LIBRARY

680 COLLEGE ENTOMOLOGY'
feeding others. The red myrmicine ant, Myrmica rubra (Linn.), 3-6 mm., has
five European subspecies and four North American subspecies and eight varieties.
It tends homopterous insects, the larvre of lycrenid butterflies, and is also
carnivorous. M. scabrinodis Nyal is also well represented by a number of
varieties in Europe and North America. The little red, brown, yellow house
ant or Pharaoh's ant, Monomorium pharaonis (Linn.), 2-4 mm., an Old World
species now widely distributed by commerce, is a household pest wherever it
occurs and does not come into competition with the Argentine ant. Like most
ants, it is said to prey upon termites.
Certain of the fire ants belonging to the genus Solenopsis are serious garden
and orchard pests. The commonest European species is S. jugax Latr" while
S. geminata Fab. S. aurea Wheeler, S. molesla Say, and S. texana Emery are
well known throughout North and South America and are most annoying in
tropical areas. The workers are 0.5-2.5 mm. long while the Queens are 6-7 mm.
in length. They tend mealybugs, and at least one species has been known to
strip the living bark from young citrus trees in southern California.
Subfamily FORMICINlE 1 Ashmead 1901 (For-mi/ci-me, from the Latin
formica, an ant). Typical Ants.
This is one of the largest and most important subfamilies of ants. The
members are variable in size, ranging from 2-20 mm. in length and averaging
FIG. 238. The herculean carpenter ant, Campanatus hl!7Cu/eanus pennsylvanicu5 DeGeer,
a large black species common in eastern North America. (After Back, U.S. Bur. Ent., 1937.)
about 7 mm. Antennae nine- or more-segmented. Mandibles broad and dentate
or slender and pointed. Maxillary palpi three- to six-segmented. Abdomen with
one-segmented pedicel; without constriction between segments I and II of the
gaster; all segments visible from above; anal or cloacal orifice circular, terminal,
and surrounded by a fringe of hairs; sting vestigial and nonfunctional; odorous
glands absent; male genitalia not retractile. Pupre usually enclosed in a cocoon,
some naked. Workers not conspicuously polymorphic.
The family is widely distributed, and many genera are cosmopolitan, but the
lCAMPONOTINlE Forel of authors.