LIBRARY

750 COLLEGE ENTOMOLOGY
esses, and filaments may also be present. in aquatic species; terrestrial, semiaquatic,
or aquatic.
The females oviposit in the soil- a process that can be easily observed in
late summer and autumn - or the eggs may be laid elsewhere in t.he larval
habitat. The larvre are phytophagous and bore into dead decaying wood; or
feed upon the roots and tops of grasses or cereals; on dead and decayed vegetable
matter in the soil or water; on fungi, mosses, and similar plants; and as leaf
miners on living plants. Terrestrial forms prefer damp places, and the larvre
of many species appear during the rainy season.
The family is a large one, consisting of some 300 genera and over 8,500 species
distributed throughout the world, being most numerous in the temperate
regions. Species occurring in the polar regions and at high altitudes are often
brachypterolls or wingless. The family is divided into three subfamilies and
five tribes (Curran, 1934). In size the adults vary from the small apterous
snow gnat or snow fly, Chionea nivicola Doane, 4 mm. long, of North America,
to such large species as the North American Holorusia rubiginosa Loew, 35 mm.
long, wing expanse 55 mm., the Australian Longurio dux Hudson, 40 mm.long,
wing expanse 75 mm., and the still larger Chinese Tipula bro/)(lignagia Westwood,
which has a wing expanse of 100 mm. The most beautiful species are the
black and orange-red Australian Clytocosmus helmsi Skuse, and C. tillyardi
Alexander, 35 mm.long, which mimic certain wasps of the genus Eumenes.
The snow gnats appear on the snow in winter and are extremely hardy, living
in the northern pari of North America and also at high altitudes. Chz'onea valga
Harris is our commonest species. The leaf-eating crane fly, Cylindrotoma
sPlendens Doane, 9-10 mm., oviposits in the tissues of false bugbane upon
which the larva'! feed. It ranges into Alaska. The range crane fly, Tipula
simplex Doane, 8-13 mm., has wingless females, and the larVa! live in holes
in the soil and feed upon native grasses and planted cereals in California.
Many other species of this genus have similar habits. The Iarvre of the giant
crane fly, Holorusia rubiginosa Loew, referred 1.0 above, live among the roots
and stems or in the mud of water plants in slow-running streams and in ponds
of the Pacific coast. They are extremely large, up to 55 mm. in length. Larvre
of the North American genus Antocha Osten Sacken inhabit silken cocoons
attached to rocks in swift streams. Larvre of the genus Aphrophila live in vegetation
and debris in the mist and spray of waterfalls in Australia.
Tipula oleraeea Linn., T. paludosa Meigen, and Pachyrhina maeulosa Meigen
all injure root crops and bulbs in Europe.
Closely related families: TANYDERID.tE or primitive crane flies are chiefly
Australian, the larvre of which are aquatic or subaquatic and live in the sand
at the margins of streams. Two genera and three species are North American.
PTYCHOPTERID.tE are false crane flies of North America whose larvre have
a very long caudal respiratory tube and live in saturated humus. The adults,
called phantom crane flies, are the most delicate and ephemeral members of
the grouP. having long downy black legs with conspicuous white bands and
enlargements of the basitarsi which are referred to as gas bags by Edwards