Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada

Family Lucanidae - Stag Beetles

Unknown beetle - Ceruchus striatus Stag Beetle - Lucanus elaphus - female Platycerus marginalis Falls Creek Falls beetles - Platyceroides laticollis Cottonwood Stag Beetle - Lucanus mazama - male Cottonwood Stag Beetle - Lucanus mazama - male Dorcus parallelus? - Dorcus parallelus  Lucanus capreolus  - Lucanus capreolus
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Coleoptera (Beetles)
Suborder Polyphaga (Water, Rove, Scarab, Long-horned, Leaf and Snout Beetles)
Superfamily Scarabaeoidea (Scarab, Stag and Bess Beetles)
Family Lucanidae (Stag Beetles)
Other Common Names
Pinching Bugs
Explanation of Names
Lucanidae Latreille 1804
38 spp. in 8 genera of 3 subfamilies in our area, ~1500 spp. in 109 genera worldwide(1)
8-60 mm
Medium to large, usually brownish or black beetles. Males of some species have spectacular jaws. Summary of family characteristics:
antennae 10-segmented, last 3-7 variously enlarged, often forming a club
antennae are jointed (geniculate), in most North American genera, distinguishing them from antennae of Passalidae
tarsal formula 5-5-5, tarsal claws equal in size
Antennae similar to those of scarabs but with a looser club

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 of C-shaped scarabaeoid type, with stridulating organ on hind legs, which are not reduced as in Passalidae. Anus longitudinal between 2 large, oval, often sclerotized (hard, dark) pads(2), unlike in related families

Illustrated Key to North American Genera adapted from(3)

1. Antennae elbowed at end of first segment --> 2

- Antennae not elbowed, but straight in its entirety. --> 5

2. Eye divided into upper and lower parts by a canthus (canthus short in Lucanus). --> 3

- Eyes without dividing canthus. --> 4

3. Elytra appearing smooth, punctures fine. --> Lucanus (4 spp.)

- Elytra with distinct stria and larger punctures, except in male majors of D. brevis. --> Dorcus (2 spp.)

4. Front of head distinctly, broadly emarginate. Male mandibles complex with internal teeth. Females winged. --> Platycerus (5 spp.)

- Front of head not strongly emarginate. Male mandibles simply blade-like (as in females). Females wingless. --> Platyceroides (16 spp.)

5. Body short, oval. Elytra noticeably hairy. --> Nicagus (2 spp.)

- Body elongate. Elytra not hairy and with noticeable stria. --> 6

6. Body more cylindrical. Male with conspicuous horn, female with sharp tubercle. Mandibles small. nw. NA --> Sinodendron (1 sp.)

- More flattened. Neither sex having horn. Mandibles conspicuous. w. & e. NA --> Ceruchus (3 spp.)

see also(4)
Worldwide; most NA spp. associated with forested areas
Normally woodlands. One species found in Texas sand dunes. Others associated with driftwood along bodies of water. Larvae mostly in decaying wood.
Life Cycle
Larvae feed on decaying wood. Pupation takes place in a cell of gnawed wood fragments(2). Males often have enlarged jaws used for fighting.
See Also
Scarabaeidae (club plates can fold tightly)
Passalidae (antennae not elbowed)
Carabidae (antennae thread-like)
Trogossitidae (antennae not elbowed)
Print References
Grossi P.C., Paulsen M.J. (2009) Generic limits in South American stag beetles: taxa currently misplaced in Sclerostomus Burmeister (Coleoptera: Lucanidae: Lucaninae: Sclerostomini). Zootaxa 2139: 23-42 (Abstract)
Internet References
Fact sheet (Thomas 2005)(5)
Works Cited
1.Paulsen M.J. (2013) Annotated checklist of the New World Lucanidae (Coleoptera: Scarabaeoidea)
2.How to Know the Immature Insects
Hung-Fu Chu, Laurence K Cutkomp. 1992. Wm. C. Brown Publishers.
3.American Beetles, Volume II: Polyphaga: Scarabaeoidea through Curculionoidea
Arnett, R.H., Jr., M. C. Thomas, P. E. Skelley and J. H. Frank. (eds.). 2002. CRC Press LLC, Boca Raton, FL.
4.The stag beetles of Oklahoma (Coleoptera: Lucanidae)
Arnold D.C., Drew W.A. 1987. Proceedings of the Oklahoma Academy of Science 67: 27-29.
5.University of Kentucky Department of Entomology (2004-2010) Kentucky critter files