INSECT ENEMIES OF EASTERN FORESTS 541 
inoffensive. ‘The few terrestrial species are scavengers living in de- 
caying vegetable matter and manure. Blackman and Stage (46) re- 
ported several specimens of an undetermined species bred from well- 
decayed hickory. 7 
FamMity BIBIONIDAE 
The March Flies 
The Bibionidae, or March flies, are awkward appearing, usually 
with a somewhat flattened head, stout legs, and many-jointed antennae. 
Malloch (288) stated that the larvae differ from all other species in 
having the false segment behind the head fully developed and armed 
with spinose processes. The prothoracic spiracles are apparently on 
the second segment, and metathoracic spiracles are also present. Most 
of the species are scavengers and feed on decaying vegetable matter, 
whereas others attack the roots of grass and plants. Plecia ameri- 
cana Hardy was bred by Hardy (209) from larvae living in rotting 
wood, and an undetermined species was bred from decayed hickory 
by Blackman and Stage (46). 
Famity CLUSIIDAE (HETERONEURIDAE) 
The flies of the family Clusiidae are small, with large heads and 
broad wings, the latter usually marked with black or brown. The lar- 
vae are slender, cylindrical, and somewhat thickened posteriorly, and 
the body segmentation is indistinct. Some of the species are able to 
spring a short distance into the air, as do certain cecidomyids and 
sepsids. The species are scavengers living in rotten wood and be- 
neath the bark of trees. Sobarcephala (Clusinodes) flaviseta John. 
has been recovered in large numbers from a rotten tree stump, and 
a species of clusiid has been reported as often present under the bark 
of dead trees and in decaying wood. 
SAWFLIES, ANTS, WASPS, AND BEES 
Orper HYMENOPTERA 
The order Hymenoptera (meaning membrane-winged) is one of 
the largest and most important orders of the insects. It includes a 
vast number of species, many of which have extraordinary instinctive 
faculties and social habits. The bees, wasps, and ants are among the 
better-known types. A great many are parasitic in habit, some cause 
the growth of galls on plants, and many others, in the larval stage, 
feed on the foliage of plants or bore into the stems of herbaceous 
plants or into branches or trunks of trees. They undergo a complete 
metamorphosis. 
A few species are wingless, but the order is characterized by its 
winged members, having four membranous wings. The fore pair are 
large and more completely veined than the hind pair, although in 
some species the venation is greatly reduced. ‘The mouth parts are 
formed for biting, but some are also adapted for lapping or sucking 
liquid food. The first segment of the abdomen is fused with the 
metathorax. Each female is equipped with an ovipositor, which may 
be modified for sawing, piercing, or stinging. 
