LIBRARY

776
COLLEGE ENTOMOLOGY
consist of swarms (Empis, Hilara, Rhamphomyia, and other genera) that move
up and down over the surface of land and water. They are predacious on small
insects and other invertebrates, and some are bloodsuckers. There are a number
of accounts of the interesting courting reactions of males of a number of
species which offer newly captured prey to 1.he female. Those of J-lilara have
the basal segment of the fore tarsi 1 enlarged and functional as a spinning gland
from which many threads of silk may be drawn to make webs or balloons to
capture living prey which is offered to the female. In Europe Eltringham (1928)
has listed eight species of Hilara, the males of which spin silk as indicated. The
commonest of these is H. maura Fab. whose habits are described by Hamm
(1928). Empis aerobatica Melander of North America blows a bubble around
the morsel offered the female, and E. j)oplitea Loew, also of North America, is
known as the balloon-making fly. They occur in well-watered areas in woods
and along streams, and a number of species visit flowers.
The most important genera are CheliJera Macquart (European, North
American), Drapetis Meigen (European, North American, Australian), Empis
Linn., }!iZara Meigen, and Rhamphomyia Meig. (Holarctic and Australian),
Meghyperus Loew and Ragas Walker (European), Trichina Meig. and Wiedemannia
Zeiterstedt (European, North American).
The family, consisting of some 1,600 species, is generally distributed through.
out the world.
Family DOLICHOPODIDJE Leach 1819 (Dol'i-cho-pod'i-dre, from the Greek
OOALXDS, long, + 7fOVS, foot; referring to the long legs). German, Langbeinfiiegen.
Long-legged Flies, Long-headed Flies, Dolichopodids.
Minute to small, 1-11 mm. long; slender, long-legged, and some long-headed
flies; smooth; normally with bristles on the head, thorax, and legs; black, gray,
or yellow and usually brilliant metallic green, blue, coppery, golden, and silvery.
Males often with specially ornamented head, antennro, palpi, wings, or
legs.
Head hypognathous; wider than thorax; normal or elongated in some genera.
Eyes large, holoptic in males and covering most of head. Antennre three-segmented;
arista dorsal or apical; bare or plumose in males; segment III may be
elongated in males and tuberculate in females. Proboscis short, fleshy, retractile;
labella large, fleshy. Thorax may be depressed in front of scutellum. Wings
hyaline or clouded; venation simple; discal and basal cells confluent; sixth
vein present or absent. Squamre reduced. Legs medium to long; coxre short;
tibire may be modified and brightly colored; fore tarsi of male often ornamented
with large dark or bright apical tufts; claws, pulvilIi, and empodia
small. Abdomen five- to six-segmented; variously shaped; cylindrical, conical,
compressed dorsally or laterally. Hypopygium of male small and concealed or
large, conspicuous, and complicated. Larvre slender, cylindrical, 12-segmented,
mostly amphipneustic with abdominal spiracles very small; head very small;
I Members of the order EMBIOPTERA also have the basal segment of the fore tarsi modified
for spinning silken webs which are used chiefly for lining their burrows and passagewaya.