Amphimenes medius, Fedorenko, 2010

Fedorenko, D. N., 2019, A revision of Amphimenes (Coleoptera: Carabidae: Lebiini), Russian Entomological Journal 28 (3), pp. 233-250 : 245-247

The medius species group.

The group includes five apterous soil-dwelling species, two from southern Vietnam, two from Central Vietnam, and one from northern Vietnam. Elytral seta d1 inserted close to base is their main distinctive feature.

3.5. Amphimenes (s. str.) acutipennis

Fedorenko , sp.n.

Figs 6 , 11–12 , 31 .

MATERIAL. Holotype ♂ ( ZMMU) : ‘ Vietnam, Kon Tum Province, Kon Plong Distr [ict]., 14°45 ' N / 108°18210 '' E, env. ngock Boc I Mt., h= 1200–1300 m, 8–23.IV.2015, D. Fedorenko leg.’. Paratypes ( ZISP, ZMMU, SIEE): 6♂♂, 3♀♀ , same data; ♂, ♀ , same data except 14°44 ' 20 '' N / 108°19 ' E, h= 1100–1200 m; 2♂♂, 3♀♀ , same data, except for 14°45 ' N 108°17 ' 51 '' E, h= 1300–1400 m, 8–10.VI.2016; ♂, ♀ , ‘ Vietnam, Gia Lai Province,~ 40 km ENE of Pleiku , 14°13 ' 09 '' N / 108°19 ' 48 '' E, Kon Ka Kinh Nat [io]n[al]. Park, h= 1470 m, 21– 30.V.2017, D. Fedorenko leg.’. Aedeagus examined in three males .

DESCRIPTION. Body apterous, large and slender ( Fig. 6 ), BL 10.1–11.9 mm. Black; mouthparts, including labrum, anterior half to two thirds of clypeus, antennae, tarsi and trochanters red; lateral margins of elytra and extreme lateral margins of pronotum barely translucent with reddish-brown (more distinctly translucent under spotlight). Sometimes antennomeres 3 and 4 infuscated. Microsculpture isodiametric, distinct yet slightly superficial on head, very coarse, granulate-aciculate over pronotum. Elytra with transverse, mostly moderately transverse, microsculpture becoming isodiametric on explanate lateral margins. As a result, head and elytra moderately shiny, much shinier than dull pronotum. Elytral cross-striated sculpture dense and conspicuous in basal half, becoming increasingly weak and sparse apicad until nearly indistinct before apex.

Head: eyes slightly flattened, twice as long as genae, these smoothly extended into neck. Posterior supra-ocular seta clearly behind posterior margin of eye (about 1/6 eye length distant from eye). Antennae very long, surpassing base of pronotum by about apical 4.5 antennomeres.

Pronotum subcordate, broadest at anterolateral seta a fourth from apex, only a fifth wider than long, PW/PL 1.18–1.23 (mean 1.20, n=5), PW/HW 1.45–1.48 (1.47). Base a third broader than apex, PB/PA 1.28–1.37 (1.34), straight medially, with lateral lobes evenly convex caudad, half as wide as and slightly produced beyond median part. Basal angles highly obtuse yet mostly distinct. Apex deeply sinuate; apical angles porrect, slightly acute and sharp. Sides evenly rounded in apical two thirds, gently sinuate behind. Disc slightly convex, with fine and dense transverse wrinkles. Lateral margins rather strongly reflexed, narrow anteriorly, moderately wide in basal half; lateral grooves fairly wide and more or less flat at bottom. Median line entire and moderately deep; basal transverse impression well defined, angulate or convex forward. Basal foveae deep, round, merged into reflexed lateral margin and thence fairly wide; each as a very shallow yet fairly wide groove reaching middle or just apical margin. Paramedian foveae as small and very shallow to indistinct pits or short longitudinal impressions a third from apex and equidistant from median line and lateral groove.

Elytra elliptic, EL/EW 1.41–1.61 (1.53), EW/PW 1.40– 1.52 (1.44), oblique from mesothoracic peduncle, with humeri rounded off, evenly rounded on sides, broadest at middle. Apical truncature oblique, deeply sinuate, more so close to acute and pointed posterolateral angles. Apices rectangular combined, with extreme tips slightly separate and sharp to blunt. Lateral margin very widely explanate behind the level of seta d1 and flat in horizontal plane. Striae deep; intervals convex. Interval 3 with three setae, D1/EL 0.16–0.18 (0.17, n=5×2), D2/EL 0.63–0.72 (0.67), D3/EL 0.91–0.94 (0.93).

Metepisternum 1.03–1.04 times as long as wide.

Tarsomere 5 with two pairs of ventral setae. Male profemur without tubercle, mesotrochanter with a small tubercle; mesotibia 5-tuberculate along inner margin.

Aedeagus ( Figs 11–12 , 31 ): as in A. giganteus , except that median lobe in lateral view is much broader medially than just behind basal bulb (vs. subequally wide), with apex in ventral view being slightly more curved to the left.

DIAGNOSIS. The largest species within the genus. It is similar to A. giganteus , except that that is smaller, with elytral base convex forward and outer angles obtuse and apically rounded, etc.

DISTRIBUTION. Known from two fairly close localities in central Vietnam (Gia Lai, Kon Tum).

NAME. Refers to acute posterolateral angles of the elytra.

HABITATS AND HABITS. This species occurs on the underside of logs and smaller tree fragments on the ground in monsoon forests at 1100–1470 m altitude. It lives syntopically with A. konplongensis sp.n. and/or A. basipunctatus sp.n.

3.6. Amphimenes (s. str.) basipunctatus

Fedorenko , sp.n.

Figs 7 , 17–18 , 33 .

MATERIAL. Holotype ♂ ( ZMMU): ‘ Vietnam, Kon Tum Prov [ince]., Chu Mom Ray National Park, 14°30 ' N / 107°42 ' 30 '' E, ngock To Lum mt. , h= 1100–1350 m 28.III–4.IV.2015, D. Fedorenko leg.’. Paratypes ( ZISP, ZMMU, SIEE), 7♂♂, 6♀♀ , same data; ♀ ( SIEE) , Vietnam, Kon Tum Province, Kon Plong Distr. , 14°45 ' N / 108°17 ' 51 '' E, env. ngock Boc 1 Mt., h= 1300–1400 m, 8–10.VI.2016, D. Fedorenko leg.; 2♂♂, 2♀♀ , ‘ Vietnam, Gia Lai Province, ~ 40 km ENE of Pleiku , 14°13 ' 09 '' N / 108°19 ' 48 '' E, Kon Ka Kinh Nat [io]n[al]. Park, h= 1470 m, 21–30.V.2017, D. Fedorenko leg.’; ♂, ♀ , same data except 14°13 ' 40 '' N / 108°18 ' 35 '' E, h= 1300–1380 m; ♂ , ‘ Vietnam, Quang Nam Prov., Nam Gian Distr., Song Thanh Natn. Park , 15°32 ' 51 '' N / 107°23 ' E, h= 1230 m, 23.IV–11.V.2019, leg. D.Fedorenko’; 3♂♂, ♀ , same data, except for either 15°34 ' 07 '' N / 107°23 ' 13 '' E, h= 1010 m; or 15°32–33 ' N, 103°22–23 ' E, h= 1100– 1230 m; or 15°33 ' 48 '' N / 107°23 ' 22 '' E, h= 1050 m; or 15°33 ' 19 '' N / 107°23 ' 29 '' E, h= 1070 m. Aedeagus examined in eight males .

DESCRIPTION. As for A. acutipennis sp.n. except as follows: Body ( Fig. 7 ) medium-sized, BL 6.7–8.7 mm. Black yet barely paler than A. acutipennis ; antennae entirely pale, tibiae and tarsi red or pale brown, or tibiae slightly darker than tarsi while distinctly paler than femora. Lateral margin of elytra more clearly translucent with reddish-yellow. Microsculpture coarse, isodiametric on head, granulate-aciculate on pronotum, much more superficial on elytra, consisting of very transverse meshes mixed with wider transverse meshes here and there; explanate lateral margin of elytra with isodiametric microsculpture. Head and pronotum subequally dull, elytra moderately shiny.

Antennae surpassing pronotal base by apical 3–3.5 antennomeres.

Pronotum cordate, much narrower relative to elytra, PW/ PL 1.16–1.21 (mean 1.18, n=5), PW/HW 1.42–1.50 (1.47). Base straight or indistinctly convex posteriad, on a level with gently rounded lateral lobes or barely produced, PB/PA 1.33–1.43 (1.38). Basal angles slightly to very obtuse. Basal foveae rather small and mostly not extended apicad. Paramedian foveae usually indistinct, situated midway between median line and narrow lateral grooves. Reflexed lateral margin slightly to moderately reflexed, narrow from apical angle to anterolateral seta, slightly and increasingly wider toward basal angles.

Elytra: EL/EW 1.41–1.47 (1.44), EW/PW 1.55–1.69 (1.59); base very narrow yet distinct; posterolateral angles very obtuse and rounded; apices obtuse and pointed combined. Apical truncature barely sinuate, more deeply near apex. Reflexed lateral margin slightly concave dorsally, wide medially, much narrower before and behind. Intervals convex, inner ones slightly convex to nearly flat. Interval 3 with three setae; d1 very close to base, D1/EL 0.09–0.12 (0.11, n=5×2), D2/EL 0.60–0.69 (0.66), D3/EL 0.89–0.93 (0.92).

Metepisternum short, ES3L/ES3W 0.85-1.0 (0.92, n=3).

In male, profemur without tubercle, mesotrochanter with a small tubercle, mesotibia with four tubercles along inner margin.

Aedeagus ( Figs 17–18 , 33 ): as in the previous species, except for apical lamella slenderer and nearly straight in ventral view.

DIAGNOSIS. This species is transitional from A. medius and A. tonkinensis sp.n. to A. giganteus and A. acutipennis sp.n. in size. The three species of this group, that share similar elytral chetome, A. basipunctatus sp.n., A. giganteus , and A. acutipennis sp.n., have distinctive elytral apices each. The apices are either contiguous and sharp, with indistinct sinuation outside, in A. basipunctatus sp.n. or slightly separate at sutural angle, with the apical truncature either deeply and evenly concave ( A. giganteus ) or very deeply concave just behind outer angle ( A. acutipennis sp.n.). For other differences see the key.

VARIATION. Specimens from the northern population (Quang N am) may be barely larger than those from southern ones, BL being 7.3–8.7 or 6.7–8.1 mm, respectively.

DISTRIBUTION. Central Vietnam (Gia Lai, Kon Tum) .

NAME. Refers to the anterior discal seta (d1) inserted closer to elytral base than in the congeners.

HABITATS AND HABITS. As for the previous species.

3.7. Amphimenes (s. str.) tonkinensis

Fedorenko , sp.n.

Fig. 8 .

MATERIAL. Holotype ♀ ( ZMMU): ‘N-Vietnam, 40 km WNW of Lao Cai, env. Y Ty, Bat Xat N [ational]P[ark], 22°36 ' 02 '' N / 103°37 ' 13 '' E, h= 2200 m, 4–14.VI.2019, leg. D.Fedorenko’.

DESCRIPTION. Body apterous, small ( Fig. 8 ), BL 6 mm, shiny black, with pronotum dull. Clypeus, except for brownish base, labrum, mouthparts, antennae, legs, gula, prosternum, hypomera, meso- and metaventrite, and abdominal sternite III between metacoxae red; abdomen widely reddish along middle, underside otherwise rather dark brown; reflexed lateral margins of elytra translucent with red, those of pronotum translucent with reddish-brown. Microsculpture isodiametric on head; pronotal microsculpture very coarse, granulate-aciculate in basal half and along sides, otherwise consisting of isodiametric or barely transverse meshes. Elytra with meshed microsculpture superficial, isodiametric or barely transverse. Elytral cross-striated sculpture vestigial, hardly traceable along middle of elytral intervals basally, nearly indistinct behind.

Head narrow, with eyes rather flat and small, as long as genae which almost smoothly extend into neck. Posterior supra-ocular seta distant far from posterior margin of eye. Antennae fairly short, surpassing base of pronotum by apical antennomere.

Pronotum narrow, subcordate, nearly square, broadest at anterolateral seta slightly less than a third (0.30) from apex, slightly wider than long, PW/PL 1.16, PW/HW 1.39. Base a fourth broader than apex, PB/PA 1.24, barely concave between lateral lobes; these convex caudad and more rounded laterally. Basal angles very obtuse and blunt. Apex deeply sinuate; apical angles porrect and acute. Sides evenly round- ed in apical three fourths, gently sinuate behind. Disc flattened. Lateral margins together with basal angles and laterobasal lobes strongly reflexed, slightly wider before than behind. Median line entire and moderately deep; basal transverse impression short and deep. Basal foveae short and deep, each extended apicad into a very shallow impression that disappears medially. Paramedian foveae indistinct.

Elytra elliptic, EL/EW 1.45, EW/PW 1.71, broadest medially, with common base narrow, humeri round yet traceable, and sides evenly rounded up to rounded posterolateral angles. Apical truncature oblique, slightly sinuate. Apices very slightly obtuse combined and nearly contiguous. Lateral margin rather widely explanate in inner three fifths. Striae deep, intervals slightly convex, almost flat on disc. Interval 3 with three setae, D1/EL 0.13, D2/EL 0.37/0.40, D3/EL 0.90/ 0.91 (0.93).

Metepisternum short, about as long as wide.

Tarsomere 5 with one pair of ventral setae, preapical.

DIAGNOSIS. Within the medius -group, this species is easily recognizable by the combination of the body small, with narrow forebody and pale appendages, nearly isodiametric elytral microsculpture, three elytral discal setae present, with seta d1 inserted before middle.

DISTRIBUTION. Known from the type locality only, that is on the Hoang Lien Mt. Ridge, Lao Cai, northern Vietnam .

NAME. Toponymic; refers to the former historical name of northern Vietnam.

HABITATS AND HABITS. The only female specimen was hand collected under a small tree fragment on the ground in a cloudy forest. The species appears to live syntopically with A. reflexicollis .

COMMENTS. Two elytral characters, nearly isodiametric microsculpture and seta d1 inserted distinctly before middle, are not characteristic of the other members of the medius -group and the species range is distinctive. Accordingly this species may require to be placed in the separate group of itself.

Figures

Figs 6–10. Dorsal habitus: 6 — Amphimenes acutipennis sp.n., ♂ paratype from Kon Plong District; 7 — A. basipunctatus sp.n., holotype; 8 — A. tonkinensis sp.n., holotype; 9 — A. konplongensis sp.n., holotype; 10 — A. femoralis sp.n., ♂ paratype. Рис. 6–10. Габитус дорЗально: 6 — Amphimenes acutipennis sp.n., паратип ♂ иЗ округа Конплонг; 7 — A. basipunctatus sp.n., голотип; 8 — A. tonkinensis sp.n., голотип; 9 — A. konplongensis sp.n., голотип; 10 — A. femoralis sp.n., паратип ♂.

Figs 11–20. Median lobe of aedeagus: 11–12 — Amphimenes acutipennis sp.n.; 13–14 — A. similis sp.n.; 15–16 — A. guttatus; 17– 18 — A. basipunctatus sp.n.; 19–20 — A. femoralis sp.n.; 11, 17, 19 — left aspect; 13, 15 — left ventrolateral aspect; 12, 18, 20 — right aspect; 14, 16 — right ventrolateral aspect. Scale bars: 0.5 mm. Рис. 10–19. СреднЯЯ долЯ Эдеагуса: 11–12 — Amphimenes acutipennis sp.n.; 13–14 — A. similis sp.n.; 15–16 — A. guttatus; 17–18 — A. basipunctatus sp.n.; 19–20 — A. femoralis sp.n.; 11, 17, 19 — слева; 13, 15 — слева и сниЗу; 12, 18, 20 — справа; 14, 16 — справа и сниЗу. МасШтаб: 0,5 мм.

Figs 31–38. Median lobe of aedeagus, ventral aspect: 31 — Amphimenes acutipennis sp.n.; 32 — A. piceus; 33 — A. basipunctatus sp.n.; 34 — A. subcostatus sp.n.; 35 — A. femoralis sp.n.; 36 — A. marginicollis sp.n.; 37 — A. bicoloripes sp.n.; 38 — A. konplongensis sp.n. Scale bars: 0.5 mm. Рис. 31–38. СреднЯЯ долЯ Эдеагуса, вентрально: 31 — Amphimenes acutipennis sp.n.; 32 — A. piceus; 33 — A. basipunctatus sp.n.; 34 — A. subcostatus sp.n.; 35 — A. femoralis sp.n.; 36 — A. marginicollis sp.n.; 37 — A. bicoloripes sp.n.; 38 — A. konplongensis sp.n. МасШтаб: 0,5 мм.