Lesticus lakhonus Tschitschérine, 1900

Fedorenko, D. N., 2022, New or little-known Lesticus Dejean, 1828 (Coleoptera: Carabidae: Pterostichini) from Vietnam, Russian Entomological Journal 31 (3), pp. 260-275 : 272

8. Lesticus lakhonus Tschitschérine, 1900 , stat.rest.

Figs 11 , 23 , 42–43 , 51–53.

Tschitschérine, 1900: 171 ( Laos: ‘Lakhon, sur le Mekong, …’).

MATERIAL. 24♂♂, 12♀♀ ( SIEE), Vietnam, Ha Tinh Prov., Vu Quang Natn. Park, Kim Quang env., h~ 70 m, 18°17´59´´N, 105°22´31´´E, flood-land forest, 24.V–1.VI.2022 (D. Fedorenko) ; ♂ ( SIEE), Ke Go Nature Reserve, 18°06´30´´N / 106°01´E, env. Mui Tru Station , h= 40 m 7–14.V.2015 (A. Abramov) ; ♀ ( SIEE), Quang Binh Province, Minh Hoa Distr., Ke Bang, env. Yen Hop , 16.IV.1999 (S. Kruskop) ; ♀ ( ZIN), Vietnam, Dak Lak Province, Yok Don Nature Reserve near Ban Don , 26.XI.1993 (A. Gorokhov) ; ♀ ( SIEE), Dong Nai Province, Cat Tien National Park , at light HQL 450, 17.V.2005 (D. Fedorenko). — Internal sac of aedeagus examined in four males.

DIAGNOSIS. A slender, medium-sized, macropterous species with long metepisterna. At least forebody dorsum bright metallic. Protarsomere 1 without ventral pad in female, metatarsus with a sharp anterolateral carina. Internal sac of aedeagus ( Figs 42–43 ) dorsal and helical, with a few rather small bulbs.

REDESCRIPTION. As for L. buqueti except as follows. BL 20.1–23.7 mm. Head and pronotum shiny, cupreous green, elytra shiny, purple green in male, black and rather dull, especially so toward lateral margin and toward apex, in female. Microsculpture imperceptible on head and pronotum, consisting of isodiametric or wide rectangular meshes, respectively; isodiametric and distinct on elytra, superficial (♂) or coarse (♀). Dorsal micropunctation dense, more or less distinct on head, hardly traceable on pronotum and elytra.

Head ( Fig. 11 ). Genae distinct in posterodorsal view, longer and slightly convex (vs. very short and straight in L. buqueti ). Frontal sulci sinuous and long, parallel before and behind, convex laterad in between, very deep to nearly obliterate behind the level of anterior supra-ocular seta. Neck constriction shallow. Antennae long, with about apical 2.5 segments surpassing elytral base. Maxillary and labial palps slender: terminal maxillary palpomere parallel-sided (♀) or subtriangular (♂), mp4W/L 0.31 or 0.38, respectively; terminal labial palpomere more triangular, lp3W/L 0.40–0.45 (♀) or 0.62 (♂).

Pronotum ( Fig. 23 ). Basal foveae shallow, more so toward lateral margin and thence barely separated from basal dilation of lateral bead; finely and sparsely punctate to impunctate yet slightly rugulose. Inner basal sulci rather deep at base, shallow or very so in front.

Elytra longer in male than in female (Tab. 1). Basal ridge inwardly reaching stria 1 or 2. Striae deep, distinctly punctate, finely on disc, with punctures becoming increasingly coarse toward both lateral margin and apex. Intervals convex (♂) or subconvex (♀), with those 1–5 subconvex except base and apex or flat in apical half, respectively. Interval 3 with three discal setae. USS: 22–23.

Propleura, sides of metaventrite, mes- and metepisterna, and abdominal sternite II along base coarsely and densely punctate; abdominal sternite II with a transverse row of coarse punctures. Metepisternum moderately long, est3L/W ratio1.29–1.33.

Legs. Meso- and metatarsi with sharp lateral carina. Mesofemur with 3–5 anteroventral setae.

GEOGRAPHIC DISTRIBUTION. Laos, Central and southern Vietnam.

HABITATS AND HABITS. As for L. nubilus .

COMMENTS. This little-known species was recently synonymized with L. chalcothorax [ Roux et al., 2016] because of no differences found between these two. Unfortunately these authors did not commented on the shape of the terminal maxillary or labial palpomere,whereas Tschitschérine [1900] pointed out that the two palpomeres were slender in the male holotype of L. lakhonus . Because these features have been found in no male L. buqueti (= L. chalcothorax ) examined by me, I consider the two species to be separate and accordingly revalidate L. lakhonus here.

Aedeagus of the only male examined has a distinctive, helical, internal sac (endophallus type IV) described on the example of L. insignis (Gestro, 1883) [ Zhu et al., 2018]. Accordingly this latter name is here used for the respective species group which also includes a new species described below.

Figures

Figs 1–12. Head: 1–2 — Lesticus nubilus, 2♂♂; 3 — L. attenuatus sp.n., ♂ paratype; 4 — L. p. praestans, ♂ from Cuc Phuong NP, Vietnam; 5 — L. p. mouhotii, ♀ from Mondulkiri Prov., Cambodia; 6 — L. auricollis, ♂ from Bac Giang Prov., Vietnam; 7–8 — L. verticillatus sp.n., ♂ paratype from Song Thanh NP and ♂ holotype; 9 — L. bellus sp.n., ♀ holotype; 10 — L. buqueti, ♀; 11 — L. lakhonus, ♀; 12 — L. laevis sp.n., ♂ holotype; 1, 10–11 — Cat Tien NP, Vietnam; 2 — Mae Vong env., Thailand. Рис. 1–12. Голова: 1–2 — Lesticus nubilus, 2♂♂; 3 — L. attenuatus sp.n., паратип ♂; 4 — L. p. praestans, ♂ иЗ Нац. парка Кыкфыонг, Вьетнам; 5 — L. p. mouhotii, ♀ иЗ пров. Мондулкири, Камбоджа; 6 — L. auricollis, ♂ иЗ пров. БакЗЯн, Вьетнам; 7–8 — L. verticillatus sp.n., паратип ♂ иЗ нац. парка Сонгтхань и голотип ♂; 9 — L. bellus sp.n., голотип ♀; 10 — L. buqueti, ♀; 11 — L. lakhonus, ♀; 12 — L. laevis sp.n., ♂ голотип; 1, 10–11 — Нац. парк Катьен, Вьетнам; 2 — окр. Мае Вонг, Таиланд.

Figs 13–24. Pronotum: 13–14 — Lesticus nubilus, 2♂♂; 15 — L. attenuatus sp.n., ♂ paratype; 16 — L. p. praestans, ♂ from Cuc Phuong NP, Vietnam; 17 — L. p. mouhotii, ♀ from Mondulkiri Prov., Cambodia; 18 — L. auricollis, ♂ from Bac Giang Prov., Vietnam; 19– 20 — L. verticillatus sp.n., ♂ paratype from Song Thanh NP and ♂ holotype; 21 — L. bellus sp.n., ♀ holotype; 22 — L. buqueti, ♀; 23 — L. lakhonus, ♀; 24 — L. laevis sp.n., ♂ holotype; 13, 22–23 — Cat Tien NP, Vietnam; 14 — Mae Vong env., Thailand. Рис. 13–24. Переднеспинка: 13–14 — Lesticus nubilus, 2♂♂; 15 — L. attenuatus sp.n., паратип ♂; 16 — L. p. praestans, ♂ иЗ Нац. парка Кыкфыонг, Вьетнам; 17 — L. p. mouhotii, ♀ иЗ пров. Мондулкири, Камбоджа; 18 — L. auricollis, ♂ иЗ пров. БакЗЯн, Вьетнам; 19–20 — L. verticillatus sp.n., паратип ♂ иЗ нац. парка Сонгтхань и голотип ♂; 21 — L. bellus sp.n., голотип ♀; 22 — L. buqueti, ♀; 23 — L. lakhonus, ♀; 24 — L. laevis sp.n., ♂ голотип; 13, 22–23 — Нац. парк Катьен, Вьетнам; 14 — окр. Мае Вонг, Таиланд.

Figs 40–45. Aedeagus, median lobe with everted and inflated internal sac: 40–41 — Lesticus buqueti, ♂♂ from Java (40) or Vietnam (41); 42–43 — L. lakhonus; 44–45 — L. laevis sp.n., holotype; 40–41, 43, 45 — right dorsolateral aspect; 42, 44 — left ventrolateral aspect; b, c, d, e — bulbs of internal sac. Scale bars 1 mm. Рис. 40–45. Эдеагус, среднЯЯ долЯ с вывернутым и надутым внутренним меШком: 40–41 — Lesticus buqueti, ♂♂ с Явы (40) и иЗ Вьетнама (41); 42–43 — L. lakhonus; 44–45 — L. laevis sp.n., голотип; 40–41, 43, 45 — справа и сверху; 42, 44 — слева и сниЗу; b, c, d, e — пуЗыри внутреннего меШка. МасШтаб: 1 мм.