Dung Beetle Scarabaeus (Scarabaeolus) flavicornis
Suborder: Polyphaga. Family: Scarabaeidae. Subfamily: Scarabaeinae. Tribe: Scarabaeini.
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Kgalagadi Transfrontier Park
Genus Scarabaeus
The genus
Scarabaeus consists of a number of Old World dung beetles. Afrotropical species of
Scarabaeus Linnaeus are confined chiefly to the southern part of the continent, but one occurs as far northeast as Somalia (
S. laevifrons Fairmaire) and another extends northwest into Senegal (
S. palemo Olivier). Most species are sculptured and hirsute, due to wide separation of lateral carinae, have the elytral edge more-or-less rounded in profile, and nearly two-thirds possess a vestigial second mesotibial spur. Sexual dimorphism is slight to altogether absent.
Subgenus Scarabaeolus
Scarabaeolus BALTHASAR - species belonging to this subgenus are morphologically characterized by their small size (relative to most Scarabaeini species), a second vestigial mesotibial spur and hunched body, which closely resembles that of
Sceliages. Most are confined to the arid and semi-arid regions of the southern afro-tropics. A few species have a more northerly distribution, such as
S. Scholtzi, a flightless species occurring in coastal Somalia. Many species are opportunistic feeders, partitioning various types of dung as well as carrion in regions where dung is a scarce resource. Some species have been observed feeding on carcasses of millipedes and
P. femoralis.
The number of recorded species of this subgenus is 41 (March 30, 2018)*, most of them show a regionally restricted distribution pattern centred on southern and southern central Africa. Furthermore, one observation of a
Scarabaeus (Scarabaeolus) bohemani female following a male rolling a ball suggests that members of the subgenus may also show behavioral differences to
Scarabaeus (Scarabaeus) species in which the female clings to the side of a ball being rolled by the male.
Description Scarabaeus (Scarabaeolus) flavicornis
Length 11-19 mm. Habitus black. Elytra flat, not prominently striated. Antennae orange. It possesses 2 mesotibial spurs.
Zídek, Jiri and Pokorny, Svatopluk, "New species of the Scarabaeus subgenus Scarabaeolus Balthasar, with a review of the subgenus
(Scarabaeidae: Scarabaeinae: Scarabaeini)" (2018). Insecta Mundi. 1137.
Distribution
Namibia (Damaraland, Swakopmund), s. Angola, Botswana, South Africa (North West & Northern Cape), Zambia.
Scarabaeus (Scarabaeolus) flavicornis occurs from Lamberts Bay [32° 5’S 18°19’E] in the south (South Africa) to Liuwa plains [14°38’S 22°37’E] in the north (Zambia).
Habitat
Arid and semi-arid regions, deep Kalahari sands.
Biology
Nocturnal telecoprid (ball-rolling) dung beetle. The activity of
S. flavicornis is much longer in summer than during the other seasons, starting after sunset at 20:00 and continuing through the night, ceasing just before sunrise at 5:00. By having nocturnal activity it can successfully avoid direct competition with larger species such as
Pachylomenls femoralis. Nocturnal dung beetles can raise and regulate their body temperature by endothermic means just before and during flight, but thoracic warm-up is particularly expensive in energetic terms for small beetles because of radiant heat loss. That's why
S. flavicornis is less active during spring and autumn, in cold conditions the activity generally starts later and ceases earlier.
Links:
*
https://digitalcommons.unl.edu/cgi/view ... sectamundi
https://repository.up.ac.za/bitstream/h ... sAllowed=y
https://www.inaturalist.org/taxa/549131 ... wse_photos
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