LIBRARY

706
COLLEGE ENTOMOLOGY
somewhat resembling the honeybees; the glossa or tongue is shorter than the
mentum and there is dense pubescence on the head and thorax. The hind legs
are equipped with a pollen-gathering apparatus on the enlarged mid-tarsal segments;
hind tibire are two-spurred; fore wings have two or three cells. They are
solitary or colonial in habits, the individual females constructing their own bur­
rows and cells in the ground and provisioning the latter with nectar and pollen.
FIG. 254. An acute-tongued or burrowing
bee of the gentls Andrcna. (After
Woodworth from Illsects of Western North
America.)
Their colonies are often very extensive
and may include many thousand nests.
There are one or two broods a year and
both sexes remain in the nests throughout
the late summer and winter and
emerge in the spring. Pupre may also survive
the winter. Sexual dimorphism is
expressed in differences of coloration, the
males often having yellow faces. Stylopization,
which often occurs among these
bees, causes marked changes in their appearance
and produces a reversal of normal
sexual colorations.
This is a large cosmopolitan family,
reaching its highest development in the
Holarctic region and but poorly represented
in Australia. The adults are of
great value to agriculture because of their pollen- and nectar-gathering and their
·fertilization or pollination of plants. Some species are rather restricted in the
flowers they visit. They are particularly fond of the pollen and nectar of plants
belonging to the great families CRUCIFERlE, COMPOSIT fE, ROSACEfE,
LEGUMINOSiE, and UMBELLIFERiE, but visit the plants of many other
families.
The hairy-legged mining bee, Dasypoda hirtipes (Fab.), 10 mm.long, dark with
an abundance oflong yellow and orange pile, is one of the most beautiful European
species and a valuable pollinizer of plants. It nests in sandy places along the coast
of southern England and sinks vertical shaft.s one to two feet deep at the bottom
of which two to five cells are excavated and provisioned with pollen paste.
The members of the genus Andrena Fab. are abundant in Europe and North
America and are among the commonest bees in the fields; meadows, and brushlands.
Andrena miserabilis flavoclypeata Smith, A. nasoni Robertson, A. winkleyi
Viereck, A. vicina Smith, A. forbesi Robertson, A. weedi Viereck, A. hiPpotes
Robertson, and A. bradleyi Viereck are all important pollinizers of fruits
and berries in eastern North America.
The families NOMAD IDlE (Fallen 1813) Kirby 1837, MELECTIDlE
Schmiedeknecht 1882, and STELIDIDJE (Schenk 1859), Schmied. 188,J are
parasites or inquilines in the nests of other bees. The members of the family
PANURGIDlE Schmied. 1882 are pollen and nectar gatherers, resembling
members of the ANDRENIDfE in habits.