416 



LEPIDOPTERA 



CHAP. 



leaves of aspen and lives between them, an unusual habit for 

 Noctuid larvae. When about to pupate it bores into bark or 

 soft wood to change to a pupa, Fig. 205 ; 

 the specimen represented closed the hole 

 of entry by placing two separate doors 

 of silk across the burrow, as shown at d. 

 The anal armature of this pupa is ter- 

 minated by a curious transverse process. 

 The systematic position of this inter- 



FIG. 204. Brephos notha. Adult larva. 



FIG. 205. Brephos notha. A. 

 Pupa, ventral aspect ; B, 

 extremity of liody, magni- 

 fied ; C, the pupa iu wood ; 

 (f, diaphragms constructed 

 by the larva. 



esting Insect is very uncertain : Meyrick and others associate it 

 with the Geometridae. 



The larva of Leucania unipunctata is the notorious Army- 

 worm that commits great ravages on grass and corn in Xorth 

 America. This species sometimes increases in numbers to a con- 

 siderable extent without being observed, owing to the retiring- 

 habits of the larvae ; when, however, the increase of numbers 

 has been so great that food becomes scarce, or for some other 

 cause for the scarcity of .food is supposed not to be the only 

 reason the larvae become gregarious, and migrate in enormous 

 swarms : whence its popular name. The Cotton-worm, Aletin 

 xylinae is even more notorious on- account of its ravages. Biley 

 states x that in bad years the mischief it commits' on the cotton 

 crop causes a loss of 6,000,000, and that for a period 

 of fourteen successive years the annual loss averaged about 

 3,000,000. This caterpillar strips the cotton plants of all but 

 their branches. It is assisted in its work by another highly 

 destructive Noctuid caterpillar, the Boll -worm, or larva of 

 Heliothis armigera, which bores into the buds and pods. This 



1 Fourth Rep. U.S Ent. Commission, 1885, p. 3. 



