Explanation of Names
Author of family is
Latreille, 1804 (or
Leach, 1815?). See entry for genus
Lucanus for etymology.
Numbers
Nearctica.com lists nine genera for North America. (Those listed as
Pseudolucanus are now in the genus
Lucanus)
Identification
Medium to large, usually brownish or black beetles. Males of some species have spectacular jaws. Summary of family characteristics:
antennae with 10 segments, last 3-7 variously enlarged, often forming a club
antennae are jointed (
geniculate), in most North American genera, distinguishing them from antennae of Passalide
tarsal formula 5-5-5, tarsal claws equal in size
Antennae similar to those of
scarabs, ending in a club, but plates cannot be held tightly together. Examples:
Detail of legs, including tarsal segments and claws, of
Lucanus capreolus:
Males of some large species have spectacular jaws, most striking in
Lucanus elaphus:
Larvae are C-shaped, like those of scarabs and related families, see:
Larvae are associated with dead and rotting wood.
Stridulating organ present on hind (metathoracic) legs of larvae, which are not reduced as in
Passalidae. Anus longitudinal between 2 large, oval, often sclerotized (hard, dark) pads at end of body
(1). This last character differentiates them from
scarabs and related families.
Illustrated Key to Genera of North America (based on American Beetles (2)):
(Thanks go the contributors whose photos are used below.)
1. Antennae "elbowed" at end of first segment --> 2
- Antennae not "elbowed", but straight in its entirety. --> 6
2. Eye divided into upper and lower parts by
canthus (Lucanus has a short canthus). --> 3
- Eyes without dividing canthus. --> 4
3. Elytra smooth. -->
Lucanus (4 species)
- Elytra with stria and punctures. -->
Dorcus (2 species)
4. Hind tibia expanded at apex and spurs wide. Body convex. Western N.A. -->
Platyceropsis (1 species)
- Hind tibia and spurs slender. Body not convex, but flattened. Western and Eastern N.A. --> 5
5. Front of head broadly
emarginate. -->
Platycerus (4 species)
- Front of head not emarginate. -->
Platyceroides (7 species)
6. Short, oval beetles. Elytra noticeably hairy. -->
Nicagus (2 species)
- More elongate beetles. Elytra not hairy and with noticeable
stria. --> 7
7. Body more cylindrical. Male with conspicuous horn. Mandibles small. Northwest N.A. only. -->
Sinodendron (1 species)
- Not as cylindrical, more flattened. Neither sex having horn. Mandibles easily seen. Western and Eastern N.A. -->
Ceruchus (3 species)
Range
Worldwide in temperate and tropical areas.
Food
Adults may feed on leaves, tree bark, and aphid honeydew.
Life Cycle
Larvae feed on decaying wood. Pupation takes place in a cell of gnawed wood fragments
(1). Males often have enlarged jaws, used for fighting.
Remarks
Most of description of family is from Milne and Milne.
(3) They have excellent photos and descriptions of four North American species.
"Stag beetles discover new habitat.
Stag beetles are colonizing playgrounds and hiking trails covered with successive layers of hardwood woodchips. Maria Fremlin posts this fascinating news on her Web site:
http://maria.fremlin.de/stagbeetles/london_veluwe.html
… Jim McClarin, 11 February, 2006 - 9:19am"
See Also
Scarab beetles,
Scarabaeidae--note antennal structure with plates that can fold tightly
Ground beetles,
Carabidae--note thread-like antennae
Bark-gnawing beetles,
Trogossitidae
Passalidae--antennae lack "elbows"
Print References
Downie & Arnett (Vol 1) key and describe the Northeastern species.
(4)
Chu,
How to Know the Immature Insects, p. 87, fig. 209, illustrates larvae of
Lucanidae (1).
Milne and Milne, pp. 551-554
(3)
American Beetles, Vol. 2, Chapter 23
(2)
