Toxidium scalenum, Groll, 2025

Toxidium scalenum sp. nov.

urn:lsid:zoobank.org:act:94F752A7-DBE6-490C-A3CF-2BEEC58756F0

Figs 1A–B View Fig , 80–82 View Fig View Fig View Fig

Diagnosis

Body length: 1.90 mm. Reddish-brown; legs ochreous. Sutural striae extending from apex to approximately 0.74 of the elytral sutural length. Posterior angle of pronotum not reaching anapleural line. Submesocoxal area and anterior area of metaventrite with strigulate microsculpture. Metanepisternum conspicuously wider next to the masanepisternum. Sclerite on internal sac of aedeagus J-shaped, long side 2.5× as long as short side.

Etymology

The species epithet is the Latin adjective, meaning ‘scalene’, referring to the metanepisternum’s scalene triangular shape.

Material examined

Holotype

BRAZIL • ♂ *; Minas Gerais, Viçosa, EPTEA Mata do Paraíso ; 17 Mar. 2022; E. von Groll et al. leg.; “Falcon 12 / Em Fungo branco ressupinado no tronco caído / Dissecado em 11.nov.2022 / HOLOTYPUS ♂ ”; CELC. ( Fig. 80D–E View Fig )

Description

COLOURATION. Reddish-brown, redder near sutures; shining; posterior area of clypeus, coxae, femora, and tibiae ochreous; antennae, mouthparts, tip of elytra, tarsi, and apex of abdominal ventrites yellow ( Figs 80A–C View Fig , 81A–F View Fig ).

HEAD. Frons with punctures dense and fine – few coarser punctures near frontoclypeal suture; pubescence dense ( Fig. 80F View Fig ).Antennomeres IV–VI distinctly slender ( Fig. 80H View Fig ), proportions: I 114/50: II 106/50: III 72/16: IV 86/13:V 103/11:VI 98/13:VII 117/27: VIII 88/23: IX 116/34: X 114/38:XI 143/46.

PROTHORAX ( Fig. 80A–C, G View Fig ). Somewhat elongate, smooth. Pronotum fine and moderately dense punctate. Lateral carinae dashed, visible in lateral view ( Fig. 80B View Fig ). Hypomeron with punctures very fine and poorly pubescent ( Fig. 80B View Fig ). Posterior angles of pronotum slightly acute, and not reaching anapleural line ( Fig. 80B View Fig ).

MESOTHORAX. Tip of scutellum exposed, slightly longer than wide ( Fig. 80G View Fig ). Mesanepisternum finely punctate; pubescence sparse ( Fig. 80B View Fig ). Mesoventral lines slightly curved, secondary lines straight ( Fig. 81A View Fig ).

METATHORAX.Metaventrite with imbricate microsculpture between submesocoxal lines and metanepisternal suture; almost glabrous and impunctate ( Fig. 81D View Fig ). Submesocoxal lines punctate; submesocoxal area imbricate microsculptured; length: 0.10 mm ( Fig. 81A View Fig ). Metanepisternum triangular; conspicuously wider next to the mesanepisternum, pubescence denser near metanepisternal suture ( Fig. 81A View Fig ).

WINGS. Elytra with coarse punctures – coarser than pronotum –, pubescence moderately dense ( Fig. 80A View Fig ). Sutural striae shortened, extending from apex up to approximately 0.74 of the sutural length ( Fig. 80A View Fig ). Lateral striae impunctate, just slightly curved at humeral region ( Fig. 80B View Fig ).

LEGS ( Fig. 81C–E View Fig ). With imbricate microsculpture.

ABDOMEN. Shining. Ventrite I with micropuncture near submetacoxal bead ( Fig. 81D View Fig ). Propygidium micropunctured ( Fig. 81F View Fig ).

Male Protarsomeres I–III widened, bearing tenent setae ( Fig. 81C View Fig ). Sternite VIII with a posterior triangular projection ( Fig. 81G View Fig ). Tergite IX with ventral struts slightly curved ( Fig. 81H View Fig ). Sternite IX rounded posteriorly ( Fig. 81I View Fig ). Tergite X triangular, angulate posteriorly ( Fig. 81J View Fig ).

AEDEAGUS ( Fig. 82 View Fig ). Poorly sclerotized. Basal bulb and apical lobe similar in length. Apical lobe triangular ( Fig. 82 View Fig ). Parameres sinuous in lateral view ( Fig. 82C View Fig ). Sclerite of internal sac J-shaped, long side 2.5× as long as short side.

MEASUREMENTS (n =1, holotype; in mm). TL 1.90, SY 0.20, HW 0.81, IS 0.33, PL 0.84, PA 0.55, PB 0.98, EI 1.20, EL 1.26, EW 0.52, EH 0.58, MB 0.13, MC 0.16, MeW 0.30, ML 0.10, VL 0.25, VL2 0.37, PrF 0.50, PrT 0.35, MsF 0.56, MsT 0.46, MtF 0.59, MtT 0.55.

Host

Collected from an undetermined crust/resupinate fungus.

Remarks

Similar to T. fleche sp. nov. but differs mainly by the absence of coarse punctures on the metaventrite, the shallower elytral punctures, and by the bended sclerite of the internal sac.

Distribution

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