536 MISC. PUBLICATION 657, U. S. DEPT. OF AGRICULTURE 
style or arista. The larvae resemble the Therevidae, from which they 
may be separated by their smaller size. Larvae of Omphrale fenes- 
tralis (1u.) have been taken from rotten wood, bird nests, fungi, and 
from the roots of plants. The species is said to be predaceous on larvae 
of other insects. | 
Famiry RHAGIONIDAE (LEPTIDAE) 
Snipe Flies 
The Rhagionidae, or snipe flies, are moderate-sized, bristleless flies 
with vestigial squamae. The antennae consist of three joints, the third 
not annulated. The marginal vein encircles the wing. The species 
may be either scavengers or predators. Species of Rhagio and Chry- 
sopilus (fig. 128, A) have been found under dead leaves and in tree 
pockets, where they probably live as scavengers. Phachicerus nitidus 
John. is recorded from the decayed trunk of a sycamore. Larvae of 
Symphoromyia spp., on the other hand, live in the soil. The latter 
are annoying flies, persistently flying about one’s head and occasionally 
attacking one. 
A subfamily, the Xylophaginae, 1s composed of slender species 
closely allied with the Rhagionidae, but differing in that the third 
antennal segment is annulated and the marginal vein does not reach 
beyond the “anal angle of the wing. The eyes of the male are sepa- 
‘ated, and the scutellum is unspined. The larvae, which live under 
the bark or in the soil, are said to be predaceous on other insect larvae. 
Larvae of Erinna lugen Loew (fig. 128, G) have been found in large 
numbers associated with Saperda tridentata under elm bark. Larvae 
of Merchantha contracta Beauv. have been taken from under bark of 
chestnut, pine, hickory, and oak that were infested with cerambycids. 
E. abdominalis Loew has been taken from under the bark of pine, 
where it was feeding on beetle larvae. 
Famiry LONCHAEIDAE 
The Lonchaeidae are small shining black flies about 5 or 6 mm, in 
length. The oral vibrissae are absent, the cross veins are never ap- 
proximated, the auxiliary vein and basal cells are complete, the tibiae 
have preapical bristles, the ovipositor is elongate and sword-shaped, 
and the propleura is bare above the bristle. The larvae are slender, 
and except for the anterior segments, clothed with minute spines. 
The penultimate segment is free of conical processes, and the stig- 
matic tubes are small and wartlike. 
The species of this family may be either scavengers or predators. 
Lonchaea polita (Say) has been bred a number of times from beetle- 
infested elm wood, and the species is believed to be predaceous on bark 
beetle larvae. It has also been bred from beetle-infested hickory wood, 
from old pumpkin vines, cabbage stalks, and butternut hulls. Accord- 
ing to MacAloney (278), ZL. corticis Taylor was one of the most im- 
portant enemies of the white-pine weevil. ZL. marylandica Mall. has 
been bred from a larva taken under bark. 
SPECIES CHIEFLY SCAVENGERS OR FUNGIVOROUS 
Under this heading may be included a vast number of the Diptera, 
the habits and immature stages of which are but little known. Cer- 
