Onthophagus comperei

Status

Beneficial

Common name(s)

Compere's dung beetle

Taxonomy

Family: Scarabaeidae Subfamily: Scarabaeinae Genus: Onthophagus Species: Onthophagus comperei Blackburn, 1903

DNA barcode

none available

Adult diagnosis

Total body length 7.0–9.0 mm (0.27–0.35 in). Body shape oval; may be caked in dung. Color shiny black. Small to medium-sized Onthophagus, over 6 mm. Clypealclypeal:
of, or referring to, the clypeus
apexapex:
point or edge furthest from the body
of major male produced and strongly recurvedrecurved:
bending backwards
; not produced or recurvedrecurved:
bending backwards
in minor male and female. Head of major male with 2 sinuatesinuate:
gently curved (specifically of margins or edges); often in reference to the clypeus
, vertically-oriented horns, apexapex:
point or edge furthest from the body
of horns weakly bifurcatebifurcate:
a process dividing into two points
, no ridge between horns, horns variable in size; minor male and female with 2 tubercles near base of head. Ocular canthuscanthus:
a process extending over and sometimes dividing the eye
not completely dividing eye. Pronotumpronotum:
the dorsal surface of the thorax
with anterioranterior:
the front or forward; opposite of posterior
angles curved weakly outward; surface lacking distinct process in either sex. Front tibiatibia:
a segment of the leg articulated with the tarsus and femur
of male somewhat slender, female tibiatibia:
a segment of the leg articulated with the tarsus and femur
comparatively more stout. Scutellumscutellum:
the triangular portion of the thorax between the bases of the elytra
absent.

Larval diagnosis

Undescribed. For Onthophagus spp. (Ritcher, 1966Ritcher, 1966:
Ritcher P. 1966. White grubs and their allies: a study of North American scarabaeoid larvae. Oregon State University Monographs, Studies in Entomology 4: 1-219.): Grub C-shaped, hump-backed, cylindrical, and cream-colored. Maxillamaxilla:
set of paired mouthparts located posterior to the mandibles
with galeagalea:
outer branch or lobe of the maxilla
and lacinialacinia:
inner portion of the maxilla
distinctly separate. Epipharynxepipharynx:
lobe on the interior surface of the labrum or clypeus
with tormaetormae:
in scarab larvae, sclerotized structures on the ends of the clypeolateral suture extending towards the mesal line
united mesallymesally:
at or near midline of body
, anterioranterior:
the front or forward; opposite of posterior
phoba present. AntennaeAntennae:
paired sensory organ on head, formed from numerous segments
4-segmented, distaldistal:
situated away from the point of articulation, thus usually furthest from the body
segment much reduced. Legs 2-segmented. Prothoracic shieldprothoracic shield:
the chitinous plate behind the head of larvae
without anteriorly projecting processes. Third abdominal segment bearing a prominent conical, dorsaldorsal:
of or relating to the upper surface; opposite of ventral
gibbosity covered with numerous short, stout setaesetae:
small, hair-like structure
.

Native range

Australia. This species is native to Queensland, Australia. It has been recorded from the Townsville area southward to the Stewart River (Matthews, 1972Matthews, 1972:
Matthews E. 1972. A revision of the Scarabaeine dung beetles of Australia. I. Tribe Onthophagini. Australian Journal of Zoology Supplementary Series 19: 3-330.).

Plant host(s)

None. This species feeds on dung as both an adult and larvalarva:
the immature form of an insect; in scarabs, also called grub or white grub; preceded by the egg stage, followed by the pupal stage
. There are no records of this beetle feeding on live plant tissues.

Life history

This nocturnal species is recorded from tropical savannahs and open woodlands (Matthews, 1972Matthews, 1972:
Matthews E. 1972. A revision of the Scarabaeine dung beetles of Australia. I. Tribe Onthophagini. Australian Journal of Zoology Supplementary Series 19: 3-330.). Life history is poorly known, but related Onthophagus species are dung tunnelers, with females creating a burrow under or near dung (Woodruff, 1973Woodruff, 1973:
Woodruff R. 1973. The scarab beetles of Florida (Coleoptera: Scarabaeidae) part I. The Laparosticti (Subfamilies: Scarabaeinae, Aphodiinae, Hybosorinae, Ochodaeinae, Geotrupinae, Acanthocerinae). Arthropods of Florida and Neighboring Land Areas 8: 1-220.). The burrow is then provisioned with dung in the form of brood balls. Each ball is impregnated with an egg; larval development occurs within the brood ball.

Pest potential

None. This species recycles dung and is beneficial for ranching and farming in Hawaii. Primarily being a dung feeder, this species has never been recorded damaging crop or ornamental plants. Additionally, this scarab is not a threat to native dung beetles because none occur in Hawaii or Guam.

Status in Hawaii

Recorded, not established. This species was intentionally brought to Hawaii in 1921, though it is appears no specimens were released (Hawaii Division of Forestry, 1923Hawaii Division of Forestry, 1923:
Anonymous. 1923. Report of the entomologist. Hawaii Board of Commissioners of Agriculture and Forestry. Division of Forestry. Honolulu, HI: Hawaiian Gazette Company.).

Status in Guam

Not established or recorded. There are no records of this species from Guam.

Potential distribution and dispersal pathway

In Hawaii, this species was intentionally imported.

Similar species

This scarab could be confused with other Onthophagus species of similar coloration and small to medium-size (more than 6 mm): Onthophagus binodis, Onthophagus incensus, Onthophagus armatus, Onthophagus cuniculus and Onthophagus laminatus.

Major males of these species can most readily be distinguished by examining the head armature (O. comperei with two sinuatesinuate:
gently curved (specifically of margins or edges); often in reference to the clypeus
, vertically-oriented, weakly bifurcatebifurcate:
a process dividing into two points
horns versus O. binodis lacking horns, O. cuniculus lacking horns but with pairedpaired:
in relation to bilateral symmetry: occurring on both sides of the body
tubercles at base of head, and O. incensus, O. armatus and O. laminatuswith non-bifurcate horns).

Females are somewhat more difficult to distinguish, but can nonetheless be separated by examining the base of the head (O. comperei with two tubercles versus O. binodisand O. cuniculus with a slightly curved ridge, O. laminatus and O. incensus with a transversetransverse:
extending horizontally across a surface
ridge, and O. armatus with a feebly bisinuatebisinuate:
possessing two sinuate edges or portions, with two curves
ridge), the pronotal process (O. comperei female without a process versus O. binodis with a small lobe-like process, O. cuniculus with a bi-lobedbi-lobed:
possessed of two lobe-like structures
process) and the pronotal anterioranterior:
the front or forward; opposite of posterior
angles (O. comperei with the anterioranterior:
the front or forward; opposite of posterior
angles rounded versus O. cuniculus and O. laminatuswith the anterioranterior:
the front or forward; opposite of posterior
angles curved outward).

Other names (synonyms)

None known

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