Full-grown larvae are greenish with light or blackish heads and 
distinct lateral lobes, and measure less than 12 mm. long. Each 
body 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 winter is 
spent in cocoons in the ground. There is usually one generation a 
year, but some species occasionally have a partial second. 
FAMILY ARGIDAE 
ARGID SAWFLIES 
The family Argidae is represented by eight genera and 32 
species in the United States and Canada, the majority of which 
occur in the Eastern States. The adults are medium- to small- 
sized, stout-bodied sawflies. They can be recognized by their 
three-segmented antenna, the third segment of which is very long 
and sometimes U-shaped or Y-shaped. The more common species 
are also usually either 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 rather thick-set, widest on ab- 
dominal segments one to three, tapering toward the rear end, 
and the venter is flattened. 
The birch sawfly, Avge pectoralis (Leach), is widely distributed 
in the Northeastern States and southern Canada. Its preferred 
hosts are various birches, especially gray and paper. It also has 
been recorded feeding on willow. Full-grown larvae are about 18 
mm. long. The head is reddish-yellow with a spot on each side; 
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 full-grown larvae 
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 States are as follows: Arge clavi- 
cornis (Fab.)—willow, birch, and azalea; A. scapularis (Klug) — 
elm and birch; A. coccinea (Fab.)—sumac; Sterictiphora pruni- 
vora (Dyar)—cherry; and Arge sp.—elm and oak. 
FAMILY CIMBICIDAE 
CIMBICID SAWFLIES 
The family Cimbicidae is represented in the United States and 
Canada by 12 species, some of which have been recorded feeding 
on trees in the Eastern States. The adults are large; the antennae 
are clavate with an abrupt enlargement at the tip. 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. During life they are covered with a 
waxy bloom. 
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