Diochus bilobatus Huang, Janák & Zhou, 2025

2. Diochus bilobatus Huang, Janák & Zhou , sp. nov.

( Figs 1J View FIGURE 1 ; 3-1; 3-2; 3-3 View FIGURE 2-3 )

Type locality. Thailand: Chiang Mai: Doi Inthanon .

Type material. Holotype: male, THAILAND: Chiang Mai: Doi Inthanon , 1650 m, 7. XI. 1985, Burckhardt-Löbl ( MHNG) . Paratypes: THAILAND: 2 males, 6 females, same data as holotype ( MHNG) ; 4 females, Rd to Wab Pang An, 50 km NE Chiang Mai , 900 m, 3. XI. 85, Burckhardt-Löbl ( MHNG) ; 1 female, Mae Nang Kaeo, 54 km NE Chiang Mai , 900 m, 3. XI. 85, Burckhardt-Löbl ( MHNG) ; 1 male, 4 females, Doi Suthep , 1450 m, 4. XI. 1985, Burckhardt-Löbl ( MHNG) ; 3 males, 9 females, Doi Suthep , 1050 m, 5. XI. 1985, Burckhardt-Löbl ( MHNG) ; 2 females, Doi Inthanon , 1250 m, 6. XI. 1985, Burckhardt-Löbl ( MHNG) ; 1 female, Doi Inthanon , 2450 m, 9. XI. 1985, Burckhardt-Löbl ( MHNG) ; 1 female, Doi Angkhang 10 km W Pang , 1500 m, 20. III. 87, P. Schwendinger ( MHNG) ; 10 females, Taksin Maharat N. P. , 1000 m, 9. 2. 1993, P. Schwendinger ( MHNG) ; 1 male, 3 females, Doi Pui , 19.12.1988, 1500m, leg. Trautner & Geigenmüller ( SMNS, JJRC) ; 1 male, C. M. Doi Pui , III: 1987, Rougemont ( GROG) ; 1 male: river near Ban Pong Din, 32 km ENE Chiang Mai , 27.XI.2004, leg. W. Rossi ( VAHG) . INDIA: Meghalaya: 1 male, Khasi Hills, Weiloi , 1700 m, 27. X. 78, Besuchet-Löbl ( MHNG) ; 1 male, Garo Hills, Tura , 700−900 m, 1. XI. 78, Besuchet-Löbl ( MHNG) . MYANMAR: 1 female, Burma, Taunggy , 17: V: 1980, de Rougemont ( GROG) . CHINA: Guangxi: 1 male, 1 female: Guangxi A. R., 13.iv.2013, Ca 2 km S of Longsheng Hot Spring, Pangxie Gou (forested gorge, stream, wet rocks), 25°53.0'N, 110°12.6'E, 370 m, M. Fikáček, J. Hájek, J. Růžička leg., sifting of leaf litter and leaf accumulations along stony stream in evergreen lowland subtropical forest ( NMPC, JJRC) GoogleMaps ; 2 females, Guangxi A. R., 11.iv.2013, ca. 1.5 km SSE of Longsheng Hot Spring, Dashankoe (rotten logs with fungi; bamboo), 25°53.4'N, 110°12.7'E, 395 m, M. Fikáček, J. Hájek, J. Růžička leg. ( NMPC) GoogleMaps ; Yunnan: 4 males, 1 female, 100 km W Kunming , 22.5.- 2.6.1993, Diaolin Nat. Res ., E. Jendek & O. Sausa leg. ( NHMW, JJRC) ; 3 males, 2 females: N-Yunnan Nujiang Lisu Aut. Pr. Gongshan Co. Gaoligong Shan creek valley 17km N Gongshan , 27°54.41'N, 98°39.55'E, 1525-1600 m, 20.VI.05, A. Smetana ( CNC, JJRC) GoogleMaps ; 3 males, 1 female, 4 specimens sex indet.: E slope N Gaoligongshan , N27°46.8' E098°33.1', 12-15.vi.2009, 200-3000m, sifting 1-7, V. Grebennikov ( CNC, JJRC) GoogleMaps ; 5 females: E slope N Gaoligongshan , N27° 47'51.7'' E098° 34'56.4'', 01.vi.2010, 2100m, sifting 25, V. Grebennikov ( CNC, JJRC) GoogleMaps ; 3 males, 2 females, mt. N Wuding , mixed forest, 25°36'53''N, 102°18'59''E, 2190 m, 17.VIII.2014, V.Assing ( VAHG, JJRC) GoogleMaps ; 22 males, Yunnan, mt.W Gejiu , mixed forest, 23°24'13''N, 103°07'28''E, 1990 m, 23.VIII.2014, V. Assing ( VAHG, JJRC) GoogleMaps ; 1 male, Baoshan Pref., Gaoligong Shan, nr. Xiaoheishan, N.R. , 35 km SE Tengchong , 2110m, 24°50'16''N, 98°45'43''E, decid. Forest, litter, sifted, 4.VI.2007, M. Schülke ( MSBG) GoogleMaps ; 2 females, Nujiang Lisu Aut. Pref., Gongshang Co., Gaoligong Shan, small creek valley, 17 km N Gongshan , 27°54'41''N, 98°39'55''E, 1525-1600 m, along creek under stones / gravel / leaf litter, sifted. 20.VI.2005, M. Schülke ( MSBG) GoogleMaps ; 2 males, 2 females, Nujiang Lisu Aut. Pref., Salween side valley, 5 km S Fugong, road SS 228, km 223 (creek bank, litter sifted), 8.VI.2007 D.W. Wrase ( MSBG, JJRC) ; 1 male, 5 females, Lincang Pref. Bang-Ma Shan, 33 km SSW Lingcang , 2150 m, 23° 35' 41''N, 100°00'27''E, decid. forest remnant, N-slope, litter and dead wood sifted, 11.IX.2009, M. Schülke ( MSBG, JJRC) GoogleMaps ; 1 female, Baoshan Pref., mout. range 14 km E Tengchong , 1850 m (second. mixed forest), field edge, litter, debris sifted), 1.VI.2007, D.W.Wrase ( MSBG) ; 3 males, 1 female, same data, but M. Schülke ( MSBG, JJRC) ; 1 female, Baoshan Pref., moutain range 25 km S Tengchong ,, 1900 m, 24°48'28''N, 98°32'03''E, dev. Primary decid. Forest, litter, fungi sifted, 2.VI.2007, M. Schülke ( MSBC) GoogleMaps ; 2 males, 2 females, Baoshan Pref., Gaoligong Shan, E pass, 78 km N Tengchong , 2000m (cleft with creek and forest remnant, litter/soil sifted), 24°44'49''N, 98°33'29''E, 1.IX.2009, D. W. Wrase ( MSBG) GoogleMaps ; 2 males, 1 female, Baoshan Pref., Gaoligong Shan, E pass, 65 km NNE Tengchong , 1750 m (sec. mixed forest overgrown stone debris, litter and moss sifted), 25°35'20''N, 98°40'21''E, 27.VIII.2009, D. W. Wrase ( MSBG, JJRC) GoogleMaps ; 6 males, 3 females, Baoshan Pref., Gaoligong Shan, E pass, 65 km NNE Tengchong , 1750 m, 25°35'20''N, 98°40'21''E, sec. mixed forest overgrown stone debris, litter and moss sifted, 27.VIII.2009, leg. M. Schülke ( MSBG) GoogleMaps ; 1 male, Baoshan Pref., Gaoligong Shan, W pass, 32 km SE Tengchong , 1600 m, 24°51'11''N, 94°44'28''E, cleft with devast. Primary forest, litter & mush. sifted, 28.VIII.2009, leg. M. Schülke ( MSBG) GoogleMaps ; 1 male, Baoshan Pref., Gaoligong Shan, mount range 25 km S Tengchong , 1900 m, 24°48'21''N, 98°32'05''E, cleft with devast. Primary forest, litter & mush. sifted, 30.VIII.2009, leg. M. Schülke ( MSBG) GoogleMaps ; 12 males, 12 females, Baoshan Pref., Gaoligong Shan, E pass, 65 km NNE Tengchong , 1750 m, 25°35'20''N, 98°40'21''E, sec. mixed forest overgrown stone debris, litter and moss sifted, 31.VIII.2009, leg. M. Schülke ( MSBG, JJRC) GoogleMaps ; 8 males, 12 females, mountain W Gejiu , 23°24'13''N, 103°07'28''E, 1990 m, misted forest, litter and various debris sifted, 24.VIII.2014, leg. M. Schülke ( MSBG, JJRC) GoogleMaps ; 1 male, Baoshan Pref., Gaoligong Shan, 10 km SE Kambaiti pass, 45 km NW Tengchong , 1700-1800 m (river bank under stones), 25°21'13- 29''N / 98°13'39-54''E, 29.VIII.2009, D. W. Wrase ( MSBG) ; 1 male, 1 female, Lincang Pref., Xue Shan, 48 km N Lincang , 2070 m, 24°19'03''N, 100°07'13''E, forest remnant, N slope, litter & mushrooms sifted, 12.IX.2009, leg. M. Schülke ( MSBG) GoogleMaps ; 3 males, 5 females, Dali Bai Aut. Pref., Wuliang Shan, 20 km NW Weishan , 25°19'58''N, 100°07'59''E, 1900m, creek valley, litter & old flood debris sifted, 17.IX.2009, leg. M. Schülke ( MSBG) GoogleMaps ; 1 female, mountain W Yuxi , 24°27'11''N, 102°29'58''E, 2250 m, secondary mixed forest, litter, roots, and moss sifted, 31. VIII.2014, Schülke ( MSBG) GoogleMaps ; 1 female, E Kunming, Xiaobailong Forest Park , 2110 m, 24°55'43''N, 103°05'22''E, sec. pine forest margin, litter sifted. 10.VIII.2014, Schülke ( MSBG) GoogleMaps ; 1 female, Baoshan Pref., Gaoligong Shan, E pass, 36 km SE Tengchong , 24°49'32''N, 98°46'06''E, 2200 m (prim. decid. forest, brook bank, litter, moss, sifted), 31.V.2007, D. W. Wrase ( MSBG) GoogleMaps . VIETNAM: 1 male, 1 female, N-Vietnam, 1.4 km SW Sa Pa , 22°19'20''N, 103°50'04''E, 1170 m, stream valley, 28.VII.2013, V. Assing ( VAHG) GoogleMaps ; 3 females, N-Vietnam, 7 km NW Sa Pa , 22°21'49''N, 103°46'49''E, 1850 m, stream valley, 1.VIII.2013, V. Assing ( VAHG) GoogleMaps ; 1 male, N-Vietnam, above Sa Pa , 22°20'35''N, 103°50'08''E, 1600 m, alder litter, 4.VIII.2013, V. Assing ( VAHG) GoogleMaps ; 1 female, N-Vietnam, pass 8 km NW Sa Pa , 22°21'10''N, 103°46'01''E, 2010 m, secondary forest, 5.VIII.2013, V. Assing ( VAHG) GoogleMaps ; 14 males, 15 females, N-Vietnam, 6 km NW Sa Pa , 22°21'39''N, 103°47'19''E, 1810 m, pasture margin, 7.VIII.2013, V. Assing ( VAHG, JJRC) GoogleMaps ; 15 males, 15 females, N-Vietnam, 10 km NW Sa Pa , 22°22'26''N, 103°45'27''E, 1810 m, stream valley, 8.VIII.2013, V. Assing ( VAHG, JJRC) GoogleMaps ; 2 females, N-Vietnam, pass 8 km NW Sa Pa , 22°21'13''N, 103°46'01''E, 2030 m, forest margin, 9.VIII.2013, V. Assing ( VAHG) GoogleMaps ; 1 female, N-Vietnam, pass 8 km NW Sa Pa , 22°21'13''N, 103°46'01''E, 2030 m, forest margin, 10.VIII.2013, V. Assing ( VAHG) GoogleMaps ; 2 males, 2 females, NVietnam, 7 km NW Sa Pa , 22°21'49''N, 103°46'49''E, 1840 m, stream valley, 1. VIII. 2013, Assing ( VAHG) GoogleMaps ; 2 females, N-Vietnam, 7 km NW Sa Pa , 22°21'49''N, 103°46'49''E, 1840 m, stream valley, 30.VII.2013, Wunderle ( PWMG) GoogleMaps . LAOS: 2 males, 1 female: Houa Phan prov., Phu Phan Mt. 20°12'N, 104°01'E, ca. 1750 m, 17.V.- 3.VI.2007, leg. Vit Kuban ( VAHG, JJRC) GoogleMaps ; 1 male: Hua Pan pr. Ban Saluei, 1300-2000m, 20°13'N, 103°59'E, Phu Phan mts. , 6.-18.v.2004, leg. F. & I. Kantner ( MSBG) GoogleMaps . Others: 1 male, Arunachal Pradesh, Miri hills, Road from Ziro to Daporijo , 29.v.2006, G. de Rougemont leg. ( GROG) ; 1 male, 1 female, Arunachal Pradesh, Napoli , 27.v.2006, G. de Rougemont leg. ( GROG) . Holotype with an identification label: “ HOLOTYPUS Diochus bilobatus sp. nov. Huang, Janák & Zhou det. 2024”. Paratypes with identification labels: “ PARATYPUS Diochus bilobatus sp. nov. Huang, Janák & Zhou det. 2024”, “ PARATYPUS Diochus bilobatus sp. nov. Janák det. 2017” or “ PARATYPUS Diochus bilobatus sp. nov. Janák det. 2022”.

Measurements. BL = 4.59 mm, FL = 2.01 mm, HL = 0.64 mm, HW = 0.47 mm, EyL = 0.15 mm, TL = 0.34 mm, ANL = 1.32 mm, ANT1 = 0.21 mm, ANT2 = 0.12 mm, ANT3 = 0.13 mm, ANT4 = 0.10 mm, ANT 11 = 0.12 mm, PL = 0.72 mm, PW = 0.68 mm, EL = 0.78 mm, EW = 0.83 mm, SL = 0.55 mm.

Description. Body long, narrowed anteriorly and posteriorly, medium-sized. Body dark brown, abdominal intersegmental membrane lighter. Legs yellowish brown to dark brown, tarsi distinctly lighter. Antennae brown, apex of each antennomere lighter. Maxillary and labial palpi brown.

Head ( Fig 3-1A View FIGURE 2-3 ). Oblong in shape, 1.36 times as long as wide. Tempora straight and parallel, 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 medium-sized, distinctly protruding laterad, longitudinal diameter slightly shorter than half the length of tempora (eye: tempora = 0.44). Epistoma not flattened, abruptly oblique, anterior margin slightly emarginate medially. Distance between antennal insertions (0.14 mm) distinctly longer than distance from antenna to eye (0.07 mm). Ventral surface with scattered punctures, interspaces between them about 4 puncture diameters. Gular sutures deep, gradually convergent before basal 1/3, but not confluent, then divergent to neck region.

Antennae ( Fig 3-1B View FIGURE 2-3 ). Scape rod-shaped, slightly thickened apically, distinctly shorter than two subsequent antennomeres combined;antennomere2slightly elongate;antennomere3slightly longer than2;length of antennomere 4 about 1.5 times longer than width, antennomere 4 to 10 gradually shortened, antennomere 4 observably longer than 10; antennomere 11 distinctly longer than 10.

Mouthparts ( Fig 3-1A View FIGURE 2-3 ). Labrum hexagonal, lateral margin straight, widest at basal 1/3; width of anterior margin about 1/2 the width at the widest point. Mandibles ( Fig 3-1D View FIGURE 2-3 ) falciform, left one with three teeth, right one with two teeth.

Neck ( Fig 3-1A View FIGURE 2-3 ). Cylindrical, shiny, only bearing shallow microsculpture, width 0.13 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 ( Fig 3-1A View FIGURE 2-3 ). Pronotum slightly elongate (PL to PW ratio 1.07), 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 an observable transverse ridge between basisternum and furcasternum, angularly backwards.

Pterothorax ( Fig 3-1A View FIGURE 2-3 ). 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 3-1A View FIGURE 2-3 ). Elytra brown, slightly transverse (EL to EW ratio 0.94), 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 3-1C View FIGURE 2-3 ). First four segments of protarsi heart-shaped, moderately 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 yellow 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 3-1E–J; 3-2A–I; 3-3A–E View FIGURE 2-3 ). Head with small oval elevation between eyes. Sternite VIII elongate, posterior margin emarginate medially ( Figs 3-1E; 3-2A–D; 3-3B View FIGURE 2-3 ). Posterior margin of tergite VIII arcuate ( Figs 3- 1F; 3-3C View FIGURE 2-3 ). Tergite IX ( Figs 3-1H; 3-3D View FIGURE 2-3 ) symmetrical, connected mediobasally, narrowed apically. Sternite IX ( Figs 3-1G; 3-3E View FIGURE 2-3 ) symmetrical, widest near basal 1/2 to 1/3; basal margin deeply emarginate, apical margin normally emarginate; width of apical margin distinctly shorter than basal margin. Tergite X ( Figs 3-1H; 3-3D View FIGURE 2-3 ) symmetrical, triangular.Aedeagus ( Figs 3-1 View FIGURE 2-3 I−J; 3-2E–I; 3-3A) symmetrical, medium-sized, ca. 0.56 mm long, strongly sclerotized. Parameres symmetrical, thin and long, reaching to apical seventh of median lobe. Internal structures sclerotized, one bilobate sclerite on top ( Fig 3-2I View FIGURE 2-3 ), in brown color; two paired strip-shaped sclerites on both sides, in brown color. Sperm pump coiled, thinned toward apex.

Female ( Figs 3-2J–M; 3-3F–I View FIGURE 2-3 ). Head without elevation between eyes. Sternite VIII ( Fig 3-2F View FIGURE 2-3 ) with posterior margin rounded. Tergite IX bearing numerous setae, elongate and sharply pointed apically. Sternite IX ( Fig 3-3H View FIGURE 2-3 ) symmetrical, with deep concave margin in middle. Tergite X broad, basal margin curved. Sternite X ( Fig 3-3G View FIGURE 2-3 ) slender and rhomboidal, with numerous setae in lower half. Tube of spermatheca thin and long, with a loop apically ( Figs 3-2J–M; 3-3I View FIGURE 2-3 ).

Distribution. Thailand, India, China (Guangxi, Yunnan), Vietnam, Laos.

Diagnosis. Regarding the similar shape of male sternite VIII, similar structure of the male aedeagus and the female spermatheca, the new species is related to D. antennatus and D. bisegmentatus , but can be distinguished by less elongate pronotum and relatively shorter parameres of the male aedeagus. This species possesses an elevation between eyes, which also distinguishes it from D. antennatus .

Etymology. The name of the species is from Greek terms, bi - and lobat- and refers to the bilobate sclerite near the apex of median lobe of aedeagus.