Antennaeantennae:
paired, segmental appendages, borne one on each side of head, functioning as sense organs and bearing a large number of sensilla.
11-segmented with a distinct, 2-segmented club. Antennal setation sparse. Subantennal groovessubantennal groove:
groove or concavity lying below the antennal insertion and housing the base of the antenna. Placed between the eye (if present) and the mandibular articulation, and sometimes extends below or behind the eye.
absent or present and open internally (former Stephaniolus species). Eyes small, reduced, coarsely faceted. Pronotal discpronotal disc:
the area of the pronotum which is visible dorsally and usually delimited laterally by the two lateral carinae. Contrasted with the paired pronotal hypomera, which extend onto the ventral surface.
convex, lateral margins emarginateemarginate:
notched at the margin.
, or simple (former Stephaniolus species). Procoxal cavitiesprocoxal cavities:
external closure: Externally closed when the postcoxal processes of the hypomera meet the prosternal process or meet one another.
open. Metacoxaemetacoxae:
the coxae of the metathorax.
moderately separated, separation slightly less than metacoxal length. Elytraelytron:
the fore wing in Coleoptera, which is more or less uniformly sclerotized and in resting position is longitudinally oriented, usually meeting the opposite elytron along the midline.
with distinct striae composed of coarse, nearly confluent puncturespuncture:
a small impression on the cuticle, like that made by a needle.
. Tarsal formulatarsal formula:
the number of tarsomeres on the fore, mid, and hind tarsi, respectively.
4–4–4. Dorsal surface with curved, recumbent setaeseta:
a sclerotized, hairlike (or scalelike) projection of cuticula arising from a single trichogen cell and surrounded at the base by a small cuticular ring.
, or sparsely covered with hair-like setae (former Stephaniolus species) .
The genus Coxelus is similar to Megataphrus in having reduced eyes and wingswing (hind wing):
wings arising from the metathorax. NOTE: In many Zopherinae, the hind wings are completely absent.
absent. The distinctive antennal cavitiesantennal cavity:
a prothoracic cavity for housing the whole antenna or a portion of the antenna (usually the club).
on the hypomeronhypomeron:
that portion of the pronotum which is visible from the ventral side; when there is a lateral pronotal carina, this is the portion below that carina (the pronotal disc being above it).
serve to distinguish Megataphrus, and the presence of subantennal groovessubantennal groove:
groove or concavity lying below the antennal insertion and housing the base of the antenna. Placed between the eye (if present) and the mandibular articulation, and sometimes extends below or behind the eye.
serve to distinguish the former Stephaniolus species.
Coxelus longus (Stephan, 1989Stephan, 1989:
Stephan KH. 1989. The Bothrideridae and Colydiidae of America north of Mexico (Coleoptera: Clavicornia and Heteromera). Occasional Papers of the Florida State Collection of Arthropods. 6: xii + 65 pp.), C. serratus Horn, 1885Horn, 1885:
Horn GH. 1885. Contributions to the coleopterology of the United States. No.4. Transactions of the American Entomological Society. 12:128–162, illus.
Southern coastal range of California, high-elevation mountains of Southwestern United States (SE AZ).
Likely occurs in: Southwestern United States (NM). High-elevation mountains.
Members of this genus have been found on the bark of old pine stumps. Coxelus serratus have been collected sifting duff from Redwood trees, as well as under the bark of Douglas fir.
Abundance: Rarely encountered.
Coxelus longus: Absence of subantennal groovessubantennal groove:
groove or concavity lying below the antennal insertion and housing the base of the antenna. Placed between the eye (if present) and the mandibular articulation, and sometimes extends below or behind the eye.
. Distribution: Arizona, USA
Coxelus serratus: Presence of subantennal groovessubantennal groove:
groove or concavity lying below the antennal insertion and housing the base of the antenna. Placed between the eye (if present) and the mandibular articulation, and sometimes extends below or behind the eye.
. Distribution: California, USA
Horn (1885)Horn (1885):
Horn, G.H. 1885. Contributions to the coleopterology of the United States. No.4. Transactions of the American Entomological Society, 12: 128-162, illus., Ivie (2002a)Ivie (2002a):
Ivie, M.A. 2002a. 127. Colydiidae, pp. 445-453 In: R. H. Arnett, Jr., Jr. and M. C. Thomas (eds.), American Beetles. CRC Press, Gainesville, Florida., Stephan (1989)Stephan (1989):
Stephan, K.H. 1989. The Bothrideridae and Colydiidae of America north of Mexico (Coleoptera: Clavicornia and Heteromera). Occasional Papers of the Florida State Collection of Arthropods, 6: xii + 65 pp.
Authors: Lord NP, Nearns EH, Miller KB. 2011–2015.
Content updated Apr 2015; taxonomy updated Feb 2026
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