar ribs with their cross-furrows — is almost 
identical with that of Aletia. 
The only published statement we have ever seen as to the number of 
eggs laid by a single moth was by Glover, who, in 18GG, stated that a 
correspondent had dissected a female moth and found it to contain 
more than 500 eggs. 
Mr. Glover, misled by some cause or other, makes the following state- 
ment concerning the place of deposit of the eggs: 
The egg is generally deposited singly on the outside of the involucel or outer calyx 
of the flower or young boll, where it adheres by means of a gummy substance which 
surrounds the egg when first laid, and which hardens by exposure to the atmosphere. 
It has been repeatedly stated by planters that the egg was deposited on the stem, and 
that the young stem forms the first food of the newly-hatched caterpillar; but after 
a careful examination of several hundred stems I found only one egg placed iu this 
situation, and that from the fact of its being laid on its side instead of the base, had 
evidently been misplaced. 
The truth of the matter is that the eggs are to be found on all parts 
of the plant, more, perhaps, being deposited on the under side of the leaf 
than elsewhere. A few can be found on the stalks, and many on the 
upper surface of the leaves, and quite a large proportion also upon the 
involucre. Occasionally, too, an egg is to be found on the stem of the 
boll or upon a leaf petiole. During the hot weather of July and August 
by far the greatest number will be found on the under side of the largest, 
darkest leaves. The favorite time for oviposition is at or just after 
twilight, when the moths can be seen flying in great numbers. 
* This statement was contained in a report prepared by Professor French, for the 
Third Report of the United states Entomological Commission, but which has heen in- 
dependently printed in the Eleventh Report of the State Entomologist of Illinois. 
