SS <oY 
D 
A,B,C,D, F-531248 
E, F-500619 
Figure 80.—Elm spanworm, Ennomos subsignarius: A, 
adults mating (male distinguished by feathery 
antennae); B, eggs; C, light-colored larva; D, dark- 
colored larva; E, pupae (light larvae and pupae 
develop in low-density populations, darker from dense 
populations). 
Pero honestaria (Walker) occurs on black locust, pin cherry, and larch in the 
Eastern States. Full-grown larvae are about 37 mm long and dark brown, with paler, 
longitudinal markings. The head is bilobed and the body increases in girth toward 
the rear. There appears to be two generations per year. P. morrisonaria (Henry 
Edwards) occurs on a wide variety of trees, including fir, spruce, larch, pine, 
willow, and aspen. The species is single-brooded and occurs from Nova Scotia 
south to Virginia and west to the Pacific Coast (434). 
197 
