Diochus crispus Huang, Janak & Zhou 2025, sp. nov.
Creators: name: Huang, Tian
name: Janák, Jiří
name: Zhou, Hong-Zhang
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Diochus
Diochus crispus

description: 1. Diochus crispus Huang, Janák & Zhou, sp. nov.
(Figs 1I; 2-1; 2-2; 2-3)
Type locality. Thailand: Chiang Mai.
Type material. Holotype: male, THAILAND: Chiang Mai: 33 km NE Chiang Mai, 500 m, 3. XI. 85, Burckhardt-Löbl (MHNG). Paratypes: THAILAND: 2 males, 1 female, same data as holotype (MHNG); 1 male, Keng So Pa, 23: XII: 1979, de Rougemont (GROG); 1 male, 1 female, Uttaradit, III: 1987, de Rougemont (JJRC, GROG); 1 female, Uttaradit, III. 1987, Rougemont (GROG); 1 male, R. Kok, C. Rai, 12.III.82, Rougemont (GROG); 1 male, 2 females, r. Kok, Chiang Rai, III: 1987, Rougemont (JJRC); 1 female, Ban Sai Yok, 18.I.82, G. de Rougemont (GROG); 1 female, Ban Sai Yok, 9.III.82, Rougemont (GROG); 1 female, Ban Sai Yok, 9: III: 1982, G. de Rougemont (GROG); 1 female, Ban Hua Mo, 12: III: 1982, G. de Rougemont (GROG); 1 male, Chiang Mai, Doi Suthep National Park, Mok Fa waterfall, leaf litter, 8.11.2019, leg. Kleeberg (AKBG); 10 males, 20 females, Chiang Mai, road 118 to Chiang Rai, Mae Lai River, 470 m, 18°54'59''N, 99°14'09''E, 19.II.2017, lg. W. Rossi (VAHG, JJRC); 6 males, 10 females, Doi Inthanon, Mae Ya Waterfall, 18°26'N, 98°36'E, 580 m, along stream, 12.I.2014, leg. Ob (VAHG, JJRC); 2 females, Chiang Mai, Sandoeng, Flussufer [river banks], 350-550 m, Sand [sand], Steine [stones], 12.11.1995, P. Wunderle (PWMG); 1 female, Doi Inthanon, Kew Mae Pan Waterfall, 18°33'N, 98°29'E, 2190 m, sifted, leg. Ob (VAHG); 2 males, 1 female, Doi Inthanon, Muang Ang, 18°32'N, 98°39'E, 500 m, 15.I.2014, along stream, leg. Ob (VAHG); 12 males, 12 females, Doi Suthep, artificial lake, 29.XI.2004, leg. W. Rossi (VAHG, JJRC). Holotype with an identification label: “HOLOTYPUS Diochus crispus sp. nov. Huang, Janák & Zhou det. 2024”. Paratypes with identification labels: “PARATYPUS Diochus crispus sp. nov. Huang, Janák & Zhou det. 2024”, “ PARATYPUS Diochus crispus sp. nov. Janák det. 2017” or “PARATYPUS Diochus crispus sp. nov. Janák det. 2022”.
Measurements. BL = 4.66 mm, FL = 2.20 mm, HL = 0.60 mm, HW = 0.49 mm, EyL = 0.17 mm, TL = 0.34 mm, ANL = 1.23 mm, ANT1 = 0.14 mm, ANT2 = 0.13 mm, ANT3 = 0.13 mm, ANT4 = 0.10 mm, ANT 11 = 0.14 mm, PL = 0.78 mm, PW = 0.71 mm, EL = 0.81 mm, EW = 0.90 mm, SL = 0.61 mm.
Description. Body long, narrowed anteriorly and posteriorly, medium-sized. Body dark brown, abdominal intersegmental membrane lighter. Legs yellowish brown, tarsi distinctly lighter. Antennae brown, apex of each antennomere lighter. Maxillary and labial palpi brown.
Head (Fig 2-1A). Oblong in shape, 1.30 times as long as wide. Tempora slightly widened backwards, posterior angles rounded. Dorsal surface shiny, bearing distinct transverse microstriae, also with coarse and sparse punctures. Head with 5−7 irregular punctures scattered around each eye and with numerous smaller punctures on deflexed portion of temple and near posterior margin. Each side of head with characteristic punctures: one frontal puncture on frontal region, two anterolateral punctures near antennal insertion, three lateral punctures near dorsal margin of eye, with temporal puncture and occipital puncture near basal margin; disc surface bearing two additional paired punctures in middle area. Frontal and anteocular furrows absent. Eye medium-sized, distinctly protruding laterad, longitudinal diameter about half the length of tempora (eye: tempora = 0.50). Epistoma not flattened, abruptly oblique, anterior margin slightly emarginate medially. Distance between antennal insertions (0.13 mm) distinctly longer than distance from antenna to eye (0.06 mm). Ventral surface with scattered punctures, interspaces between them as large as about 4 puncture diameters. Gular sutures deep, gradually convergent, but not confluent, then divergent to neck region.
Antennae (Fig 2-1B). Scape rod-shaped, slightly thickened apically, distinctly shorter than two subsequent antennomeres combined; antennomere 2 slightly elongate, antennomere 3 about the length of 2; length of antennomere 4 about twice of width, antennomere 4 to 10 gradually shortened, antennomere 4 observably longer than 10; antennomere 11 distinctly longer than 10.
Mouthparts (Figs 2-1A). Labrum oval-shaped, lateral margin rounded, widest at basal 1/2; width of anterior margin about 1/2 the width at the widest point. Mandibles (Fig 2-1D) falciform, left one with three small teeth on inner margin, whereas right one with two.
Neck (Fig 2-1A). Cylindrical, shiny, only bearing shallow microsculpture, width 0.15 mm, shorter than 1/3 of head width. Dorsal surface with distinct groove; ventral surface with gular sutures forming obvious triangular region, with deep transverse median furrow.
Prothorax (Figs 2-1A, I). Pronotum slightly elongate (PL to PW ratio 1.09), longer and wider than head. Anterior region near anterior angles deflexed, lateral margins widened posteriad to basal 1/4 (widest at 1/4), then convergent backwards, anterior and posterior angles broadly rounded. Dorsal surface glossy, extensively with micropunctures, but without any microsculpture. Each side of longitudinal midline with one row of punctures composed of 3 large punctures and 2 additional punctures outside of puncture row, 13–15 punctures scattered near each margin (including anterior, lateral and posterior margins). Prosternum bearing an observable transverse ridge between basisternum and furcasternum, angularly backwards.
Pterothorax (Fig 2-1A). Mesoscutellum triangular, surface shiny, bearing distinct microstriae, but without any punctures. Transverse ridge on mesoventrite wave shaped; paired oblique furrows short but deep; carina limiting mesocoxal cavity slightly arcuate. Discrimen region on metaventrite normally elevated.
Elytra (Fig 2-1A). Elytra transverse (EL to EW ratio 0.90), distinctly longer and wider than pronotum. Humeri well developed, lateral margins divergent posteriorly, posterior margin not rounded, but obliquely truncate. Dorsal surface shiny, flattened, without microsculpture; each elytron with row of 5 punctures along suture, row of 5 punctures on disc, also with 4−5 rows of punctures on deflexed portion.
Legs (Fig 2-1C). First four segments of protarsi heart-shaped, moderately dilated, and those of meso- and metatarsi slender. Last segment of protarsi slightly shorter than 2−4 together, that of meso-, meta- slightly shorter than the length of each 2−3.
Abdomen. Broadest at segment V. Tergites III–VII covered with dense and obvious transverse microstriae; each tergite with dense brown pubescence, also with row of darker and coarser setae at posterior margin of III–VI. Tergites III–VII with a basal impression near anterior margin, respectively, each one only possessing one basal transverse carina; all abdominal tergites with surface shiny, bearing polygonal microsculpture, with dense punctures. Posterior margin of tergite VII with distinct palisade fringe. All abdominal sternites shiny, with microstriae and punctures as those on tergites.
Male (Figs 2-1E–J; 2-2A–G; 2-3A–E). Head with small round elevation between eyes. Posterior margin of sternite VIII emarginate medially (Figs 2-1E; 2-2A–C; 2-3B), also emarginate on both sides. Posterior margin of tergite VIII arcuate (Figs 2-1F; 2-3C). Tergite IX (Figs 2-1H; 2-3D) symmetrical, connected mediobasally, narrowed apically. Sternite IX (Figs 2-1G; 2-3E) asymmetrical, widest near basal 1/3; basal margin straight, apical margin normally emarginate; width of apical margin about 1/2 of basal margin. Tergite X (Figs 2-1H; 2-3D) symmetrical, triangular. Aedeagus (Figs 2-1 I−J; 2-2D–G; 2-3A) symmetrical, medium-sized, ca. 0.60 mm long, normally sclerotized. Parameres symmetrical, medium length, reaching to apical fourth to fifth of median lobe. Internal structures sclerotized, composed of four parts: paired rod-shaped sclerites at periphery, in black color; 3 sclerites in middle: paired rectangular sclerites in black color, Y-shaped sclerite in brown color. Sperm pump coiled, thinned toward apex.
Female (Figs 2-2H–K; 2-3F–I). Head without elevation between eyes. Sternite VIII (Fig 2-2F) with posterior margin rounded. Tergite IX bearing numerous setae, elongate and sharply pointed apically. Sternite IX (Fig 2-3H) symmetrical, with deep concaved margin in middle. Tergite X broad, basal margin curved. Sternite X (Fig 2-3G) slender and rhomboidal, with numerous setae in lower half. Tube of spermatheca sclerotized and wavy in middle part, with three bends (Figs 2-2H–K; 2-3I).
Distribution. Thailand.
Diagnosis. This species is similar to D. punctipennis in body size and coloration, but D. punctipennis has more elongate antennomeres. Regarding the body size and short antennomeres, this species is also similar to D. bilobatus sp. nov. and D. bisegmentatus. This species can be separated from them by less dilated first four segments of protarsi, thicker parameres of aedeagus and the shape of male sternite VIII.
Etymology. The name crispus is a Latin word and refers to the wavy shape of the tube of spermatheca.
description: Published as part of Huang, Tian, Janák, Jiří & Zhou, Hong-Zhang, 2025, Revision of the genus Diochus Erichson (Coleoptera: Staphylinidae, Staphylininae, Diochini) from Thailand and Myanmar, pp. 105-142 in Zootaxa 5620 (1) on pages 107-113, DOI: 10.11646/zootaxa.5620.1.5, http://zenodo.org/record/15219019