Onthophagus oklahomensis

Beneficial

Common name(s)

Oklahoma dung beetle

Taxonomy

Family: Scarabaeidae Subfamily: Scarabaeinae Genus: Onthophagus Species: Onthophagus oklahomensis Brown, 1927

Adult diagnosis

Total body length 2.0–4.1 mm (0.07–0.16 in). Body shape oval; may be caked in dung. Color shiny black. Size tiny, under 6 mm. Clypeal apex rounded, never emarginate; female with frontoclypeal suture very feeble, male suture indistinct. Head without horns or tubercles. Ocular canthus not completely dividing eye. Scutellum absent.

Larval diagnosis

Undescribed. For Onthophagus spp. (Ritcher, 1966): Grub C-shaped, hump-backed, cylindrical, and cream-colored. Maxilla with galea and lacinia distinctly separate. Epipharynx with tormae united mesally, anterior phoba present. Antennae 4-segmented, distal segment much reduced. Legs 2-segmented. Prothoracic shield without anteriorly projecting processes. Third abdominal segment bearing a prominent conical, dorsal gibbosity covered with numerous short, stout setae.

Native range

Southeastern U.S. This species is native to the U.S., where it is found from western Texas and central Kansas eastward to Virginia and southern Florida (Woodruff, 1973).

Plant host(s)

None. This species feeds on dung as both an adult and larva. There are no records of this scarab feeding on live plant tissues, although adults will feed on rotting fruit (Woodruff, 1973).

Life history

(Woodruff, 1973): This species is often associated with sandy habitats where adults feed on dung, rotting fruit, and fungus. Specimens have been collected on human, dog, and cattle feces. Females dig a shallow burrow 2.50–7.6. cm (1.0–3.0 in) near or under dung. Within the burrow, dung is formed into brood balls in which larval development occurs. Developmental time from egg to adult is about three weeks.

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 species is not a threat to native dung beetles because none occur in Hawaii or Guam.

Status in Hawaii

Established. In Hawaii, this species was imported in 1963 to combat the horn fly (Haematobia irritans), a biting pest of livestock. Specimens were released at Ewa on Oahu (Davis and Krauss, 1964).

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 tiny scarab is extremely similar to the closely related Onthophagus tuberculifrons and superficially similar to small specimens of Leconte's dung beetle (Ateuchus lecontei). These three species are separated by examining the clypeus (O. oklahomensis with clypeus entirely round versus O. tuberculifrons with an emarginate or bidentate clypeus, and A. lecontei with a bidentate clypeus) and tubercles of the head (O. oklahomensis lacking tubercles versus O. tuberculifrons with paired tubercles).

Other names (synonyms)

none known

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Onthophagus oklahomensis male; photo by E.L. Engasser

Onthophagus oklahomensis male; photo by E.L. Engasser

Onthophagus oklahomensis male; photo by E.L. Engasser

Onthophagus oklahomensis male; photo by E.L. Engasser

distribution map for Onthophagus oklahomensis

distribution map for Onthophagus oklahomensis