Diochus myanmarensis 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 myanmarensis

description: 6. Diochus myanmarensis Huang, Janák & Zhou, sp. nov.
(Figs 1E; 7-1; 7-2)
Type locality. Myanmar: Shan Prov.: Hsipaw.
Type material. Holotype: male, MYANMAR: Shan Prov.: Hsipaw, ca. 600 m, 22. 02. 96, litter, leg. S. Kurbatov (MHNG). Paratypes: MYANMAR: 3 males, 3 females, same data as holotype (MHNG, JJRC); THAILAND: 1 male, Do Suthep Nature Trail Phalad, 29.XI.2004, W. Rossi (VAHG). Holotype with an identification label: “ HOLOTYPUS Diochus myanmarensis sp. nov. Huang, Janák & Zhou det. 2024”. Paratypes with identification labels: “ PARATYPUS Diochus myanmarensis sp. nov. Huang, Janák & Zhou det. 2024”.
Measurements. BL = 5.19 mm, FL = 2.41 mm, HL = 0.66 mm, HW = 0.54 mm, EyL = 0.20 mm, TL = 0.35 mm, ANL = 1.48 mm, ANT1 = 0.22 mm, ANT2 = 0.14 mm, ANT3 = 0.16 mm, ANT4 = 0.11 mm, ANT 11 = 0.14 mm, PL = 0.86 mm, PW = 0.76 mm, EL = 0.95 mm, EW = 1.01 mm, SL = 0.68 mm.
Description. Body long, narrowed anteriorly and posteriorly, medium-sized. Body blackish brown, abdominal intersegmental membrane lighter.Legs brown, tarsi distinctly lighter.Antennae dark brown, apex of each antennomere lighter. Maxillary and labial palpi brown.
Head (Fig 7-1A). Rounded oblong in shape, 1.22 times as long as wide. Tempora slightly widened backwards, posterior angles rounded. Dorsal surface shiny, bearing distinct and transverse microstriae, also with coarse and sparse punctures. Head with 5−7 irregular punctures scattered around each eye and 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 furrows and anteocular furrows absent. Eye large-sized, distinctly protruding laterad, longitudinal diameter slightly longer than half the length of tempora (eye: tempora = 0.57). Epistoma not flattened, abruptly oblique, anterior margin slightly emarginate medially. Distance between antennal insertions (0.15 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, approaching to each other before base, but not confluent.
Antennae (Fig 7-1B). Scape rod-shaped, slightly thickened apically, distinctly shorter than two subsequent antennomeres combined; antennomere 2 distinctly elongate, antennomere 3 distinctly longer than 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 (Fig 7-1A). Labrum nearly hexagonal, lateral margin straight, widest at basal 1/2; width of anterior margin is about 1/3 the width at the widest point. Mandibles (Fig 7-1D) falciform, left one with three small teeth on inner margin, whereas right one with two.
Neck (Fig 7-1A). Cylindrical, shiny, only bearing shallow microsculpture, width 0.16 mm, distinctly shorter than 1/3 the head width. Dorsal surface with distinct groove; ventral surface with gular sutures forming obvious triangular region, with deep transverse median furrow.
Prothorax (Fig 7-1A). Pronotum elongate (PL to PW ratio 1.12), distinctly 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 observable transverse ridge between basisternum and furcasternum, angularly backwards.
Pterothorax (Fig 7-1A). Mesoscutellum triangular, surface shiny, bearing distinct microstriae, but without any punctures. Transverse ridge on mesoventrite wave shaped; the paired oblique furrows short but deep; carina limiting mesocoxal cavity slightly arcuate. Discrimen region on metaventrite normally elevated.
Elytra (Fig 7-1A). Elytra slightly transverse (EL to EW ratio 0.95), 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, a row of 5 punctures and a row of 4 punctures on disc, also with 4−5 rows of punctures on deflexed portion.
Legs (Fig 7-1C). First four segments of protarsi heart-shaped, dilated, and those of meso- and metatarsi slender. Last segment of protarsi about the length of 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 and 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 7-1I–J; 7-2A–E). Head with small round elevation between eyes. Posterior margin of sternite VIII shallowly emarginate medially, also with emarginations on both sides (Figs 7-1E; 7-2B). Posterior margin of tergite VIII arcuate (Figs 7-1F; 7-2C). Tergite IX (Figs 7-1H; 7-2D) symmetrical, connected mediobasally, narrowed apically. Sternite IX (Figs 7-1G; 7-2E) symmetrical, widest near basal 1/3; basal margin slightly emarginated, apical margin slightly emarginated; width of apical margin about half of basal margin. Tergite X (Figs 7-1H; 7-2D) symmetrical, triangular. Aedeagus (Figs 7-1I−J; 7-2A) symmetrical, medium-sized, ca. 0.61 mm long, normally sclerotized. Parameres symmetrical, thin and long, reaching about apical sixth of median lobe. Internal structures sclerotized with paired brown, triangular sclerites distally; black paired strip-shaped sclerites and black paired rectangular sclerites in middle, and an elongate brown, triangular sclerite basally. Sperm pump coiled, thinned toward apex.
Female (Figs 7-2F−I). Head without elevation between eyes. Sternite VIII with posterior margin rounded (Fig 7-2F). Tergite IX bearing numerous setae, elongate and sharply pointed apically. Sternite IX (Fig 7-2G) symmetrical, with deep concave margin in middle. Tergite X broad, basal margin curved. Sternite X (Fig 7-2G) slender and rhomboidal, with numerous setae in lower half. Tube of spermatheca sclerotized and short, with only one bend (Fig 7-2I).
Distribution. Myanmar.
Diagnosis. The new species is similar to D. guizhouensis and D. conicollis in appearance. However, in this species the head is less elongate, eyes are larger, male aedeagus has distinctly longer parameres, and the posterior margin of male sternite VIII is with distinct and shallower emarginations on both sides, which can distinguish the new species from both other.
Etymology. The species name refers to the type locality.
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 128-132, DOI: 10.11646/zootaxa.5620.1.5, http://zenodo.org/record/15219019