4i6 



LEPIDOPTERA 



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. , , , „— lagri^H- 3 



The anal armature of this pupa is ter- KIj i iKaHffflir ~ 



minated by a curious transverse process. 



The systematic position of this inter- 



FiG. 204. — Breplws notha. Adult larva. 



Fig. 205. — Brephos notlicc. A, 

 Pupa, ventral a.spect ; B, 

 extremity of body, magui- 

 iied ; C, the pupa in wood ; 

 d, diaphragms coustructed 

 by the larva. 



esting Insect is very u.ncertain : Meyrick and others associate it 

 with the Geometridae. 



The larva of Leucania uniiiunctata is the notorious Army- 

 worm that commits great ravages on grass and corn in North 

 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 micrrate in enormous 

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

 xylinae is even more notorious on account of its ravages. Eiley 

 states ■^ 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 armigeva, which bores into the buds and pods. This 



' Fourth Bep. U.S Ent. Commission, 1885, p. 3. 



