Euglyptus robertensis Byeon & Chandler, 2025

Byeon, Ui-Joung, Chandler, Donald S., Leschen, Richard A. B. & Park, Jong-Seok, 2025, Revision of the New Zealand genus Euglyptus (Coleoptera: Staphylinidae: Pselaphinae) with eight new species, Acta Entomologica Musei Nationalis Pragae 65 (1), pp. 31-59 : 52-54

Euglyptus robertensis Byeon & Chandler , sp. nov.

( Figs 13 , 16 )

Type material. HOLOTYPE: J (genitalia dissected), “ NEW ZEALAND: BR, Nelson Lks.N.P., n slope Mt. Robert, Pinchgut Track 1290m, 18-26. xii.1984 Noth. sol. elfin for. A.Newton / M.Thayer 716 // flight intercept (window) trap” ( NZAC, NZAC04261274 ) . PARATYPEs: NEW ZEALAND: SOUTH ISLAND: BR [Buller]: Nelson Lks.N.P., n slope Mt. Robert, Pinchgut Track 950m, 14.xii.84-6.i.85 Nothofagus spp. forest A.Newton/M.Thayer 707 // flight intercept (window) trap (1 J slide mounted, 1 J genitalia dissected; FMNH). Nelson Lks.N.P., n slope Mt. Robert, Pinchgut Track 1290m, 18-26.xii.1984 Noth. sol. elfin for. A.Newton/M.Thayer 716 // flight intercept (window) trap (1 J genitalia dissected, 1 J; FMNH). Same locality // carrion trap (squid) (1 J slide mounted; FMNH). Nelson Lakes NP, N slope Mt. Robert 860m 23-26. iii.80 Nothofagus spp.A .Newton/M.Thayer // berl, leaf & log litter, forest floor (1 J genitalia dissected, 2 JJ; FMNH). NN [ Nelson]: Slaters Road, 0.7km s Whangamoa Saddle, 410m 13.xii.1984 - 4.i.1985 Nothofagus spp forest A.Newton/M.Thayer 703 // flight intercept (window) trap (1 J genitalia dissected; DSC)

Diagnosis. Males of this species can be distinguished from other Euglyptus species by the following combination of characters: body 1.30–1.34 mm (forebody 0.96–0.98 mm) ( Fig. 13A ); antennomere X wider than long, widest at apex, wider than XI ( Fig. 13C ); pronotum gradually widening from anterior margin to middle, widest in middle, gradually narrowing from middle to posterior margin, with shallow median longitudinal sulcus and broad transverse antebasal sulcus ( Fig. 13B ); abdominal tergite V with short discal striae ( Fig. 13D ); both parameres similar in length, elongate, left paramere slightly curved medially in ventral view, right paramere apex bifurcate in ventral view, left paramere simple, curved ventrally at apex in lateral view; median lobe longer than parameres, evenly curved dorsally, simple ( Figs 13E–J ).

Description. Body 1.30–1.34 mm (forebody 0.96–0.98 mm); head and thorax impunctate; head, thorax, elytra, abdomen, and antennal scape reddish-brown; leg, antennal pedicel, and antennomeres III–IX lighter; tarsus, maxillary palpus, and antennomeres IX–XI yellowish-brown ( Fig. 13A ).

Head as wide as long, with small dorsal tentorial pits, impression weakly defined around dorsal tentorial pits; temples gradually narrowing toward posterior margin of head capsule, with several setae; impression between antennal tubercles narrow, width of impression approximately 0.6 times as wide as antennal tubercle diameter. Pedicel wider than antennomeres III–VIII, antennomeres III longer than wide, IV as long as wide, V longer than wide, VI–VIII as long as wide, IX as long as wide, subhexagonal, X wider than long, widest at apex, wider than XI ( Figs 13A, C ).

Pronotum as wide as head, slightly longer than wide, narrowest at apex, gradually widening from anterior margin to middle, widest in middle, gradually narrowing from middle to posterior margin, with shallow median longitudinal sulcus and broad transverse antebasal sulcus ( Fig. 13B ).

Elytra without any distinguishing characters ( Fig. 13A ).

Abdominal tergite V with short, shallow discal striae ( Fig. 13D ; arrow).

Male genitalia. Both parameres similar in length, elongate, left paramere slightly curved medially in ventral view, with small hook at apex in lateral view; right paramere apex bifurcate in ventral view; median lobe longer than parameres, broadly and evenly curved dorsally to narrowly rounded apex ( Figs 13E–J ).

Etymology. The specific epithet is a Latinised adjective based on the type locality, Mt. Robert.

Distribution. New Zealand (South Island: BR, NN; Fig. 16C ).

Euglyptus sublaevis Broun, 1921

( Figs 14 , 16 )

Euglyptus sublaevis Broun, 1921: 603 . Type locality: Lake Rotoiti,

Nelson.

Euglyptus sublaevis : NOMURA & LEsCHEN (2006: 247).

Type material. HOLOTYPE: J, “4167. / Rotoiti. 5.5.1916 / New Zealand [with red underline] Broun Coll. Brit. Mus. 1922-482. / Euglyptus sublaevis . / [white label] HOLOTYPE Euglyptus sublaevis Broun det. DSChandler” ( BMNH, NHMUK015534122 ).

Additional material examined. New Zealand, South Island: NN [ Nelson]: Lks. NP, St.Arnaud Tr., L.Rotoiti 610-650m 24-26.iii.80 Nothofagus spp.A .Newton,M.Thayer // flight intercept (window) trap (1 J; FMNH).

Diagnosis. Males of this species can be distinguished from other Euglyptus species by the following combination of characters: body 1.86 mm (forebody 1.29 mm), head punctate, thorax impunctate ( Fig. 14A ); antennomere X wider than XI, widening to apex ( Fig. 14C ); pronotum slightly wider than head, gradually widening from anterior margin to middle, widest before middle, gradually narrowing from middle to posterior margin, with distinct median longitudinal sulcus and narrow transverse antebasal sulcus ( Fig. 14B ); each elytron with discal stria remote from second inner fovea extending to posterior margin of elytron ( Fig. 14A ); abdominal tergite V with distinct discal striae, distance between discal striae narrower than discal striae of tergite IV ( Fig. 14D ); both parameres dissimilar in length, left paramere evenly and slightly curved medially for apical half, distinctly longer than right paramere, right paramere slender and acutely pointed apex, with long apophysis originating near base, best seen in lateral view; median lobe expanded apically, fan-shaped and curved dorsally ( Figs 14E–J ).

Redescription. Body 1.86 mm (forebody 1.29 mm); head punctate, thorax impunctate; head, thorax, and abdomen darkish brown; elytra, leg, and antenna reddish-brown; tarsus and maxillary palpus yellowish-brown ( Fig. 14A ). Head wider than long, with large and distinct dorsal tentorial pits, strong impression centered on dorsal tentorial pits; temples gradually narrowing toward posterior margin of head capsule, with several setae; distance between antennal tubercles narrower than antennal tubercle diameter. Pedicel longer and wider than antennomeres III–VIII, antennomeres III–VIII as long as wide, subrectangular or subquadrate, IX slightly wider than long, subhexagonal, X wider than XI (11: 9), widening to apex ( Figs 14A, C ).

Pronotum slightly wider than head, slightly longer than wide, narrowest at apex, gradually widening from anterior margin to middle, widest at before middle, slightly narrowing from middle to posterior margin, with distinct median longitudinal sulcus and narrow transverse antebasal sulcus ( Fig. 14B ).

Elytron with discal stria remote from second inner fovea extending to posterior margin ( Fig. 14A ).

Abdominal tergite V with distinct discal striae ( Fig. 14D ).

Male genitalia. Both parameres dissimilar in length, left paramere slightly curved medially in apical half, apex abruptly angulate ventrally at apex in lateral view, distinctly longer than right paramere in ventral view, right paramere slender and with apex acutely pointed, with thin elongate apophysis at basal 1/4, best seen in lateral view; median lobe apically fan-shaped, recurved anteriorly at apex ( Figs 14E–J ).

Distribution. New Zealand (South Island: NN; Fig. 16C ).

Figures

Fig. 13. Euglyptus robertensis sp. nov. A – habitus dorsal view; B – pronotum; C – apical antennomeres; D – abdominal tergites IV–V; E, F – aedeagus ventral view; G, H – aedeagus lateral view; I, J – aedeagus dorsal view. Scale bars: A = 1 mm; B–J = 0.1 mm.

Fig. 16. Collection localities of New Zealand for Euglyptus species.

Fig. 14. Euglyptus sublaevis Broun, 1921. A – habitus dorsal view; B – pronotum; C – apical antennomeres; D – abdominal tergites IV–V; E, F – aedeagus ventral view; G, H – aedeagus lateral view; I, J – aedeagus dorsal view. Scale bars: A = 1 mm; B–J = 0.1 mm.