302 REPOKT UPON COTTON INSECTS. 



from a brilliant green to a deep pink or a dark brown, exhibiting almost 

 every conceivable intermediate stage, and from an immaculate, uustriped 

 specimen to one with regular spots and many stripes. The green worms 

 are more common than those of any other color ; but those of varying 

 shades of pink er brown are so abundant as to make it impossible to fix 

 upon a type. Early in the season, as will be hereafter shown, the pre- 

 vailing color is green. A common variety is light green in color. Kun- 

 ning from the first ring back of the head to the posterior end of the body 

 on each side is a broad whitish line; just above is a broad dusky line; 

 down the center of the back is another dusky line, or stripe, as it 

 should preferably be called; this dorsal stripe has a narrow white line 

 down its center, and it is bordered on each side by a narrow white line. 

 Between the dusky dorsal and lateral stripes run four or five very 

 faint, wavy, longitudinal, white lines, so faint as not to interfere with 

 the general color of the body. Each body-ring has eight black spots, 

 which, upon being examined with a lens, are seen to be tubercles, each 

 with a stiff hair upon its tip. These spots are arranged in two transverse 

 rows of four, the spots in the front row being slightly closer together than 

 those in the back row ; the outer spot of the back row is small and 

 placed nearer the front row. 



Of these features the most constant seems to be the whitish stripe on 

 each side. When the boll-worm is brown these stripes assume a yellow- 

 ish hue. They are shown in all illustrations of the boll-worm yet pub- 

 lished, and are present in all specimens in the department collection. 

 Another pretty constant feature is the relative position of the tubercles 

 just described. They are not always of a contrasting color to the rest 

 of the back, and hence cannot always be spoken of as spots. When 

 they are not discernible as spots, however, an examination with the lens 

 shows them still present as tubercles, each surmounted by a hair. This 

 point affords apparently a good and reliable means of distinguishing the 

 young boll-worm from the young cotton-worm, which otherwise might 

 prove a matter of difficulty during the earlier stages and in the early 

 part of the year, before black cotton-worms are to be found. In the 

 cotton- worm the two middle spots of each of the two rows of four are of 

 the same distance apart, so as to form the four corners of a rectangle. 

 In the boll-worm, however, the two middle spots of the hind row are 

 more widely separated than the corresponding spots of the front row. 

 This distinction may be recognized at a glance, when the eye has become 

 accustomed to it. The dusky dorsal stripe is often wanting, as also are 

 the dusky lateral stripes, and, as just stated, the spots are often indis- 

 cernible. 



Mrs. Treat seems to have noticed a uniformity of color as between 

 individuals of the same brood, and a diversity as between those of dif- 

 ferent broods. She says: 



I did not think that this green larva that eats into the pease and stalks of corn, be- 

 fore the latter arc half grown, was, as you inform me, this same striped boll-worm 

 that eats into the ears of corn. * * * 



