segment bears transverse rows of slight tubercles armed with short, stiff setae. The 
larvae feed gregariously on the foliage of oak, butternut, hickory, hawthorn, and 
pecan, and occasionally are abundant enough to attract attention. Adults appear in 
May and June; larvae are present from June to August, and overwinter in cocoons in 
the ground. There is usually one generation per year, but some species occasionally 
have a partial second. 
Family Argidae 
Argid Sawflies 
The family Argidae is represented by 8 genera and 59 species in the United 
States and Canada, the majority of which occur in the Southwestern United States 
(697). The adults are medium- to small-size, stout-bodied sawflies. They can be 
recognized by their three-segmented antennae, the third segment of which is very 
long and bifurcate in males of some groups. The more common species are usually 
reddish brown or bluish black, with more or less dark-brown wings. Larvae are 
yellowish green or red and are usually spotted. The body is often rather thick-set, 
widest on abdominal segments one to three, tapering toward the rear end, and the 
venter is often flattened. 
The birch sawfly, Arge pectoralis (Leach), 1s widely distributed in eastern North 
America. Its preferred hosts are various birches, especially gray and paper. It also 
has been recorded feeding on willow and alder. Full-grown larvae are about 18 mm 
long. The head is reddish yellow; the body yellowish, with six rows of black spots 
on top and three on each side. Adults appear during June and July and deposit their 
eggs in slits cut in the margins of leaves. Larvae are present from July to September, 
and winter is spent as prepupae in cocoons spun in the litter on the ground. The 
species is of no economic importance, although it occasionally becomes abundant 
enough to cause noticeable defoliation over limited areas. 
Additional species of argid sawflies likely to be encountered on trees and shrubs 
in the Eastern United States are: A. clavicornis (F.)—on willow, birch, hawthorn, 
plum, hornbeam, and azalea; A. scapularis (Klug)—on oak, alder, elm, and birch; 
A. coccinea (F.)—on sumac; A. abdominalis (Leach)—on birch and azalea; A. 
humeralis (Beauvois)—on poison-ivy and poison-sumac; and Sterictiphora spp.— 
on plum and cherry. 
Family Cimbicidae 
Cimbicid Sawflies 
The family Cimbicidae is represented in the United States and Canada by 3 
genera and 12 species, some of which have been recorded feeding on trees in the 
Eastern States (697). The adults are large with clavate antennae. The tibiae are 
without preapical spurs; however, there are single apical spurs on the front tibiae. 
Full-grown larvae have large heads, and their bodies taper toward the rear, and they 
are sometimes covered with a waxy bloom. 
The elm sawfly, Cimbex americana Leach, is the largest of the North American 
sawflies. It is widely distributed, occurring from coast to coast in southern Canada 
and throughout the United States. The larvae feed primarily on the foliage of elm 
and willow, but are also observed occasionally on basswood, birch, maple, poplar, 
and alder. The antennae of adults are tinged with orange; the head and thorax, 
black; the wings, smoky brown; and they are about 25 mm long. The female’s 
abdomen is usually steel blue, with three or four yellowish spots on each side and a 
faint, whitish spot near the thorax. In the male, the whitish spot near the thorax is 
distinct, but there are no yellowish spots on the sides. Full-grown larvae are 
yellowish white or greenish white with a pebbly skin and a black dorsal stripe, and 
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