364 EEPORT 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 exclusiv^^ly 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) 

 wben 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 TEANSFOKMATIONS. 



The Egg (Plate III, Fig. 1; Plate lY, Fig. 1).— The ^gg of Heliothis 

 is 7°^"^ in diameter, its axis being about equal to its greatest diameter, 

 which is near the base. In color it is nearly white, rather inclined to 

 yellowish, and is easily detected against tbe 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 ISGG, 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 eojg is generally deposited singly on the outside of the involncel 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-batched caterpillar; but after 

 a careful examination of several hundred stems I found only one egg placed in 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 tbe 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 nlso upon the 

 involucre. Occasionally, too, an egg is to be found on the stem of the 

 boll or upon a leaf petiole. During tbe hot weather of Jul}' 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 tlying in great numbers. 

 f ■ ■ 



*This statement was contained iu a report prepared by Professor French, for the 

 Third Report of the United States Entomological Commission, but wLich has been in- 

 dependently printed iu the Eleventh Report of thf^ St'ito Entomologist of Illinois. 



