Balleriodes sphaera, Grebennikov, 2021

Grebennikov, Vasily V., 2021, Phylogenetic placement of a new paleoendemic pill scarab from the Udzungwa Mountains, Tanzania, triggers biogeographic interpretations (Coleoptera: Hybosoridae, Ceratocanthinae), Fragmenta entomologica 53 (2), pp. 283-298 : 290

Balleriodes sphaera sp. nov.

Figs 1B–F , 2A–S , 3 , 4 , 5 )

Type locality. Tanzania, the Udzungwa Mountains , 7.8419º S 36.8546º E, 1083 m .

Description. The morphological description is the same as that given above for the genus. Holotype maximal body length (in enrolled position, Fig. 1B ): 3.2 mm (variation: 3.2 – 3.4, n = 3), maximal body width 3.0 (variation: 3.0 – 3.2 mm, n = 3), maximal body height in lateral view ( Fig. 1D ): 2.6 mm. DNA of holotype: MW393776 (COI); DNA data of paratypes: MW340075, MW340084, MW393773–5, MW393777–9 (COI), MW340105 (ITS2) and MW340120, MW340129 (28S).

Material examined. Holotype (deposited in the Canadi- an National Collection of Insects , Arachnids and Nematodes , Ottawa, Canada), not sexed, “ TANZANIA, Udzungwa Mts., -7.8419 36.8546, 1083m, 7.x.2014, sift03, V.Grebennikov”, “CNCCOLVG00008750” . Paratypes (deposited together with the holotype), eight specimens 8751–55 and 8968–70, same data as holotype (of them specimen 8968 is in the collection of Alberto Ballerio; see Acknowledgements) .

Distribution. This species is known only from the type locality.

Biology. All specimens were taken in a single sifting sample in the montane rainforest, although a total of 13 sifting samples was taken in the Udzungwa Mountains (sample list in Table 1 in Grebennikov 2017). Phoretic mites were detected under the elytra of both dissected paratypes ( Figs 2I, J ).

Etymology. The species epithet is the Latin noun meaning “ball, globe, sphere”, with reference to the peculiarly globular shape of conglobate specimens of the new species, likely most closely approaching a perfect sphere among all Ceratocanthinae (and, therefore, of all Coleoptera ); in apposition.

Figures

Fig. 1 – A, Distribution of Balleriodes sphaera gen. et sp. nov. and potentially related and/or similar pill scarabs in Africa and Madagascar. B-F: Balleriodes sphaera gen. et sp. nov., holotype, habitus (B: left lateral, C: dorsal, D: ventral; E: anterior, F: posterior).

Fig. 2 – Balleriodes sphaera gen. et sp. nov., paratypes (A-R, specimen 8969, S, specimen 8752), details. A-B, head, fronto-dorsal (A) and frontal (B); C, maxilla; D, labrum; E-F, mandibles; G, antenna; H: labium; I-J, elytron in ventral view showing phoretic mites (J, enlarged); K, prothorax, ventral view; L-N, fore, middle and hind left legs; O, pterothorax, ventral view; P-R, phallobase and parameres, right lateral (P), left lateral (Q) and dorsal (R) views; abdomen, with male genitalia in situ. Images are not to scale.

Fig. 3 – Habitus of select ingroup and outgroup pill scarabs, dorsal view; images are to scale.

Fig. 4 – Habitus of select ingroup and outgroup pill scarabs, left lateral view; images are to scale.

Fig. 5 – Maximum likelihood tree of Ceratocanthinae pill scarabs (Coleoptera: Hybosoridae), as reconstructed by RAxML from the three-fragment concatenated matrix.Balleriodes sphaera gen. et sp. nov. is inside the monophyletic Synarmostes group. Branches with ML bootstrap support percentage ≥90 are marked by black circles; those with bootstrap <90 and ≥75 are marked by open rhombi. Colours of Ceratocanthinae taxa and branches indicate their biogeographical region. Habitus images are to scale; small black arrows indicate imaged specimens.