83 



about the middle of July. The female moths evidently do not distribute 

 their e«;f;s, but deposit them in lar«i;e numbers on comparatively small 

 areas, and the caUMpillai-s hatchino; ai-<' likely to overtax their food sup- 

 ply, and thus to be forced to migrate in search 

 of more. On this account they are sometimes 

 called fall army-worms, although they do not 

 move in fixed directions and in conspicuous 

 armies like the army-worm, properly so callefl, 

 but tend to spread in all directions from an 

 overstocked area. 



This ai)pears to have been originally a 

 tropical insect, and it now ranges from Brazil 

 across Central America to the West Indies 

 and throughout the United States. Cater- 

 pillars are occasionally found destructively Fig 

 numerous as far north as New York and the ft^l'^^otetTetes. "kaS 

 upper peninsula of Michigan, and the adult ^''^' 

 moth has been taken in Montana, Minnesota, Maine, and Canada 

 has also l)een collected in California and Arizona. 



61. The Grass- worm, 

 ■aphygma frugiperda: a, adult; 



It 



Fig. 02. The Wheat- head 

 Army-worm, Leucania albilinea: 

 a, a, larvif, h, eggs, both natural 

 size; c, d, eggs enlarged, top and 

 side views. 



THE WHEAT-HEAD ARMY WORM. 



Leucania albilinea Hiibn. 

 (Heliophila albilinea.) 



This caterpillar (Fig. 62, a, a) differs from 

 the common army-worm especially in its 

 peculiar preference for the heads and seeds 

 of grasses and small grains. It is often 

 seriously injurious to these crops, and also 

 sometimes does considerable harm to corn 

 by burrowing down into the growing top of 

 the plant. Larva) taken here and there in 

 the corn field feeding in this way were bred 

 by us to this species in two different years. 

 Miss Murtfeldt found it doing great dam- 

 age to corn, sorghum, and small grain in 

 1888, sweet corn especially being seriously 

 and generally injured. It may be easily 

 distinguished from the army-worm, which 

 it closely resembles, by its more slender 

 form and larger head, by the straight dark 

 bands each side the middle of the head 

 (Fig. 63), and by the clear-cut narrow brown 

 and yellowish lines on the sides of the body. 



