Stenaptinus stenoderus ( Chaudoir, 1850 )

Fedorenko, D. N., 2021, Stenaptinus (Coleoptera: Carabidae: Brachininae) of Vietnam. Note 2, Russian Entomological Journal 30 (1), pp. 25-42 : 34-35

4. Stenaptinus stenoderus ( Chaudoir, 1850) , sp.bon.

Figs 1 , 11 , 35–42 , 58 , 65 , 96–97, 103–105 .

Chaudoir, 1850: 77 ( Pheropsophus ; ‘Nord de l’Hindostan’); 1876: 18, 41 (‘Présidence du Bengale’). — consularis (part.): Andrewes, 1923: 44; 1924: 56, 116; 1930: 272; Jedlička, 1964: 532; Hrdlička, 2017: 479; Venugopal et Thomas, 2019: 72. — lei Hrdlička, 2019: 82 (Tay Giang, Central Vietnam), syn.n. — snizeki Hrdlička, 2019: 83 (Chiang Dao, Northern Thailand), syn.n. —? kuntzeni Dupuis, 1914: 29 (Kosempo, Taiwan).

MATERIAL. Two female specimens ( MNHN, digital images) in the box with a handwritten label ‘stenoderus / Chaud/ Indes or. boréale/ Ct Boys.’ at its bottom. Of them, the specimen with labels ‘Ex Musaeo/ Chaudoir’ and ‘G. J. Arrow/ vidit 1901’ is certain to be the holotype, and another specimen without head bears the only label ‘Ex Musaeo/ Chaudoir’.

Additional material. 1♀ ( SIEE), Northern India, Uttarakhand State, Haridwar Distr., env. Chilla , Ganges , floodland forest, 29°58´N / 78°12–13´E, h= 330 m, 14–16.IV.2012 (I. Melnik) ; ♂ ( SIEE), same locality, except for 8 km NNE of Ramnagar, Pipaliasot river valley, 29°28.5´N / 79°10´E, h= 420 m, 20.IV.2012 (E. Ivanov) ; ♂ ♀ ( SIEE), N Thailand, Mae Hong Son Province,env. Pai , 19°22´N / 98°30´29´´E, h= 600 m, 27.IV–9.V.2013 (I. Melnik) ; 2♂♂, 2♀♀ ( SIEE), Vietnam, Nghe An Province, 109 km WNW of Vinh, Pu Mat Nature Reserve , 18°57´22´´N / 104°41´05´´E, h= 270 m, 11–25.IV.2018 (A. Abramov) ; ♂ ( ZISP), mountains W of Quy Chau , h= 600 m, 8.III.1962 (O.N. Kabakov) ; 2♀♀ ( ZISP), same data, except for: mountains SW of Quy Chau , h= 400 m, 13.II.1963 ; ♂ ( MSPU), Quang Binh Province, Minh Hoa [=Quy Dat] Distr., env. Yen Hop , Ke Bang National Park , 24– 30.III.1999 (S. Kruskop) ; 5♂♂, 9♀♀ ( SIEE), Quang Nam Province, Nam Giang Distr., Song Thanh National Park , 15°33´48´´N / 107°23´22´´E, h= 1050 m, 23.IV–11.V.2019 (D. Fedorenko) ; 3♀♀ ( ZISP), Thai Nguen Province NW of Tam Dao [Son Zuong] Mt ridge, h= 200–300 m, 23.II.1962 (O.N. Kabakov).

Genitalia examined in eight males and four females.

DIAGNOSIS. An apterous species with elytra lacking humeri and thence much wider apically than basally in most populations. Dorsal pattern ( Figs 96–97, 103–105 ): vertex with black patch large Y-shaped to small pentagonal yet mostly retaining anterior horns; pronotal pale spots separate, small and/or narrow, to large and fused, leaving lateral margins widely black; elytral transverse band not reaching lateral margin, mostly large and indistinctly dentate or edentate. Tergite VII with 9–15 strong and straight apical setae in female, sternite VII varying from asetose to quadrisetose in male. Aedeagus similar to that of S. lissoderus ( Figs 35–42 ), except for its apex blunt and the internal sac with proximal basal bulbs larger.

Slender specimens are very similar to those of S. javanus , except that the elytral transvere median band is wide, slightly dentate, and isolated from lateral margin, and the wings are constantly missing or much reduced in the former.

REDESCRIPTION. Body. BL 10.5–22 mm. Body pattern ( Figs 96–97, 103–105 ): elytra with apical margin not or narrowly pale; femoral apices black (at least laterally), tibiae infuscated laterally in some populations. Head and pronotum glabrous, without or with several individual short setae, yet setigerous punctures imperceptible.

Pronotum subcordate, slightly to indistinctly longer than wide, broadest a third from apex, with sides barely to distinctly sinuate a fifth from base and rounded before; basal angles slightly obtuse to slightly acute, rather sharp to blunt. Base barely wider than apex. Lateral bead and groove entire and very distinct in Vietnamese populations to fine and entire or imperceptible in front of basal angles nearly imperceptible in the other ones.

Elytra similar in shape and proportions in males and females.

Abdomen ( Figs 1 , 11 ): Tergite VII with larger punctures coarse and dense in female, slightly finer and often also sparser and unevenly spaced in males. Sternite VIII with lateral apical setae rather strongly curved in female.

Legs: Profemora tumid in male.

Female genitalia and reproductive tract ( Figs 58 , 65 ) similar to those of S. javanus .

GEOGRAPHIC DISTRIBUTION. As for S. consularis . The fact is worthy of note that Chaudoir [1876] translated ‘Nord de l’Hindostan’ as the original type locality of the species into ‘présidence du Bengale’ and provided two additional records, including ‘Deccan’ meaning Dacca in fact.

HABITATS AND HABITS. This species has forestdwelling habits, being generally confined to 200–600 m altitudes in piedmonts, with three local populations found at 1050–1400 m in Central Vietnam. This species often live syntopically with some other species of the group, such as S. consularis (in the Pu Mat Nature Reserve and the Ke Bang National Park in Vietnam, and also in the environs of Pai, Thailand) or S. agnatus (in the Song Thanh National Park).

COMMENTS. This species is incapable of flight because of constantly apterous condition of the adults. Since flight function lost the elytra has become much more variable in shape than in macropterous species, resulting in wider ranges of the ratios EL/EW and EW/PW (Table).

Another result is that local populations of S. stenoderus tend to be more isolated from one another than in species having full or polymorhic wings and interpopulation variability tends to surpass intrapopulation variability accordingly. Specifically, the elytra seems to be more dilated apically in populations from Indochina than in those from India. In Thailand and northern Vietnam, the adults have the elytra short, with median fascia not seldom narrow and strongly dentate. Black colour on the head and pronotum becomes considerably reduced in size in populations from Nghe An Province. The adults from there have the Y-shaped patch on vertex shortened from behind and transformed into a pentagon, which is somewhat stellate due to the angles slightly projecting, and pronotum pale, except for its base, apex and narrow lateral margins.

The recently described S. lei is distinctive in only having a generally larger body, the pronotum with sides more sinuate in front of base and thence with basal angles rather acute, and the elytral median facia wide and not or only slightly dentate. All these characters have been observed in some other populations of S. stenoderus , therefore S. lei is here considered as a group of southern populations of S. stenoderus in Vietnam.

Stenaptinus stenoderus and S. lissoderus may be more closely related to each other than to S. stenoderus because aedeagi of the former two are more similar in having preapical frontal bulb of the internal sac (vs. having no this bulb in S. consularis ).

Figures

Figs 1–10. Stenaptinus spp., sternite VIII in female: 1 — S. stenoderus; 2 — S. lissoderus; 3, 6 — S. agnatus from Cat Tien; 4 — S. sumatrensis sp.n.; 5 — S. c. consularis; 6 — S. montanus sp.n.; 7 — S. fimbriatus; 8 — S. consularis flaviceps ssp.n.; 9 — S. javanus; 10 — S. marginicollis. Scale bars: 1 mm. Рис. 1–10. Stenaptinus spp., стернит VIII самки: 1 — S. stenoderus; 2 — S. lissoderus; 3, 6 — S. agnatus иЗ Катьена; 4 — S. sumatrensis sp.n.; 5 — S. c. consularis; 6 — S. montanus sp.n.; 7 — S. fimbriatus; 8 — S. consularis flaviceps ssp.n.; 9 — S. javanus; 10 — S. marginicollis. МасШтаб: 1 мм.

Figs 11–20. Stenaptinus spp., tergite VIII in female: 11 — S. stenoderus; 12 — S. lissoderus; 13, 16 — S. agnatus from Cat Tien; 14 — S. sumatrensis sp.n.; 15 — S. c. consularis; 16 — S. montanus sp.n.; 17 — S. fimbriatus; 18 — S. consularis flaviceps ssp.n.; 19 — S. javanus; 20 — S. marginicollis; adr — apical depigmented region; psm — posteromedian sclerotized region. Scale bars: 1 mm. Рис. 11–20. Stenaptinus spp., тергит VIII самки: 11 — S. stenoderus; 12 — S. lissoderus; 13, 16 — S. agnatus иЗ Катьена; 14 — S. sumatrensis sp.n.; 15 — S. c. consularis; 16 — S. montanus sp.n.; 17 — S. fimbriatus; 18 — S. consularis flaviceps ssp.n.; 19 — S. javanus; 20 — S. marginicollis; adr — апикальнаЯ депигментированнаЯ область; psm — постеро-медиальнаЯ склеротиЗациЯ. МасШтаб: 1 мм.

Figs 29–42. Stenaptinus spp., median lobe of aedeagus with everted and inflated internal sac: 29–30 — S. lissoderus; 31–32 — S. c. consularis; 33–34 — S. c. flaviceps ssp.n.; 35–42 — S. stenoderus from Pu Mat (35, 40), Thailand (36–37), Ramnagar env. (38–39) and Song Thanh (41–42); 29, 31, 33, 36, 38, 40, 42 — dorso-apical aspect; 30, 32, 34–35, 37, 39, 41 — left aspect; fb — preapical frontal bulb. Scale bars: 1 mm. Рис. 29–42. Stenaptinus spp., среднЯЯ долЯ Эдеагуса с вывернутым и надутым внутренним меШком: 29–30 — S. lissoderus; 31– 32 — S. c. consularis; 33–34 — S. c. flaviceps ssp.n.; 35–42 — S. stenoderus иЗ Пумата (35, 40), Таиланда (36–37), окр. Рамнагара (38– 39) и СонгтханЯ (41–42); 29, 31, 33, 36, 38, 40, 42 — дорЗо-апикально; 30, 32, 34–35, 37, 39, 41 — слева; fb — предверШинный фронтальный пуЗырь. МасШтаб: 1 мм.

Figs 56–64. Stenaptinus spp., urite IX in female, ventral aspect: 56 — S. sumatrensis sp.n.; 57 — S. consularis flaviceps ssp.n. from Gia Lai Prov.; 58 — S. stenoderus; 59 — S. javanus; 60 — S. c. consularis; 61 — S. agnatus; 62 — S. marginicollis; 63 — S. fimbriatus; 64 — S. lissoderus; bc — bursa copulatrix; rp — spermathecal receptacle; sg — spermathecal gland. Scale bars: 1 mm. Рис. 56–64. Stenaptinus spp., урит IX самки вентрально: 56 — S. sumatrensis sp.n.; 57 — S. consularis flaviceps ssp.n. from Gia Lai Prov.; 58 — S. stenoderus; 59 — S. javanus; 60 — S. c. consularis; 61 — S. agnatus; 62 — S. marginicollis; 63 — S. fimbriatus; 64 — S. lissoderus; bc — копулЯтивнаЯ сумка; rp — семеприемник сперматеки; sg — желеЗа сперматеки. МасШтаб: 1 мм.

Figs 65–70. Stenaptinus spp., female reproductive tract: 65 — S. stenoderus; 66 — S. fimbriatus; 67 — S. javanus; 68 — S. marginicollis; 69 — S. agnatus; 70 — sumatrensis sp.n.; bc — bursa copulatrix; ov — common oviduct; rp — spermathecal receptacle; sc — seminal canal; sg — spermathecal gland. Scale bar: 1 mm. Рис. 65–70. Stenaptinus spp., репродуктивный тракт самки: 65 — S. stenoderus; 66 — S. fimbriatus; 67 — S. javanus; 68 — S. marginicollis; 69 — S. agnatus; 70 — sumatrensis sp.n.; bc — копулЯтивнаЯ сумка; ov — непарный Яйцевод; rp — семеприемник сперматеки; sa — апикальные Щетинки; sс — семенной канал; sg — желеЗа сперматеки. МасШтаб: 1 мм.

Figs 90–105. Stenaptinus spp., variation of dorsal pattern in specimens from different localities: 90–94 — S. consularis; 95 — S. marginicollis; 96–97, 103–105 — S. stenoderus; 98–102 — S. lissoderus; 90–91, 101–102, 104 — Northern Thailand; 92 — Gia Lai Prov.; 93, 96 — Pu Hoat NP; 94 — Ke Go NP; 97 — Tam Dao; 98–100, 103 — India; 105 — Song Thanh NP. Рис. 90–105. Stenaptinus spp., иЗменчивость окраски верха у особей иЗ раЗных местонахождений: 90–94 — S. consularis; 95 — S. marginicollis; 96–97, 103–105 — S. stenoderus; 98–102 — S. lissoderus; 90–91, 101–102, 104 — северный Таиланд; 92 — Пров. ЗЯлай; 93, 96 — нац. парк Пухоат; 94 — нац. парк Кего; 97 — Тамдао; 98–100, 103 — ИрдиЯ; 105 — нац. парк Сонгтхань.