Diochus punctipennis ( Motschulsky, 1858 ), 2004

Huang, Tian, Janák, Jiří & Zhou, Hong-Zhang, 2024, Six new species and a key to 12 species of the genus Diochus Erichson (Coleoptera: Staphylinidae, Staphylininae, Diochini) from India, Nepal and Pakistan, Zootaxa 5538 (6), pp. 501-545 : 532-535

9. Diochus punctipennis ( Motschulsky, 1858)

( Figs 1H ; 10-1; 10-2)

Rhegmatocerus punctipennis Motschulsky, 1858: 659 (Type locality: Indes orientales).

Diochus punctipennis ; Fauvel, 1898: 117 ( Seychelles); Kolbe, 1910: 20 ( Seychelles); Bernhauer and Schubert, 1914: 319 (catalog); Bernhauer, 1922: 176 ( Seychelles); Cameron, 1932: 46 (characters; India); Scheerpeltz, 1933: 1324 (catalog); Cameron, 1934: 79 (type examined); Cameron, 1937: 4 (Java); Scheerpeltz, 1957: 233 (Sumba); Coiffait, 1981: 329 (Andaman Islands); Lecoq, 1990: 189 (Mascarene Islands).

Type material (examined). One of us (JJ) examined one female specimen from Motschulskyʼs collection ( ZMM) , dissected and remounted by Arnaldo Bordoni (Figs 10-2A-C; F; H). The spermatheca was broken and embedded in unnatural position (Fig. 10-2B); a reconstructed original position is as in Fig 10-2C. Motschulsky (1858) did not mention the number of specimens, thus we consider this specimen as a syntype. The specimen was here designated as a lectotype to stabilize the status of the species and is labelled as follows: small rounded yellow label, “Ind.or.” (white, Motschulskyʼs handwriting), “ Rhegmatocerus punctipennis Mots. Ind. or.” (yellow, Motschulskyʼs handwriting), “ Diochus punctipennis Mot. Det. BORDONI 2004 ” (printed and with Bordoniʼs handwriting), “LECTOTYPUS Rhegmatocerus punctipennis Motschulsky, J. Janák des. 2022”, “ Diochus punctipennis (Motschulsky) , J. Janák det. 2022” (ZMM) .

Additional material examined. THAILAND: 3 males, 1 female, Thailand, Ban Sai Yok , 9.III.82, G. de Rougemont ( GROC, JJRC) ; 2 females, Thailand, Khao Yai N.P. , Haew Narok Falls , 19.XI.2004, leg. W. Rossi ( VAHC, JJRC) ; 1 female, Ko Chang NP , 10.12.90, leg. Forster ( NHMW) . MALAYSIA: 2 males, 1 female, The Gap , Selangor, F. M. S., Dr. Cameron ( NHMUK, JJRC) .

Measurements. BL = 4.00 mm, FL = 2.28 mm, HL = 0.63 mm, HW = 0.51 mm, EyL = 0.18 mm, TL = 0.36 mm, ANL = 1.33 mm, ANT1 = 0.22 mm, ANT2 = 0.12 mm, ANT3 = 0.14 mm, ANT4 = 0.11 mm, ANT 11 = 0.15 mm, PL = 0.86 mm, PW = 0.66 mm, EL = 0.82 mm, EW = 0.86 mm, SL = 0.64 mm.

Description. Body long, narrowed anteriorly and posteriorly, medium-sized. Body dark brown, posterior parts of abdominal segments lighter, reddish brown, intersegmental membrane reddish yellow. Legs yellowish brown. Antennae brown with first 1–3 antennomeres and apex of each antennomere lighter, light reddish brown. Maxillary and labial palpi yellowish brown.

Head (Figs 10-1A; 10-2A). Oblong in shape, 1.25 times as long as wide. Tempora almost straight and almost 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 tempus and near posterior margin. Each side of cranium 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, slightly protruding laterad, longitudinal diameter about as long as half the length of tempora (eye: tempora = 0.49). Epistoma not flattened, abruptly oblique, anterior margin slightly emarginate medially. Distance between antennal insertions (0.18 mm) distinctly longer than distance from antenna to eye (0.10 mm).

Antennae (Fig 10-1B). Scape rod-shaped, slightly thickened apically, slightly shorter than two subsequent antennomeres combined; antennomere 2 slightly 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 (Figs 10-1A; 10-2A). Labrum nearly hexagonal, lateral margin straight, widest at basal 1/3 to 1/2; width of anterior margin is about 3/5 the width at the widest point.

Neck (Figs 10-1A; 10-2A). 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 10-1A; 10-2A). Pronotum distinctly elongate (PL to PW ratio 1.31), 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, with scattered 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).

Pterothorax (Figs 10-1A; 10-2A). Mesoscutellum triangular, surface shiny, bearing slightly transverse very fine mesh, but without any punctures.

Elytra (Figs 10-1A; 10-2A). Elytra slightly ransverse (EL to EW ratio 0.96), about as long as but 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 6 punctures in median, also with 5−6 rows of punctures on deflexed portion.

Legs (Figs 10-1A; 10-2A). First four segments of protarsi heart-shaped, moderately dilated, and those of meso- and metatarsi slender. Last segment of protarsi slightly longer than 2−4 together, that of meso-, meta- markedly longer than length of each 2−3.

Abdomen. Broadest at segment IV. 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 fine transverse or polygonal mesh, with dense punctures. Posterior margin of tergite VII with distinct palisade fringe.

Male (Figs 10-1A−G). Head with a small oval elevation between eyes. Posterior margin of sternite VIII shallowly emarginate medially (Figs 10-1C−D). Aedeagus (Figs 10-1E−G) symmetrical, medium-sized, ca. 0.68 mm long, normally sclerotized. Parameres symmetrical, thin and long, reaching almost apex of median lobe. Internal structures sclerotized. Paired rod-shaped sclerites at periphery, in black color; 3 sclerites in the middle: paired rectangular sclerites in black color, a Y-shaped sclerite in brown color; a round sclerite in bottom, black color. Sperm pump coiled, thinned toward apex.

Female (Figs 10-2B−E). Head without elevation between eyes. Spermatheca with short, simply bent tube.

Diagnosis. The species is externally very similar to D. cameroni sp. nov. and differs from this and all related species by the shape of male sternite VIII with shallow rounded emargination and spermatheca with short, simply bent tube.

Distribution. Malaysia (Selangor), Thailand. Other published records ( Seychelles, Mauritius, Réunion, Rodriguez, Andaman Is., India) have to be verified.

Figures

FIGURE 1. Habitus of Diochus species from Bhutan, India, Nepal, Myanmar, Pakistan and Thailand in dorsal view: A. D. guizhouensis Shuai, Nozaki & Tang, 2021; B. D. setatus sp. nov.; C. D. setifer sp. nov.; D. D. emarginatus sp. nov.; E. D. cameroni sp. nov.; F. D. ceylonicus sp. nov., 1929; G. D. conicollis (Motschulsky, 1858); H. D. punctipennis (Motschulsky, 1858); I. D. keralanus sp. nov.; J. D. antennatus (Motschulsky, 1858); K. D. bicoloripennis Coiffait, 1981; L. D. ochraceus Cameron, 1926 (Scale bar: 0.5 mm; photos of six new species based on the holotype respectively).