154 



ENTOMOLOGY. 



spotted, or mahogany brown. The more destructive forms are 



the spring canker-worm, Anisopteryx vernata, in which the females 



are wingless, and lay their eggs in patches on the bark, the worms 



appearing when the trees leaf out. In cities the caterpillars of 



Eudalimia subtly naria Hiibner defoliates elms and other shade-trees. 

 Family Noctuidae. The owlet moths, number upwards of 1500 



species in this country, many of which 



are destructive to crops. The noctuids 



in general differ from other moths in 



their thick bodies, the thorax often 



being crested, by their stout palpi, and 



the usually simple antennas, though 



these are in some cases pectinated. 



The fore wings are rather narrow, with 



usually a dot and reuiform spot in the 



middle of the wing, while the hind 



wings are large. They mostly fly by 



night. The caterpillars are usually 



smooth, without hairs or spines, the 



body tapering towards each end, and 



more or less striped; the number of feet 



is usually sixteen, except the lower 



genera with broad wings, such as Cato- FIG. 189. Hop-snout moth, Hy- 



cala, which are semiloopers, having but P ena humuli - Natural size - 



fourteen feet. The pupae are usually subterranean. 

 The lower forms, called Deltoids, have very long palps, and the 



larvae are slender, glassy green, and fall wriggling to the ground 



when disturbed. Such is Hypena humuli Harris. The species of 



Catocala have very broad fore wings and often bright red hind wings, 



the caterpillars living on trees. The great Erebus odora Drury, 

 which expands five inches, and the great 

 Thysania agrippina (Cramer) of Brazil are the 

 giants of the family. Among the most de- 

 structive pests are the cotton-worm (Aletia 

 argillacea Hiibuer), the boll-worm (Heliolhis 

 armigera Linn.), and the northern army -worm 



FIG. 190. Army-worm and moth. ., male moth; b, abdomen of female nat. 

 size; c, eye; d, base of male antenna; e, base of female antenna, enlarged. 



(Leucania unipuncta Haw., Fig. 190). Universal pests are the cut- 

 worms, which like most of the other larvae of the group feed by night, 

 hiding by day. Their eggs are laid near the roots of grass, and the 



