Euglyptus parvus 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 : 49

Euglyptus parvus Byeon & Chandler , sp. nov.

( Figs 10 , 16 )

Type material. HOLOTYPE: J (genitalia dissected), “ NEW ZEALAND NN Mt Arthur area Flora Saddle 23-III-2011 // sifted moss sample” ( JTN). PARATYPEs. NEW ZEALAND: SOUTH ISLAND: BR [ Buller]: 0.8kmN Bullock Ck nr. Punakaiki 50m 23.iii.80 broadlf-nikau palm-podocp. A.Newton,M.Thayer // berl., leaf & log litter, forest floor (1 J slide mounted; FMNH). MC [Mid Canterbury]: Arthurs Pass 21-Jan-99 // In moss (1 J genitalia dissected; JTN). WD [ Westland]: 1.8km n Punakaiki, 80m 19.xii.1984 - 20.i.1985 hdwd. for. With nikau A.Newton/M.Thayer 718 // flight intercept (window) trap (1 J slide mounted, 2 JJ genitalia dissected; FMNH). 1.5km n Punakaiki, 50m 19.xii.1984 - 20.i.1985 2˚ hdwd.-nikau forest A.Newton/M.Thayer 720 // flight intercept (window) trap (1 J genitalia dissected; FMNH).

Diagnosis. Males of this species can be distinguished from other Euglyptus species by the following combination of characters: body 1.02–1.14 mm (forebody 0.86–0.89 mm) ( Fig. 10A ); antennomere X wider than long, widest at apex, as wide as XI (8: 8) ( Fig. 10C ); pronotum gradually widening from anterior margin to anterior 1/3 of pronotum length, here widest, gradually narrowing from anterior 1/3 to posterior margin, with shallow median longitudinal sulcus and broad transverse antebasal sulcus ( Fig. 10B ); abdominal tergite V with short, shallow discal striae, width between discal striae relatively wide ( Fig. 10D ); parameres strongly curved ventrally, dissimilar in length, left paramere sinuate with apex curved to right in ventral view, right paramere directed ventrally, abruptly narrowing to acutely pointed apex in lateral view; median lobe longer than parameres, trifurcate at base, apex of left apophysis briefly bifurcate, middle and right apophysis simple with sharp apex, right apophysis longest in ventral view ( Figs 10E–J distorted, rotated anterodorsally).

Description. Body 1.02–1.14 mm (forebody 0.86–0.89 mm); head, thorax impunctate; head, thorax, elytra, abdomen, antennal scape, pedicel, antennomeres III–VIII, leg yellowish-brown, tarsus, maxillary palpus, antennomeres IX–XI lighter than yellowish-brown ( Fig. 10A ).

Head slightly longer than wide, with small dorsal tentorial pits, weak impression 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 0.8 times as wide as antennal tubercle diameter. Pedicel wider than antennomeres III–VIII, antennomeres III–V longer than wide, subrectangular, VI–VIII as long as wide, subquadrate, IX as long as wide, subhexagonal, X wider than long, widest at apex, as wide as XI ( Figs 10A, C ).

Pronotum slightly wider than head, slightly longer than wide, narrowest at apex, gradually widening from anterior margin to 1/3 anterior, widest at 1/3 anterior, gradually narrowing from 1/3 anterior to posterior margin, with shallow median longitudinal sulcus and broad transverse antebasal sulcus ( Fig. 10B ).

Elytra without any distinguishing characters ( Fig. 10A ).

Abdominal tergite V with short, shallow discal striae ( Fig. 10D ; arrow).

Male genitalia. Both parameres directed ventrally, dissimilar in length, left paramere sinuate with apex curved to right in ventral view, with apex medially lobed in dorsal view, right paramere directed ventrally, abruptly narrowing to acutely pointed apex in lateral view; median lobe longer than parameres, trifurcate at base, left apophysis apex briefly bifurcate, middle and right apophyses simple with sharp apex, right apophysis longest in ventral view ( Figs 10E–J distorted, rotated anterodorsally).

Etymology. The specific epithet is the Latin adjective parvus (ʻsmallʼ) and refers to the small body size of this species.

Distribution. New Zealand (South Island: BR, MC, NN, WD; Fig. 16A ).

Figures

Fig. 10. Euglyptus parvus 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.