Stag Beetle, the common name of the family Iucanidoe, of the lamellicorn pentamerous Coleoptera, of which the type is the genus lu-canus (Linn.). Many of the species are of considerable size, and have received their name from the large and powerful mandibles with which the males are furnished. The stag beetle of Europe (L. cervus, Linn.) is 2 in. long, exclusive of the mandibles, and is the largest and most formidable of the British beetles; the color is black, with brown elytra; the head is wider than the body; the mandibles corneous, arched, with three large and several smaller teeth, and used as instruments of offence; antennas bent, pectinated, and 10-jointed, tibiae dentated along outer edge, and the tarsi ending in two hooks. They live in the trunks of trees by day, flying abroad at night, often into houses; the females are smaller, with narrower head and much shorter mandibles. They are also called horn beetles and flying bulls. According to De Geer, they feed principally on the sweet juice spread over the leaves of the oak and exuding on the bark, which they obtain by means of the brushes of the under jaws; they are said to seize caterpillars and soft-bodied insects, and to suck their juices; they are very strong, and can pinch the finger pretty hard, but do not use their mandibles in this way unless provoked, and their punctures are not poisonous; they live only a short time in the perfect state, perishing soon after laying their eggs in the crevices of bark near the roots of trees.
The larva) are large and fleshy grubs with very thick body, arched, with 13 rings, and having a brown scaly head armed with two strong jaws with which they gnaw wood, reducing it to a coarse powder, and often doing much damage by boring into the trunks and roots of oaks and beeches; there are six scaly feet, attached to the first three rings; they are said to be six years in coming to their growth, and by some are regarded as the cos-sus of the Romans, a worm-like grub, according to Pliny, obtained from the oak and considered delicious food. The largest of the New England species is the L. capreolus (Linn.), usually called horn bug; it is about 1¼ in. long, without the mandibles, the latter being sickle-shaped and toothed; the body mahogany brown, smooth and polished. They appear in July and August. The larvae are 3 in. long when full grown, straw-colored, with yellow head, brown jaws, and nine stigmata; they live in the trunks and roots of apple trees, willows, and oaks, and are sometimes injurious.
European Stag Beetle (Lucanus cervus).