Bembidion (Peryphanes) sanatum iwanai Makarov et Sundukov, 2021

Makarov, K. V. & Sundukov, Yu. N., 2021, A new subspecies of Bembidion sanatum (Coleoptera: Carabidae) endemic to the Mendeleev Volcano (Kunashir Island, Russia), Far Eastern Entomologist 440, pp. 13-24 : 15-19

Bembidion (Peryphanes) sanatum iwanai Makarov et Sundukov , ssp. n.

http://zoobank.org/NomenclaturalActs/ AB33AD02-E50F-4FBC-BC41-A0F9533AC812

Figs 1–2 , 5–6, 9–10, 13–14 , 17–19, 23–25, 28–29

TYPE MATERIAL. Holotype – ♂, Russia: Kunashir Island , valley of Kislaya River,

below hot springs, 18. VI 2011, leg. A. Matalin ( ZISP) . Paratypes: the same label as the holotype, 1 ♀ ( MPU) ; Kunashir Island , Mendeleev Volcano, source of Kislaya River, below the solfatara field, 3.VIII 2016, 1 ♂, 1 ♀, leg. Yu. & L. Sundukov ( FEB) ; the same locality but 22.IX 2016, 15 ♂, 17 ♀, leg. Yu. Sundukov ( ZISP, ZMMU, MPU, FEB) ; the same locality but 15.VII 2017, 6 ♂, 9 ♀, leg. Yu. & L. Sundukov ( FEB) .

COMPARATIVE MATERIAL. Bembidion (Peryphanes) sanatum sanatum Bates,

1883. Japan: Honshu Island, Mount Hikageyama Jyoushu , Gunma Pref., 18.IX 1993, 2 ♂ , 2

♀, leg. S. Morita ( ZISP, MPU) .

Measured: 8 ♂, 7 ♀; genital preparate: 5 ♂; 5 ♀ .

DESCRIPTION. Body moderately convex; TL = 5.1–6.3 mm, EW = 2.2–2.7 mm.

Head and pronotum dark brown, with intense blue shine; elytra resin-brown or brownish with slightly darkened apices; mandibles brown, with blackened apices and middle part;

palps, antennae and legs pale brown; ventral surface black or tar-brown ( Figs 1, 2 ).

Dorsal surface shiny, elytral microsculpture (better visible in females) formed by thin transverse lines ( Figs 9, 10 ), barely visible at x56. Head and pronotum with scattered fine punctures; on the elytra, only striae are punctured.

Basic measurements (30 specimens): HW 1.08–1.22, M 1.13; HL 0.83–0.97, M 0.91; PA

0.98–1.12, M 1.05; PW 1.36–1.62, M 1.46; PB 1.03–1.22, M 1.13; PLt 1.13–1.35, M 1.23;

PLm 1.09–1.21, M 1.16; EW 2.28–2.60, M 2.42; EL 3.43–3.98, M 3.66; TL 5.43–5.94, M

5.65.

Head normal, moderately convex, slightly transverse (HW/HL = 1.17–1.33, M 1.26).

Eyes small, moderately convex. Antennae slender, long, 0.85–0.93 times as long as elytra in both sexes; 2nd antennomere shortest; 3rd to 10th 1.2–1.6 times as long as 2nd one; scape

1.2–1.3 times thicker than other antennomeres; ratio of antennomeres in one male = 19: 14:

21.5: 21.5: 21: 19: 18: 18: 17.5: 17: 22.5, in one female = 17: 14: 22: 21: 20: 19: 18: 17: 17.5:

17: 20.5. Mandibles relatively short, slender, with pointed apices. Labrum weakly transverse,

with six setae along a straight anterior margin. Clypeus slightly transverse, hexagonal, with two lateral setae in anterior third. Tooth of mentum rather large, wide, narrowly rounded at apex, with two basal setae. Submentum on each side with one long and one short seta at posterior margin, and with one long seta at anterior angle. Gula smooth. Temples short, about

1/3 diameter of eye, smoothly merging into a wide neck. Two supraorbital setae in the middle and at posterior margin of eye. Frontal grooves deep and wide, slightly projecting beyond anterior supraorbital setae; weakly converging anteriorly from setae to clypeus,

sharply diverging on clypeus to its lateral margins; grooves and area behind apex of frontal grooves with scattered, but rather coarse punctures.

Pronotum ( Figs 5, 6 ) cordate, regularly and moderately convex, slightly transverse

(PW/PLm = 1.21–1.35, M 1.26), wider than head (PW/HW = 1.23–1.34, M 1.30), with maximum width at 3/5 off base. Anterior margin straight, distinctly bordered from anterior angles towards 2/3 to midline. Anterior angles not projecting forward, with shortly pointed apices. Lateral sides rather strongly and uniformly convex, long and rectilinear before posterior angles. Lateral margins narrow throughout; with two lateral setae on each side:

2 – female; 3, 4 – B. sanatum sanatum : 3 – male, 4 – female.

before maximum width and at posterior angles. Base slightly and uniformly convex throughout, slightly wider than anterior margin (PB/PA = 1.04–1.11, M 1.08). Posterior angles distinct, rectangular, pointed at apices. Midline thin, distinct from anterior margin to a basal transverse bulge. Anterior transverse impression very weak or absent, often distinctly punctate in middle part. Basal fovea large, rounded, deep; their basal half and area between them rather coarsely punctured.

8, 11, 12, 15, 16 – B. sanatum sanatum ; 5–8 – pronotum; 9–12 – elytral striation; 13–16 –

microsculpture of elytra near series umbilicata; 5, 7, 9, 11, 13, 15 – males; 6, 8, 10, 12, 14, 16 –

females.

Elytra ( Figs 1, 2 , 9, 10 ) oval, wide (EL/EW = 1.45–1.62, M 1.53; EW/PW = 1.56–1.73,

M 1.66), long (EL/PLt = 2.87–3.18, M 2.98), rather strongly convex, with maximum width near 2/3 basal part. Shoulders prominent regularly rounded. Basal border reaching the apex of 5th groove, smoothly passing into lateral margin. Lateral sides in anterior half slightly convex, in posterior half regularly and arcuately narrowed towards apices; preapical sinuation absent. Apical angle rounded, forming a short gap between elytra. 1st–6th grooves small, superficial at apex, finely punctured throughout; 7th groove smoothed, outlined only by punctures in basal half, at apex with one apical and one preapical pore. Parascutellar stria rather long finely punctured, parallel to suture. Elytral intervals flat throughout or 1st–5th

barely convex in basal half. Scutellar pore rather large, joining with 1st and 2nd striae at base; 3rd interval with two small discal pores placed near 3rd stria at 1/3 or 2/3 off base,

respectively. Series umbilicata consisting of eight setae: four in humeral group, two at 2/3 off base, and two near apex. Hind wings well-developed.

Ventral surface smooth, impunctate. Metasternal process pointed at apex, sharply bordered. Metepisterna long, along outer margin approximately twice as long as wide along anterior margin (measured in two males and one female). Abdominal sternites simple, each with one pair of setae, with neither additional hairs nor setae. Anal sternite in males with microsculpture of fine transverse lines, with two apical setae; in females with microsculpture of barely noticeable, strongly transverse cells, with four apical setae.

Legs long, slender; hind tarsus 0.79–0.89 times as long as hind tibia; ratio of metatarsomeres 1–5 as 14: 6: 6: 4: 13; in males, the 1st protarsomere strongly enlarged, and the 2nd moderately enlarged.

Male genitalia. Aedeagus ( Figs 17, 18 ) large, about half as long as elytra (AL/EL = 0.53–

0.55), with prominent basal sclerites. Lamella short, with a rounded apex; ventral surface of aedeagus without projection. Ribbon brush large, entirely protruding from basal part of aedeagus. Basal chitin platelet well-developed, extended anteriorly; ventral chitin platelet barely visible. Main sclerite long, its distal part a long flagellum running side by side with spur of lamina 1 (lama paracopulatrice); base of lamina 1 rounded ( Figs 23–25 ). Left paramere ( Fig.

19) wide, triangular, with a small, trapezoidal, outer lobe; right paramere narrow, with a large outer blade; their chaetotaxy variable: left paramere with two (rarely a single) apical and two subapical setae, right paramere with three (rarely two) apical and one or two subapical setae.

Female genitalia ( Figs 28, 29 ). Spermatheca duct long, well-sclerotized, with five or six revolutions. Spermatheca with two chambers subequal in length; basal chamber noticeably asymmetric, convex on one side with gland opening at apex, apical chamber slightly curved.

DIAGNOSIS. By the size, colouration, and proportions, B. sanatum iwanai ssp. n. is similar to the nominative subspecies, but the pronotum is slightly larger (PLm/EL 0.32, vs.

0.31; PW/EW 0.61, vs. 0.69). The microsculpture of the outer elytral intervals is less strongly developed than in the nominative subspecies, while the 7 th and 8 th elytral intervals in the new subspecies are usually narrower than 6 th (0.9–1.1, vs. 1.0– 1.2 in the nominative subspecies).

The lamella of the aedeagus is somewhat narrower; the basal part of lamina 1 is rounded (vs.

angular in the nominative subspecies). The spermatheca duct shows a lower number of convolutions (5–6, vs. 7–8 in the nominative subspecies).

DISTRIBUTION AND HABITAT. Known only from the type locality, i.e. the valley of

Kislaya that stems from the northeastern solfatara field of the Mendeleyev Volcano. Beetles are encountered under riverside stones in the middle flow part of the river where water temperatures are already lower, but both mineralization and acidity remain considerable ( Figs 32, 33 ).

ETYMOLOGY. The type series of the new subspecies was collected in the valley of

Kislaya River where sulfur had previously been mined. Thus, the epithet comes from the

Ainu “ iwanai ”, meaning “a valley with sulphur” (Batchelor, 1905: 42).

sanatum iwanai, ssp. n.; 20–22, 26–27, 30–31 – B. sanatum sanatum ; 17, 18, 20, 21 –

aedeagus; 19, 22 – parameres; 23–27 – basal part of lamina 1; 28–31 – spermatheca.

Figures

Figs 1–4. Bembidion sanatum, dorsal habitus: 1, 2 – B. sanatum iwanai, ssp. n.: 1 – male,

Figs 5–16. Bembidion sanatum, detals: 5, 6, 9, 10, 13,14 – B. sanatum iwanai, ssp. n.; 7,

Figs 17–31. Male and female genitals of Bembidion sanatum: 17–19, 23–25, 28–29 – B.

Figs 32–33. Habitat of Bembidion sanatum iwanai, ssp. n.: 32 – upstream of Kislaya River; 33 – the bank of Kislaya River in the middle reaches.