LIBRARY

770
COLLEGE ENTOMOLOGY
lower ones smaller, males holoptic or dichoptic. Scutellum bare or hairy.
Tibire with or without spurs; fore pair with one, two, or none; hind pair with
one or two. Pulvilli present. Empodia vestigial, narrow or pad-like. Wings
hyaline or with fuscous spots; venation distinct; usually five (rarely four)
posterior cells; discal cell present or absent; costa extending around tip of
wing; rom distinct; squamre absent or present, sometimes vestigial. Larvre
variable with small, partially exserted head which is prolonged in Xylophagus;
maxillary palpi well developed; mandibles long, vertical, protrusile, simple or
hooked; body H-segmented and with pseudopods. Aquatic forms flattened and
Sc
FIG. 280. Wing of the large apiocerid fly, Raphiomidas xmzthos Townsend.
with two round protrusile blood gills on the last segment below the long anal
filaments. Terrestrial forms generally cylindrical; with simple or spines
pseudopods on the fifth or on each abdominal segment; lateral spine-like fila"
ments sometimes present; segments X and XI each with a row of hooklets in
Vermileo; last segment with hairy process; spiracles present. These flies frequent
wooded areas near fresh water. Aquatic forms inhabit fresh water and
are predacious on small aquatic animals. Terrestrial species are likewise
predaciOUS and live under bark of trees, in dung, fungi, soil, and wood. Members
of the remarkable genus Vermileo excavate conical pits in the sand and
dust at the bottom of which they lie concealed to capture and feed on the
ants that they entrap in much the same manner as ant lions. That two widely
separated groups of insects with such amazing structural differences should
occupy exactly the same niche in nature is remarkable. Especially is it astonishing
that such a simple, helpless-looking creature as this fly larva should
simulate the accomplishments of so well-equipped, active, and formidable a
gladiator as is the ant lion. The larvre of the so-called worm-lions, Vermileo,
construct smaller and steeper sloping pits than those of their rivals, but they
are often very numerous. In the protected side of a giant granite boulder in
the Yosemite Valley, CaliL, the author counted upwards of a thousand of
these contiguous pits. The Sierra worm-lion, Vermileo comstocki Wheeler,
occurs in the Sierra Nevada Mountains at an altitude of 4,000 to 9,000 ft.
Members of the genera Lampromyia Macquart and Vermitigris Wheeler are
closely related to Vermileo, and the larvre and adults are quite similar in habits
and appearances. Species of Lampromyia have been taken in most of the Span-