Scaphisoma infinitum, Groll, 2025

Scaphisoma infinitum sp. nov.

urn:lsid:zoobank.org:act:5AC7D322-BA4B-4282-A157-B8B772D51C4B

Figs 1A–D View Fig , 50–54 View Fig View Fig View Fig View Fig View Fig , 93F–J View Fig

Diagnosis

Body length: 1.09–1.36 mm. Brown to dark brown. Very shining, lacking microsculpture. Antennomere IX elongate. Submesocoxal lines slightly arcuate and punctate. Basal stria absent; sutural striae curved anteriorly. Aedeagus distinctly small; apical elongate and triangular; sclerite of internal sac simple. Distal gonocoxite in females elongate.

Etymology

The species epithet is a Latin word meaning ‘endless’, due to the large number of beetles that have been collected.

Material examined

Holotype

BRAZIL • ♂; Minas Gerais, Viçosa, Mata da Biologia ; 23 Nov. 2021; E. von Groll and G.L.N. Martins leg.; “/ Em fungo branco ressupinado no tronco caído / HOLOTYPUS ♂ ”; CELC. ( Fig. 50D–E View Fig ) Paratypes

BRAZIL • 3 ♂♂, 3 ex. (1 ♂ *); same collection data as for holotype; EPTEA Mata do Paraíso ; 12 Nov. 2019; LabCol leg.; “Fungo 02 / Em fungo branco ressupinado em tronco indet.”; CELC • 2 ♂♂, 4 ♀♀, 2 ex. (1 ♀ *); same collection data as for holotype; EPTEA Mata do Paraíso ; 12 Nov. 2019; LabCol leg.; “Fungo 10 / Em Ceratiomyxa fruticulosa ”; CELC • 12 ♂♂, 8 ♀♀, 2 ex. (1 ♂ *, 1 ♂ **, 2 ♀♀ **); same collection data as for holotype; 13 Nov. 2019; E. von Groll et al. leg.; “Fungo 16 / Em fungo amarelado ressupinado em tronco caído indet.”; CELC • 25 ♂♂, 18 ♀♀, 12 ex. (5 ♂♂ **, 1 ♀ **); same collection data as for holotype; EPTEA Mata do Paraíso ; 14 Nov. 2019; LabCol leg.; “Fungo 07 / Em fungo branco ressupinado em tronco indet.”; CELC • 3 ♂♂, 1 ♀, 1 ex. (1 ♂ *); same collection data as for holotype; EPTEA Mata do Paraíso ; 14. Nov. 2019; LabCol leg.; “Fungo 13 / Em fungo ressupinado indet. no tronco caído e em Ceratiomyxa fruticulosa no solo”; CELC • 8 ♂♂, 17 ♀♀, 3 ex. (2 ♂♂ **, 2 ♀♀ **); same collection data as for holotype; EPTEA Mata do Paraíso ; 14. Nov. 2019; LabCol leg.; “Fungo 23 / Em fungo branco ressupinado em tronco indet.”; CELC • 2 ♂♂, 3 ♀♀, 2 ex. (1 ♂ *); same collection data as for holotype; 20 Nov. 2019; E. von Groll et al. leg.; “Fungo 31 / Em fungo amarelado ressupinado em tronco caído indet.”; CELC • 9 ♂♂, 4 ♀♀, 3 ex. (1 ♂ *); same collection data as for holotype; 20 Nov. 2019; E. von Groll et al. leg.; “Fungo 20 / Em fungo branco ressupinado em tronco indet.”; CELC • 3 ♂♂, 4 ♀♀, 3 ex. (1 ♂ *); same collection data as for holotype; EPTEA Mata do Paraíso ; 26 Nov. 2019; LabCol leg.; “Fungo 27 / Em fungo branco ressupinado em tronco indet.”; CELC • 17 ♂♂, 10 ♀♀, 13 ex. (1 ♂ *, 1 ♀ *, 1 ♂ **); same collection data as for holotype; 23 Nov. 2021; E. von Groll and G.L.N. Martins leg.; “/ Em fungo branco ressupinado no tronco caído”; CELC .

Description

COLOURATION. Dark brown. Antennae, mouthparts, legs, tip of elytra, and abdominal ventrites II–VI yellow ( Fig. 50A–B, H View Fig ). Variations: (1) light brown ( Fig. 50F View Fig ); (2) medium brown; (3) pronotum darker than elytra ( Fig. 50G View Fig ).

HEAD ( Figs 50H–J View Fig , 51A–E View Fig ). Punctation fine, sparse; pubescence sparse ( Fig. 50H View Fig ). Labrum conspicuously concave posteriorly ( Fig. 51A View Fig ). Last maxillary palpomere elongate, about 6 × as long as wide ( Fig. 51D View Fig ). Last labial palpomere strongly curved; posterior-lateral sides of mentum concave ( Fig. 51E View Fig ). Antennomeres VIII–XI elongate; antennomere proportions (n =3): I 83/40: II 70/36: III 23/17: IV 48/14:V 72/18: VI 71/21: VII 96/30:VIII 79/21: IX 99/25: X 97/27: XI 124/30.

PROTHORAX ( Fig. 51F–J View Fig ). Pronotum lacking microsculpture; punctures dense and moderately coarse; pubescence fine and short. Hypomeron shining, glabrous; posterior angle not extending significantly beyond anapleural line ( Fig. 52B View Fig ). Prosternal process thick ( Fig. 51H View Fig ). Membranous part of profurca almost rounded ( Fig. 51J View Fig ).

MESOTHORAX ( Fig. 51K–N View Fig ). Visible part of scutellum longer than wide ( Fig. 51F View Fig ); scutellar lines rising laterally; tip acute ( Fig. 51K View Fig ). Mesepimeron about 3.70 × as wide as long ( Fig. 51N View Fig ). Mesoventral lines not curved; punctate; secondary lines absent; median lines short, opened ( Fig. 51L View Fig ). Mesoventral process elongate in lateral view ( Fig. 51M View Fig ).

METATHORAX ( Figs 51L–N View Fig , 52A–C View Fig ). Metaventrite smooth, punctures fine and sparse; pubescence moderately long ( Fig. 51N View Fig ). Submesocoxal lines slightly arcuate; punctate; submesocoxal area length about 0.04 mm ( Fig. 51L–N View Fig ). Metendosternite arms straight, forming an acute V-shape (<40°). ( Fig. 52B–C View Fig ).

WINGS ( Figs 50A–C View Fig , 52D–F View Fig ). Elytra not strongly narrowed apically; punctures coarser than pronotum, pubescence sparse and short. Sutural stria curved near base; basal stria absent ( Fig. 51F View Fig ). Lateral stria slightly curving at humeral area ( Fig. 50B View Fig ).

LEGS. Lacking microsculpture ( Figs 52G–L View Fig , 54D–I View Fig ).

ABDOMEN. Lacking microsculpture, smooth, ventrites with very fine punctures, pubescence like metaventrite ( Figs 51N View Fig , 52M View Fig ). Submetacoxal lines arcuate, with sparse punctures; submetacoxal area length = 0.05–0.07 mm ( Fig. 52M View Fig ). Tergite VI with micro- and coarse punctures ( Figs 52N View Fig , 54J View Fig ).

Males Pro- and mesotarsomeres I–III slightly wide, with few tenent setae (except for mesotarsomere I) ( Fig. 52J– L View Fig ). Sternite and tergite VIII lacking microsculpture. Sternite VIII with a small projection ( Fig. 53A View Fig ).

Tergite VIII straight apically ( Fig. 53B View Fig ). Sternite IX elongate and with parallel sides ( Fig. 53C View Fig ). AEDEAGUS ( Fig. 53D–J View Fig ). Very small, hardly visible between terminal tergites and ventrites ( Fig. 53D–E View Fig ). Median lobe with elongate apical lobe and small and membranous basal bult; apical lobe triangular and sclerotized in ventral and dorsal view ( Fig. 53F, J View Fig ). Parameres almost straight, angulate anteriorly, in frontal view ( Fig. 53F View Fig ). Internal sac membraneous, completely filling median lobe ( Fig. 53G, I View Fig ).

MEASUREMENTS (n= 5, including holotype, unless otherwise specified; in mm). TL (n=35) 1.09–1.31 (1.21 ± 0.06), SY 0.15–0.18 (0.16± 0.01), HW 0.36–0.44 (0.41 ± 0.03), IS 0.17–0.23 (0.19 ± 0.02), WA 0.11–0.14 (0.12 ± 0.01), PL 0.44–0.53 (0.47± 0.03), PA 0.44–0.51 (0.46 ± 0.03), PB 0.68–0.80 (0.76 ± 0.05), EI 0.71–0.84 (0.78± 0.05), EL 0.78–0.95 (0.86 ± 0.07), EW 0.36–0.44 (0.41± 0.03), EH 0.29–0.35 (0.32 ±0.02), Me 0.19–0.22 (0.20 ± 0.02), MeL 0.09–0.12 (0.11 ± 0.01), MeW 0.02–0.03 (0.02 ± 0), MB 0.12–0.15 (0.13 ± 0.01), MC 0.27–0.35 (0.31± 0.04), ML 0.03–0.05 (0.04± 0.01), MA 0.06–0.07 (0.06± 0.01), MA2 0.12–0.17 (0.14± 0.02), VL2 0.19–0.26 (0.22 ± 0.03), VL 0.22–0.29 (0.26 ± 0.03), PrF 0.28–0.35 (0.32 ± 0.03), PrT 0.22–0.27 (0.24 ± 0.02), MsF 0.30–0.36 (0.33± 0.03), MsT 0.27–0.36 (0.30 ±0.04), MtF 0.33–0.42 (0.37± 0.04), MtT 0.33–0.42 (0.37± 0.04).

Females ( Fig. 54 View Fig )

Sternite VIII with a small posterior projection ( Fig. 54K View Fig ). Tergite VIII slightly concave posteriorly ( Fig. 54L View Fig ). Distal gonocoxite slender, curved; gonostylus small, rectangular ( Fig. 54M–N View Fig ).

MEASUREMENTS (n =8; unless otherwise specified; in mm). TL (n =34) 1.17–1.36 (1.26± 0.05), SY 0.16– 0.18 (0.16 ± 0.01), HW 0.40–0.43 (0.41 ±0.01), IS 0.19–0.21 (0.20± 0.01), WA 0.11–0.15 (0.12 ± 0.01), PL 0.46–0.56 (0.50± 0.04), PA 0.40–0.51 (0.46± 0.04), PB 0.70–0.83 (0.76 ± 0.04), EI 0.75–0.89 (0.82 ± 0.05), EL 0.84–0.96 (0.89 ± 0.05), EW 0.41–0.45 (0.44 ±0.02), EH 0.31–0.34 (0.33± 0.01), Me 0.18–0.23 (0.21 ± 0.02), MeL 0.09–0.11 (0.10 ± 0.01), MeW 0.02–0.03 (0.02± 0), MB 0.11–0.16 (0.13 ± 0.02), MC 0.29–0.36 (0.32 ± 0.03), ML 0.03–0.05 (0.04 ± 0.01), MA 0.05–0.07 (0.06 ± 0.01), MA2 0.12–0.16 (0.15± 0.01), VL 0.22–0.26 (0.24 ± 0.02), VL2 0.25–0.29 (0.27± 0.01), PrF 0.31–0.35 (0.33± 0.01), PrT 0.21–0.25 (0.23± 0.01), MsF 0.32–0.36 (0.34 ± 0.02), MsT: 0.28–0.32 (0.30 ± 0.01), MtF (n=7): 0.35–0.42 (0.39 ± 0.02), MtT (n= 7): 0.35–0.42 (0.39 ± 0.02).

Host

Collected from undetermined resupinate and/or crust fungi ( Fig. 93F–J View Fig ). Few specimens collected from a small decomposing log with Ceratiomyxa fruticulosa .

Remarks

Species similar to S. minutipenis Löbl & Ogawa, 2016 due to colour pattern, elongate sternite IX, small aedeagus, and the internal sac lacking sclerite and flagellum. However, it can be easily distinguished by the smaller body length, the slender antennomeres, the more arcuate submetacoxal lines, the longer submetacoxal area, and the absence of ventral abdominal microsculpture.

Distribution

Mata do Paraíso and Mata da Biologia, Universidade Federal de Viçosa, campus of Viçosa, state of Minas Gerais, Southeast Brazil ( Fig. 1A–D View Fig ).