hardwoods. In the Eastern and Southern States, the oaks, particularly those of the 
red oak group, are most heavily damaged. In the Prairie States, green ash is the 
chief host. Other hosts are black locust, elm, maple, willow, cottonwood, and 
occasionally fruit trees and ornamental shrubs (540). The adult is dark, slightly 
mottled, stout-bodied, and has grayish black hindwings. The female is lighter 
colored and considerably larger than the male and has a wingspread of 75 mm. The 
posterior half of the hindwing of the male bears a large yellowish to orange spot 
with a black border. Full-grown larvae are greenish white, nearly naked, bear 
simple setae, and are 50 to 70 mm long. The head is shiny brown and armed with 
powerful, nearly black mandibles. The thoracic legs are yellowish and _three- 
jointed, and each bears a curved, pointed tarsal claw. 
F-532850-54 
Figure 50.—The carpenterworm, Prionoxystus robiniae: 
A, adult male; B, adult female; C, eggs; D, larva; E, 
pupal cases. 
147 
