Canthon indigaceus

Beneficial

Common name(s)

tumblebug

Taxonomy

Family: Scarabaeidae Subfamily: Scarabaeinae Genus: Canthon Species: Canthon indigaceus Leconte, 1866

Adult diagnosis

Total body length 8.5–12.0 mm (0.33–0.47 in). Body shape round (dorsal view); may be caked in dried dung. Color dark metallic green. Eyes crescent shaped; longer than wide. Clypeus bidentate; surface smooth, never coarsely granulate. Pronotum and elytra smooth, never coarsely granulate. Front tibia with apical spur bifurcate in male and spine-like in female (spur may be worn down in older individuals). Middle and hind legs elongate. Pygidium width less than twice height.

Larval diagnosis

Undescribed. For Canthon spp. (Ritcher, 1966): Grub C-shaped, hump-backed, cylindrical, whitish. Anal slit transverse. Prothoracic shield with anterior projecting, angular process on each side. Legs each with a single long, terminal seta surrounded by numerous short setae; 2-segmented; without stridulatory structures; claws absent.

Native range

Southwestern U.S., Mexico, Central America. In the U.S., this species is known only from Arizona and Texas (Robinson, 1948). It occurs through much of Mexico, with its distribution extending south to Costa Rica (Solis-Blanco, 2002).

Plant host(s)

None. This species is primarily a dung feeder and has not been recorded feeding on live plants. However it has been observed tumbling the rinds of prickly pear (Opuntia spp.) fruit (Novelo et al., 2007), suggesting opportunistic feeding on fallen fruit.

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 attacking 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. Canthon indigaceus was intentionally introduced to Hawaii. Specimens were released in 1954 at Weima on Kauai, Molokai Ranch on Molokai, and the University of Hawaii Dairy on Oahu (Weber, 1955). Similar dung beetle introductions were undertaken to help control populations of the horn fly (Haematobia irritans), a biting pest of livestock (Markin and Yoshioka, 1998).

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 released.

Similar species

This scarab is one of four Canthon species recorded from Hawaii (none are known from Guam). It is distinguished from the other Canthon species recorded in Hawaii by examination of the pronotal texture (texture smooth in C. indigaceus versus coarsely granulate in C. pilularius ), color (metallic dark green in C. indigaceus versus dark blue-black in C. humectus, shining green or red in C. viridis, velvety black to green in C. pilularius), size (C. indigaceus 8.5–12.0 mm [0.33–0.47 in] versus 2.0–4.0 mm [0.08–0.16 in] in C. viridis, 12.0–19.0 mm [0.39–0.59 in] in C. pilularius), and pygidium shape (pygidium width less than twice the height in C. indigaceus versus width more than twice the height in C. humectus).

Other names (synonyms)

Canthon chevrolati Harold, Canthon chiapas Robinson

Report your observation

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Canthon indigaceus male; photo by E.L. Engasser

Canthon indigaceus male; photo by E.L. Engasser

Canthon indigaceus male; photo by E.L. Engasser

Canthon indigaceus male; photo by E.L. Engasser

Canthon indigaceus female head, dorsal view; photo by E.L. Engasser

Canthon indigaceus female head, dorsal view; photo by E.L. Engasser

Canthon indigaceus male foretibia; photo by E.L. Engasser

Canthon indigaceus male foretibia; photo by E.L. Engasser

Canthon indigaceus female foretibia; photo by E.L. Engasser

Canthon indigaceus female foretibia; photo by E.L. Engasser

Canthon indigaceus female pygidium, caudal view; photo by E.L. Engasser

Canthon indigaceus female pygidium, caudal view; photo by E.L. Engasser

Canthon indigaceus male genitalia, caudal view; photo by E.L. Engasser

Canthon indigaceus male genitalia, caudal view; photo by E.L. Engasser

Canthon indigaceus male genitalia, lateral view; photo by E.L. Engasser

Canthon indigaceus male genitalia, lateral view; photo by E.L. Engasser

distribution map for Canthon indigaceus

distribution map for Canthon indigaceus