Family: Scarabaeidae Subfamily: Scarabaeinae Genus: Onitis Species: Onitis vanderkelleni Lansberge, 1886
Total body length 18.0–26.0 cm (0.71–1.02 in). Body shape subquadrate posteriorly; may be caked in dried dung. Color dull black. Clypeal apex rounded to weakly sinuate. Frons with weak, central tubercle. Front tibia of male elongate, curving ventrally and inward at apex; female tibia somewhat shorter; tarsi lacking in both sexes. Tibia of middle leg gradually expanded to a triangulate apex. Hind trochanter lacking spine on posterior margin in both sexes. Hind femur of male with well-developed, posteriorly produced, straight spine; female lacking spine.
Undescribed. For Scarabaeinae (Ritcher, 1966): Grub C-shaped, hump-backed, cylindrical, cream-colored. Maxilla with galea and lacinia distinctly separate. Antennae with 4 or 5 apparent segments. Distal segment of antenna much reduced in size. Epipharnyx with tormae united mesally, anterior phoba present. Anal opening surrounded by fleshy lobes. Legs 2-segmented.
Africa. This species occurs in the tropical highlands of sub-Saharan Africa, with records from Angola, Burundi, Cameroon, Kenya, Rwanda, Tanzania, Uganda, and the Democratic Republic of the Congo (formerly Zaire) (Krikken, 1977). It usually occurs at elevations over 1,800 meters (5,900 ft) where rainfall ranges from 800–2,000 mm (31–79 in) per year (Edwards, 2007).
Poorly known. Related species of Onitis are dung burrowers. A vertical tunnel lined with dung is created under the initial dung source. Adult male and female beetles cooperate to transport dung pieces down the burrow where the dung is shaped into sausage-like masses. An egg (or eggs) is deposited into each of the dung sausages, and larval development occurs within the dung mass.
None. This species recycles dung and is beneficial for ranching and farming in Hawaii. Being a dung feeder, this species poses no threat to crop or ornamental plants. Additionally, this species is not a threat to native dung beetles because none are known from Hawaii or Guam.
Established. Onitis vanderkelleni was released in 1976 at Parker Ranch on Big Island (Nakao and Funasaki, 1979) where it is now established (Nishida, 2002). Like most of Hawaii's dung beetles, this species was introduced to help control populations of the horn fly (Haematobia irritans), a biting pest of livestock.
Not established or recorded. There are no records of this species from Guam.
In Hawaii, this species was intentionally introduced.
Three species of Onitis are recorded from Hawaii (none are known from Guam). Onitis vanderkelleni can be separated from the other Onitis species by examination of the middle tibia (O. vanderkelleni with gradually expanded middle tibia with a triangulate apex versus O. phartopus with an abruptly expanded tibia with trapezoidal apex), the hind trochanter (O. vanderkelleni hind trochanter lacking spine-like process versus trochanter with a well-developed spine in male O. phartopus), hind femur of male (O. vanderkelleni with a posteriorly produced, straight spine versus O. alexis with a curved spine and O. phartopus that lacks a spine), and color (O. vanderkelleni dull black versus greenish-black with brown elytra in O. alexis).
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