Copris incertus

Beneficial

Common name(s)

black dung beetle, uncertain dung beetle

Taxonomy

Family: Scarabaeidae Subfamily: Scarabaeinae Genus: Copris Species: Copris incertus Say,1835

Adult diagnosis

Total body length 12.0–20.0 mm (0.47–0.78 in). Body shape oval; may be caked in dung. Color shiny black. Head of major male with long, thin, well-developed horn; reduced in minor male; horn truncate to lacking in female. Pronotum with four horn-like protuberances in major male; protuberances much reduced in minor male and female. Elytra with 9 striae; 8th stria incomplete, never reaching posterior margin of elytra.

Larval diagnosis

Undescribed. For Copris spp. (Ritcher, 1966): Grub C-shaped, hump-backed, cylindrical, whitish. Maxilla with galea and lacinia distinctly separated. Epipharynx with tormae united mesally, anterior phoba present. Antenna 4-segmented, distal segment much reduced in size. Legs with small, blunt claws each bearing a terminal seta. Prothoracic shield with an anteriorly projecting, angular process on each side. Venter of last abdominal segment with paired, median, caudal lobes or a cleft median lobe.

Native range

Mexico, Central and South America. This species is distributed in the New World tropics from Veracruz, Mexico south through Central America and into Colombia and Ecuador (Palestrini et al., 1990).

Plant host(s)

None. This species feeds on dung as both an adult and larva. There are no records of Copris incertus feeding on live plant tissues.

Life history

(Halffter et al., 1994): The female creates a burrow that terminates in a brood chamber under or near a dung pat. With the aid of the male, dung is relocated into the brood chamber, brood balls are created, and the burrow is sealed. On average, five brood balls are created and an egg is laid within each. The larvae grow and feed within the dung balls, and the maternal female remains in the brood chamber and continues to apply dung to the surface of the ball. She also repairs damaged brood balls and drives away parasites. Loss of the maternal female results in greatly increased larval mortality.

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 to combat the horn fly (Haematobia irritans), a biting pest of livestock. It was released in 1922-1923 (Hawaii Division of Forestry, 1923) on all the major islands of Hawaii and is now widely established (Nishida, 2002).

Status in Guam

Recorded, not established. This species was released on Guam in 1953 to help control populations of the horn fly (Haematobia irritans), a biting pest of livestock (Peterson, 1956). Peterson (1956) stated that it was likely established on the island. Yet, neither Cartwright and Gordon (1971) nor Bourquin (2002) reported it from Guam, and no specimens are present in the University of Guam insect collection (pers. obs. 2015).

Potential distribution and dispersal pathway

In both Hawaii and Guam, this species was intentionally imported.

Similar species

This scarab is extremely similar to the closely related Copris remotus. These Copris species are separated by examining the elytra (C. incertus with the outer 8th stria incomplete, not reaching the posterior elytral margin versus Copris remotus with the 8th stria complete, reaching the posterior elytral margin).

Other names (synonyms)

Copris denticornis Gemminger and Harold, Copris exadius Gemminger and Harold, Copris prociduus Say

Report your observation

Report your observation of this beneficial species at our iNaturalist project.

Copris incertus male; photo by E.L. Engasser

Copris incertus male; photo by E.L. Engasser

Copris incertus male; photo by E.L. Engasser

Copris incertus male; photo by E.L. Engasser

Copris incertus male; photo by E.L. Engasser

Copris incertus male; photo by E.L. Engasser

Copris incertus male; photo by E.L. Engasser

Copris incertus male; photo by E.L. Engasser

Copris incertus female; photo by E.L. Engasser

Copris incertus female; photo by E.L. Engasser

Copris incertus female; photo by E.L. Engasser

Copris incertus female; photo by E.L. Engasser

Copris incertus female elytral striae, lateral view; photo by E.L. Engasser

Copris incertus female elytral striae, lateral view; photo by E.L. Engasser

Copris incertus male genitalia, dorsal view; photo by E.L. Engasser

Copris incertus male genitalia, dorsal view; photo by E.L. Engasser

Copris incertus male genitalia, lateral view; photo by E.L. Engasser

Copris incertus male genitalia, lateral view; photo by E.L. Engasser

distribution map for Copris incertus

distribution map for Copris incertus