Aleochara (Triochara) nubis Assing 1995

Aleochara (Triochara) nubis (Assing, 1995)

(Figs. 61–64, 86–92, 98–100, 104)

Triochara nubis Assing, 1995: 230 (diagnostic key to species of genus), 232 (original description; type locality: “ RUSSIA, Sakhalin, Korsakov distr., Ismenhyroye lake”); Naomi et al., 2000: 107 (record from Paramushir Is., Kuril Islands). Aleochara (Triochara) nubis (Assing, 1995); Maus & Ashe, 1998c (online) (world checklist of subgenus; bionomics); Maruyama, 2002: 18 (record from Japan (Hokkaidô)); Smetana, 2004: 358 (catalogue of Palaearctic species of Aleocharinae); Frank & Ahn, 2011: 20 (checklist of coastal Staphylinidae of world).

Type specimens. Not examined.

Non-type specimens. JAPAN: [Hokkaidô]: 3 3, 1 Ƥ, 4 sex?, Hamamatsu, Nemuro-shi (43.206N, 145.528E), 14 VI 2010, Yamamoto-S. (under seaweed on sandy beach; cYam); 2 sex?, Ochiishi, Nemuro-shi (43.607N, 145.286E *), 24 VIII 1999, Maruyama-M. (under seaweed on sandy beach; cMar); 1 sex?, Notsuke (Notsuke-zaki peninsulae), Betsukai-chô, Notsuke-gun (43.607N, 145.286E), 14 IX 2009, Ôhara-M., Yamamoto-H. and Furuta- M. (43°36ʹ26ʺN, 145°17ʹ0 8ʺE; under seaweed (Laminaria sp.) and eel grass (Zostera sp.); HUM: HK-09-MO-100/ SI); 1 3, 2 Ƥ, Shibetsu, Nemuro-shi (43.656N, 145.136E *), 18 VII 1977, Naomi-S.I. (KUM); 1 sex?, Koitoi, Shiranuka-chô, Shiranuka-gun, (42.982N, 144.163E), 19 VIII 2005, Kishimoto-K. (KUM); 1 sex?, Ôtsuminatomachi, Toyokoro-chô, Nakagawa-gun (42.667N, 143.628E), 26 VII 2009, Ôhara-M. (42°40ʹ0 2ʺN, 143°37ʹ41ʺE; under seaweed (Sargassum sp.); HUM: HK-09-MO-059/SA); 1 sex?, Ôkishi (near Ôkishi tunnel), Toyoura-chô, Abuta-gun (42.587N, 140.675E *), 15 IX 1997, Ôhara-M. (under seaweed on beach; KUM); 1 sex?, Sawara, Morimachi, Kayabe-gun (42.123N, 140.647E), 15 VII 2009, Ôhara-M. (42°07ʹ23ʺN, 140°38ʹ50ʺE; under seaweed (Sargassum sp.); HUM: HK-09-MO-040/SA).

Other specimens. RUSSIA: Kuril Islands: [Paramushir Is.]: 4 3, 8 Ƥ, Medvezhiy Waterfall, Shelekhovo (50.367N- 50.378N, 155.611E- 155.656E), 18 VII 1997, Saitô-A. (50°22.012ʹN -50°22.694ʹN, 155°36.677ʹE - 155°39.380ʹE; alt. 0-10m; CBM: CBM-ZI 81532(-81543)). [Kharimkotan Is.]: 3 sex?, Severgine bay (49.181N, 154.466E), 8 VIII 1996, Ôhara-M. (49°10ʹ51ʺN, 154°27ʹ59ʺE; hand picking; under pebble and logs on sandy beach; IKIP; HUM: KH-96-MO-022B). [Kraternaya Ysnkicha Is.]: 5 3, 2 Ƥ, 25 sex?, at entrance of the island (47.515N, 152.817E), 14 VIII 1995, Ôhara-M. (47°30ʹ54ʺN, 152°49ʹ0 0ʺE; IKIP; HUM: US-95-MO-021). [Simshir Is.]: 1 Ƥ, Malaya bay (47.087N, 152.131E), 18 VIII 1995, Ôhara-M. (N47°05ʹ14ʺ, E152°07ʹ51ʺ; hand pick up; under logs and rocks on shore; IKIP; HUM: SI-95-MO-032). [Chirupoi Is.]: 1 3, 1 sex?, Peschanaya bay (46.548N, 150.906E), 23 VIII 1995, Ôhara-M. (46°32ʹ53ʺN, 150°54ʹ22ʺE; under seaweed on sandy beach; IKIP; HUM: CH-95-MO-048). [Urup Is.]: 1 sex?, inland coastal margin of Natalie bay, envisions of Obzhitaya river, in small cave of rockface near river mouth at east end of cove (46.101N, 150.175E), 7 VIII 1995, Urbain-B.K. (46°05ʹ85ʺN, 150°09ʹ91ʺE; by hand with forceps; in, on, and under rocks in and around small cave along coast; alt. 1m; IKIP; HUM: UR-95-BKU-028); 1 3, near mouth of Vesetaya river, Natalii bay (46.094N, 150.142E), 6 VIII 1995, Ôhara-M. (46°05ʹ38ʺN, 150°08ʹ33ʺE; hand pick up; under rocks; IKIP; HUM: UR-95-MO-006); 1 3, inland coastal margin of Otkrytyi bay; environs of Shabalina river (45.864N, 149.794E), 4 VIII 1995 (15:00-16:00), Urbain-B.K. (45°51ʹ51ʺN, 149°46ʹ99ʺE; by hand; along coastal beach with fine sand; under logs; alt. 2m; sand temperature: 15 degree celcius; IKIP; HUM: UR-95-BKU-014); 1 3, 1 Ƥ, Otkrytyy bay (45.864N, 149.793E), 4 VIII 1995, Ôhara-M. (45°51ʹ49ʺN, 149°46ʹ95ʺE; under logs and rocks on shore; IKIP; HUM: UR-95-MO-002); 1 sex?, Tokotan, Otkrytyy bay (45.864N, 149.793E), 4 VIII 1995, Ôhara-M. (45°51ʹ49ʺN, 149°46ʹ95ʺE; under logs and rocks on shore; IKIP; HUM: UR-95-MO-001); 1 3, 6 sex?, Otkrytyy bay (45.851N, 149.770E), 5 VIII 1995, Ôhara-M. (45°51ʹ0 4ʺN, 149°46ʹ12ʺE; under seaweed along seashore; IKIP; HUM: UR-95-MO-005).

Redescription. Body (Fig. 61): small to large size, normally somewhat large; extremely robust and strongly sclerotized; somewhat thick but narrowly elongated; dorsal surface of entire body except for abdomen mat due to large hexagonal microstructures. Colour (Figs. 61–64): gland colour grayish black to dark gray with almost same (sometimes lighter) colour in elytra; legs, especially tarsal segments, brown to reddish brown: maxillary and labial palpi reddish brown to brownish brown; antennae dark brown to reddish brown. Head (Fig. 61): longitudinal deep furrows on each side of midline, connected by shallow transverse impression at base; dorsal surface with large hexagonal reticulations. Antennae: relatively thick and quite robust; shorter than combined length of head and pronotum; segment I, about 2.3 times as long as width; segment II prominently shorter than I, and strongly and apically dilated; segment III prominently shorter than II; segment IV slightly transverse; segment V to X moderately transverse; segment XI, about 1.3 times as long as broad; relative length (width) of segments from basal to apical: 9(4): 6(3): 4(3): 2.5(3.5): 2.5(4): 3(4.5): 3(4.5): 3(5): 3(5): 3.5(5): 6.5(5). Thorax: pronotum (Figs. 61–62) slightly wider than long (PW/PL =1.20), a little broader than head (PW/HW =1.28); somewhat constricted both apical and posterior margin; surface blackishly, but weakly shining due to large hexagonal microstructures on entire surface and shallow punctures with setae (connected with white line: Fig. 62); shallow punctures and furrows forming three-dimensional pattern; patterns diverse and varying within the species, [Typical type (see, Fig. 62)]: each of impunctured area largely similar to half-moon shape and elevated like dooms (yellow coloured: Fig. 62) and lack of cutting off by a row of setae around middle of each half-moon pattern, [Other type]: patterns irregular (not half-moon shape as in Fig. 62) and slightly elevated above; dorsal surface with longitudinal three somewhat deep and straight furrows along midline (blue line: Fig. 62). Inter coxal process of mesoventrite (Fig. 63) elongated and somewhat sharply pointed. Surface of mesoventrite (Figs. 63–64) somewhat rough and shining weakly. Inter coxal process of metaventrite (Fig. 63) short with rounded anterior margin. Legs: hindtibia short, about 0.9 times as long as elytra (measured along midline); relative lengths of tarsomeres from basal to apical: 6: 4: 4: 4: 8 in foretarsus, 8: 5: 5: 5: 10 in midtarsus, 10: 6: 6: 6: 12 in hindtarsus. Abdomen: posterior margin of tergite VIII (Figs. 86–87), with a row of thin and long several sensory setae; surface of tergite VIII and sternite VIII pubescent.

[Male]: posterior margin of tergite VIII (Fig. 86) almost truncate or slightly emarginated medially, with around 11 macrosetae. Sternite VIII (Fig. 88) with about 5 macrosetae and around 8 thin macrosetae; posterior margin pointed triangularly. Median lobe of aedeagus (Figs. 90–91) elongated, moderately narrowed apically, elongated pyriform in ventral view (Fig. 91); a pair of pointed large and oval subapico-ventral projections in lateral view (Fig. 90); apical lobe of median lobe isosceles shape in ventral view (Fig. 91); flagellum slightly shorter than the whole length of median lobe (Figs. 90–91).

[Female]: posterior margin of tergite VIII (Fig. 87) nearly truncate, with around 3 macrosetae and around 5 thin macrosetae. Posterior margin of sternite VIII weakly pointed (Fig. 89) with 4 large macrosetae and around 4 thinner macrosetae. Spermatheca (Fig. 92): head (sh) thick and large, more than twice longer than apical portion of spermathecal stem; spermathecal neck extremely short; basal portion of spermathecal stem narrowing toward base, with strong bent (<90°).

Measurements (male: n=10): BL, 3.72–4.95 (4.39±0.45); FBL, 1.82–2.23 (2.04±0.14); HL, 0.53–0.65 (0.61±0.04); HW, 0.61–0.74 (0.68±0.04); AL, 0.79–1.07 (0.96±0.09); PL, 0.64–0.81 (0.74±0.06); PW, 0.77–0.97 (0.89±0.07); EL, 0.66–0.80 (0.72±0.05); EW, 0.89–1.13 (1.03±0.08); HTL, 0.49–0.65 (0.59±0.05).

Measurements (female: n=10): BL, 3.34–5.00 (4.12±0.50); FBL, 1.86–2.24 (2.05±0.11); HL, 0.54–0.72 (0.61±0.05); HW, 0.63–0.79 (0.70±0.04); AL, 0.82–1.11 (0.93±0.09); PL, 0.62–0.87 (0.73±0.07); PW, 0.78–1.01 (0.88±0.06); EL, 0.62–0.80 (0.71±0.05); EW, 0.91–1.23 (1.03±0.09); HTL, 0.49–0.70 (0.57±0.06).

Confirmed distribution by authors. [JAPAN]: Hokkaidô (see, Fig. 104); [RUSSIA]: Kuril Islands: Paramushir Is., Kharimkotan Is., Kraternaya Ysnkicha Is., Simshir Is., Chirupoi Is., Urup Is.

Other localities in literature. [RUSSIA]: Far East: Sakhalin, Kamchatka Peninsula (Assing, 1995).

Diagnosis. Aleochara (Triochara) nubis is similar to A. zerchei in many points (e.g., posterior margin of tergite VIII in both sexes without a row of thick sensory setae). Although they share many characteristics, we found out some distinctions: distribution restricted to northern area (Hokkaidô, Japan (see, Fig. 104); Russian Far East; North Korea); usually large species, occasionally small; dorsal surface of forebody mat and not strongly shining; longitudinal subparallel furrows on head connected with a shallow impression (not by a deep furrow); impunctured areas (or lacking of that areas) on pronotum (Fig. 62) greatly varying within species, but prominent microstructures and hexagonal reticulations on dorsal surface; longitudinal sulci on dorsal surface of pronotum (Fig. 62) deep, normally straight lines; posterior margin of tergite VIII (Figs. 86–87) with a row of thin and long sensory setae as in A. zerchei; surface of both tergite VIII and sternite VIII (Figs. 86–89) pubescent. [Male]: posterior margin of sternite VIII (Fig. 88) pointed triangularly; subapico-ventral projections on median lobe of aedeagus large and oval, pointed apical-laterally in lateral aspect (Fig. 90). [Female]: base of (sb) very strongly curved (Fig. 92).

Remarks. Assing (1995) described this halophilous species from Sakhalin and Kamchatka Peninsula, Russia, and Maruyama (2002) later recorded it for the first time from Japan (Hokkaidô). Naomi et al. (2000) reported A. nubis from the Kuril Islands, but only from Paramushir Island. In this study, we present several new distributional records for the Kuril Islands. Our data suggest a wide ranging distribution for A. nubis throughout Far East Russia to Hokkaidô. These records also show that A. nubis is distributed only in the subarctic zone in East Asia. No specimen has been found from Honshû, Kyûshû, or Ryûkyû in Japan (see, Fig. 104). Mating behaviour (Fig. 100) was observed under drifted seaweed at Hamamatsu (Hokkaidô) (see, bionomics and distribution of Triochara).