PACKARD.] 



THE COTTON ARMY-WORM. 



775 



The Hop Vine Root-Borer, Eepiahis mustelinus Packard.— This 

 moth is closely allied to the Eepiahis humiili of Europe, which bores in 

 the roots of the hop. Xo borer has yet been detected in our vines, but 

 it is uot improbable that the above-named species will be found to attack 

 this plant. It flies in Maine from the middle of July to the middle of 

 August. 



Description of the moth. — Female witli the body and wings sable-brown. Fore wings 

 with three broad silvery spots on the costa, margined with black ; a broad silvery line 

 along the internal margin, which is continued as a submarginal oblique straight line, 

 dislocated near the middle of the wing, and margined with yellowish-brown with some 

 black scales. A marginal series of triangular spots. Fringe dark at the base, spotted 

 externally with silver. Beneath, the body is yellowish-brown, as is the front edge of 

 the fore wings, which is banded with three dusky patches, the middle of the wing is 

 duskv, while the legs are dark externally. It expands a little over one and a quarter 

 (1.30) inches. 



Hepialus pulclier of Grote is a species which is common in the foot- 

 hills and mountains of Colorado during July, August, and September. 

 It may prove destructive to the hop when cultivated in Colorado. 



INJURING THE COTTON-PLANT. 



The Cottox Army-Worm, Aletia argiUacea Hiibner; Anomis xi/lina Say (Fig. 45). — 

 Feeding often in vast numbers upon the leaves of the cotton-plant ; a caterpillar with a 

 looping gait, hairy, green, dotted with black along a subdorsal yellowish line, and with 

 black dots beneath, changing to a pale reddish-brown moth. 



Although this moth, and especially the caterpillar, are so abundant 

 and destructive in the cotton-growing States, there is much that needs 

 to be known about its habits and transform- 

 ations, as good authorities differ. The follow- 

 ing account and illustrations are taken from 

 my " Guide to the Study of Insects," with 

 some additions from Eiley's Second Eeport 

 on the Noxious Insects of Missouri, and Mr. 

 Grote's account in Smith's Eeport on the 

 Geology of Alabama for 1875, p. 199. 



The parent of the cotton-worm is a red- 

 dish brown moth, with a dark discal oval 



spot centered by two pale dots. She de-Fic. 45.— Cotton Army-Worm, 



posits, according to Mr. Glover, a low, Egg, and Moth, 



much-flattened, vertically-ribbed egg upon the surface of the leaf. 

 " Each female moth deposits from 400 to 600, and, according to the 

 late Thomas Affbek, of Brenham, they hatch two days after being 

 deposited, if the weather be moist and warm. The worms at first 

 feed upon the parenchyma or soft, fleshy parts of the leaves, but 

 afterward devour indifferently, not only any portion of the leaves, but 

 also the blossom-bud and blossom, together with the calyx leaves at the 

 base of the boll, thus causing the lobes which hold the cotton to fall 

 entirely back and allow the cotton to drop at the slightest touch. While 

 young these worms readily let themselves down by a web when disturbed, 

 but when older they make less use of this web, and jerk themselves 

 away to a considerable distance when suddenly touched. They cast 

 their skins at five successive periods, and come to their growth in the 

 incredibly short space of fifteen or twenty days." 



The larva is a looper, four (the two foremost pair) out of the si.^teen 

 abdominal legs usually present in the family being wanting, so that the 



