40. Lasius bicornis (Forster, 1850) Figs. 147, 148.
Formica bicornis Forster, 1850:41.
Worker. Clear citron yellow. Funiculus segments not longer than broad; scape distinctly flattened. Outline of petiole characteristic: high, tapering dorsally with a deep emargination. Body hairs long, longest hairs nearly as long as maximum hind tibial width, sparse on dorsum of gaster where restricted to posterior borders of tergites; genal hairs sparse, scapes and tibiae bare. Length: 4.0-4.5 mm.
Queen. Yellowish brown to brown with head wider than alitrunk. Characters as worker; size relatively small. Length: 4.8-5.3 mm.
Male. Dark brown; petiole high, tapered and deeply indented; gaster hairs very sparse. Length: 4.0 mm.
Distribution. Rare; Sweden: Sm. (Forsslund, 1957a). - Range: Central and South Europe from Pyrenees and Caucasus but also recorded from Himalayas (Kashmir), South Italy to Netherlands; uncommon.
Biology. This species nests in rotten logs. Alatae have been taken in September (Poldi, 1962).