Orthogonius variabilis Tian, Deuve & Felix

Tian, Mingyi, Deuve, Thierry & Felix, Ron, 2012, Orthogonius species and diversity in Thailand (Coleoptera, Caraboidea, Orthogoniini), a result from the TIGER project, ZooKeys 164, pp. 51-90 : 68-73

Orthogonius variabilis Tian, Deuve & Felix sp. n. Figures 131525

Diagnosis.

Medium to quite small sized, ligula quadrisetose or sexsetose (in 4 paratypes), aedeagus somewhat similar to that of Orthogonius perakensis Tian & Deuve, 2006; elytral interval 3 with two setiferous pores (middle pore absent); elytra obliquely and sinuately truncate, with apical inner angles acute and sharp.

Length: 9.0-13.5 mm; width: 4.0-5.0 mm. Habitus as in Figure 13-15.

Description.

Body dark brown to yellow (That means the coloration is variable for some species of Orthogoniini , and the size too, not only shapes, but legs, pronotum, elytra, head and so on as well).

Body with varied coloration: from yellowish to black.

Upper surface smooth and glabrous, impunctate (but punctate in one paratype), elytral intervals each with an irregular row of tiny punctures along median portion; moderately shiny.

Microsculptural meshes densely isodiametric on elytra, irregularly and densely on head and pronotum.

Head stout, slightly wider than long, eyes very large and strongly prominent; frons and vertex moderately convex, frontal impressions small and fovea-like, clypeus bisetose, surface with a transverse impression and a median fovea near base; labrum sexsetose, frontal margin almost straight; ligula short, quadrisetose (sexsetose in a few individuals) at apex; palpi slender, subcylindrical, maxillary palpomere 4 longer than 3, palpomere 3 glabrous, except several setae at apex; maxillary palpomere 4 glabrous with very short setae; labial palpomere 3 slightly shorter than palpomere 2, palpomere 3 with a few setae at base; labial palpomere 2 bisetose in inner margin, and with two or three additional setae at subapex and apex; palpiger asetose, mentum and submentum each with one pair of setae; mentum without median tooth. Antennae moderate, extended to middle of elytra; pubescent from basal 1/3 of antennomere 4; antennomere 3 slightly shorter than antennomere 4.

Pronotum transverse, widest at about middle, PW/PL=1.17-1.22, disc slightly and evenly convex, both angles broadly rounded, both basal and fore margins beaded, lateral expanded margins wide, rather flat or somewhat reflexed; fore and hind transverse impressions distinct, basal foveae well-marked.

Elytra elongate ovate, EL/EW=1.7; moderately convex, basal border complete, shoulders broadly square; sides more or less parallel at middle, widest at about middle; striae deep, punctate-striate; intervals moderately convex, and subequal in width in middle; apex quite narrowly and obliquely truncate, outer angle well marked, inner angle sharp and denticulate; interval 3 with two setiferous pores (the middle pore absent); interval 7 simple.

Legs slender. Fore tibiae with apical outer angle obtuse; outer margin distinctly serrate; middle and hind coxae smooth and glabrous; middle tibiae evenly curved, gradually dilated towards apex; hind tibiae slender, apical spurs short and sharp, tarsomere 1 slightly longer than 2, tarsomere 3 distinctly longer than 4, tarsomere 4 bilobed; fore tarsi much wider than middle and hind ones; all tarsal claws strongly pectinate.

Prosternal process unbordered at apex. Apical margin of abdominal ventrite VII of male narrowly but distinctly emarginate at apical margin.

Male genitalia (Figure 25): the median lobe of the aedeagus somewhat stout, slightly or evenly expanded at middle portion; dorsal opening wide and long; in dorsal view apical lamella very short,, broadly pointed at apex.

Remarks.

This species differs from the Perakean species, Orthogonius perakensis Tian & Deuve, 2006, by its slender and flat body; and is easily separated from Orthogonius perroti Tian & Deuve, 2006 by the shape of its elytral apex.

Variability.

To treat this species is somewhat a challenge, because of the variability in several important characters such as coloration, shape of pronotum, elytral apex, aedeagus and middle tibia, and seta number on ligula. Several species might be “recognized” if there were only a few individuals available. Fortunately the large series of the specimens make it possible to realize the complicated variations of this species. The variations appeared in the following aspects: (1) sized: 9.0-13.5 mm; (2) coloration: from pure yellowish (4 ex), brown (24 ex), dark brown (13 ex), then to black (10 ex). Among Chinese specimens, five are bicoloured on the elytra (Fig. 15); (3) generally the apex of elytra of this species distinctly obliquely truncate, but in one male paratype the outer angle of apical elytra rounded and less sinuate, and inner angle less pointed; (4) pronotum: narrow to wide, and intermediate shapes, occurring in specimens of different size and coloration; (5) middle tibia: slightly curved (majority) or distinctly curved (11 ex); slightly dilated (29 ex) or strongly dilated in median portion; (6) aedeagus: stouter (6 ex) or a little more elongate at apex in dorsal view; (7) ligula: generally quadrisetose, only sexsetose in three specimens in Thianland species (but on the contrary, sexsetose in most Chinese specimens); and (8) punctures: generally impunctate, but one specimen distinctly punctate on vertex of the head.

According to Chaudoir (1871), presence of a sexsetose ligula is one main character for the genus Hexachaetus Chaudoir. Nonetheless, we treat this species as a member of Orthogonius considering that the number of setae on the ligula is variable.

Material examined.

Holotype: male, "Thailand: Phetchabun: Thung Salaeng Luang NP, Gang Wang Nam Yen, 16°37.531'N, 100°53.745'E, 721 m, 24-31.v.2007, Malaise trap, Pongpitak Pranee & Sathit leg., T2085", in QSBG.

Paratypes.

Thailand. 2 males, ibid; 1 male, "Thailand: Phitsanulok: Thung Salaeng Luang NP, moist evergreen, 16°50.641'N, 100°52.894'E, 557 m, 11.viii.2006-18.viii.2006, Malaise trap, Pongpitak Pranee leg., T566"; 1 male, "Thailand: Phetchabum, Thung Salaeng Luang NP, Gang Wang Nam Yen, pine forest, 16° 36.284N, 100° 53.128E, 749 m, Malaise trap, 29. vi– 6.vii.2007, Pongpitak Pranee & Sathit leg., T 2066"; 15 males, "Thailand: Nakhon Nayok: Khao Yai NP, entrance of Hnong Pak Chee Trail, 14°27.167'N, 101°21.85'E, 758 m, 26.v.2007-2.vi.2007, Malaise traps, Wirat Sukho leg., T2272"; 1 male, "Thailand: Phetchabum, Thung Salaeng Luang NP, Gang Wang Nam Yen, pine forest, 16° 35.789N, 100° 52.769E, 723 m, Malaise trap, 6-13.vii.2007, Pongpitak Pranee & Sathit leg., T 2068"; 2 males, "Thailand: Nakhon Nayok: Khao Yai NP, entrance of Hnong Pak Chee Trail, 14°27.167'N, 101°21.85'E, 758 m, 5-12.v.2007, Malaise traps, Pong Sandao leg., T2263"; 3 males, "Thailand: Nakhon Ratchasima: Khao Yai NP, Cobra zone near fire protection office, 14°28.285'N, 101°22.57'E, 751 m, 5-12.vi.2007, Malaise trap, Wirat Sukho leg., T2222"; 1 male, "Thailand: Phetchabun: Nam Nao NP, Checkpoint, 16°43.695'N, 101°33.797'E, 921 m, 27.ii.2007-1.iii.2007, Litter sample, Noopean Hongyothi & Leng Janteab leg., T2275"; 7 males, "Thailand: Nakhon Nayok: Khao Yai NP, entrance of Hnong Pak Chee Trail, 14°27.167'N, 101°21.85'E, 758 m, 19-26.v.2007, Malaise traps, Wirat Sukho leg., T2269"; 1 male, "Thailand: Nakhon Ratchasima: Khao Yai NP, Cobra zone near fire protection office, 14° 28.285N, 101°22.57'E, 751 m, 12-19.vi.2007, Malaise trap, Wirat Sukho leg., T2225"; 2 males, "Thailand: Nakhon Ratchasima: Khao Yai NP, Cobra zone near fire protection office, 14° 28.524N, 101°22.928'E, 757 m, 19-26.vi.2007, Malaise trap, Wirat Sukho leg., T2227"; 3 males, "Thailand: Nakhon Nayok: Khao Yai NP, entrance of Hnong Pak Chee Trail, 14°27.119'N, 101°21.482'E, 699 m, 19-26.v.2007, Malaise traps, Wirat Sukho leg., T2271"; 1 male, "Thailand: Nakhon Ratchasima: Khao Yai NP, Cobra zone near fire protection office, 14° 28.524N, 101°22.928'E, 757 m, 12-19.vi.2007, Malaise trap, Pong Sandao leg., T2224"; 1 male, "Thailand: Nakhon Ratchasima: Khao Yai NP, Cobra zone near fire protection office, 14°28.524'N, 101°22.928'E, 757 m, 5-12.vi.2007, Malaise trap, Pong Sandao leg., T2221"; 2 males, "Thailand: Nakhon Ratchasima: Khao Yai NP, Elephant Trail near fire protection office, 14°28.285'N, 101°22.57'E, 751 m, 26.vi.2007-2.vii.2007, Malaise trap, Wirat Sukho leg., T2231"; 1 male, "Thailand: Phetchabun: Thung Salaeng Luang NP, pine forest; Gang Wang Nam Yen, 16°35.805'N, 100°52.286'E, 726 m, 22-29.vi.2007, Malaise trap, Pongpitak & Sathit leg., T2064"; 2 males, "Thailand: Phetchabun: Thung Salaeng Luang NP, pine forest; Gang Wang Nam Yen, 16°36.284'N, 100°53.128'E, 749 m, 18-19.vi.2007, Pan traps, Pongpitak & Sathit leg., T2054"; 2 males, "Thailand: Phetchabun: Thung Salaeng Luang NP, pine forest; Gang Wang Nam Yen, 16°36.284'N, 100°53.128'E, 749 m, 20-21.vi.2007, Pan traps, Pongpitak & Sathit leg., T2056"; 1 male, "Thailand: Phetchabun: Thung Salaeng Luang NP: Gang Wang Nam Yen, 750 m, 16°36.587'N, 100°53.395'E; 17-24.v.2007, Pongpitak Pranee & Sathit leg., T2080"; 1 male, "Thailand: Phetchabum, Thung Salaeng Luang NP, Gang Wang Nam Yen, 16 °37.178'N, 100°.53.504'E, 706 m, Malaise trap, 17-24.v.2007, Pongpitak Pranee & Sathit leg., T2081", deposited in QSBG, MNHN, SCAU and CRF, respectively. China. 5 males and 5 females, "China: Yunnan, Jinghong, Banna NR, Mandian (forest), 22°12.961'N, 100°66.612'E, 746 m, Flying-stop trap, 26.v.2009, Meng Lingzeng leg."; 6 males and 18 females, ibid, 06.vi.2009; 1 male and 1 female, ibid, 26.vi.2009; 4 males and 3 females, ibid, 16.vi.2009; 3 females, ibid, pitfall trap 16.vi.2009; 1 male, ibid, rubber forest, 26.vi.2009; 1 male and 3 females, ibid, 16.v.2009; 1 female, ibid, 22°13.059'N, 100°66.817'E, 753 m, 16.vi.2009; 1 female, ibid, 26.vi.2009; 1 female, ibid, 26.v.2009; 1 female, ibid, 16.v.2009; 1 female, ibid, 06.vi.2009; 2 males and 1 female, "China: Yunnan, Jinghong, Banna NR, Anmaxinzhai (forest), 22°19.577'N, 100°64.532'E, 772 m, Flying-stop trap, 16.vi.2009, Meng Lingzeng leg."; 1 male and 1 female, ibid, 26.vi.2009; 2 males, ibid, 06.vi.2009; 1 male, ibid, 6.vi.2009; 1 male, "China: Yunnan, Jinghong, Banna NR, Guomengshan (paddy-field), 22°24.527'N, 100°60.380'E, 1110 m, Malaise, 26.v.2009, Meng Lingzeng leg."; 1 female, ibid, 26.vi.2009; 1 male, ibid, forest, 22°24.644'N, 100°60.616'E, 1114 m, 26.vi.2009; 1 female, ibid, 22°24.526'N, 100°60.411'E, 1107 m, 06.vi.2009; 1 male and 1 female, ibid, 6.vi.2009; 1 female, ibid, pitfall trap, 06.vi.2009; 2 males and 1 female, "China: Yunnan, Jinghong, Banna NR, Mandian (rubber forest), 22°13.059'N, 100°66.817'E, 753 m, Flying-stop trap, 16.v.2009, Meng Lingzeng leg."; 4 males and 1 female, "China: Yunnan, Jinghong, Banna NR, Danuoyou (waste land), 22°20.699'N, 100°63.761'E, 770 m, Malaise, 16.v.2009, Meng Lingzeng leg."; 1 female, ibid, 6.vi.2009; 1 male and 1 female, "China: Yunnan, Jinghong, Banna NR, Naban tea garden (waste land), 22°15.857'N, 100°66.529'E, 709 m, Malaise, 26.v.2009, Meng Lingzeng leg."; 1 female, ibid, 6.vi.2009; 1 female, ibid, 16.v.2009; 1 male, ibid, 22°13.091'N, 100°66.861'E, 689 m, 26.v.2009; 1 male, ibid, rubber forest, 22°15.843'N, 100°66.487'E, 732 m, Yellow-pot, 26.v.2009; 1 female, ibid, Malaise; 1 male and 3 females, ibid, forest, 22°15.810'N, 100°66.543'E, 729 m, Flying-stop trap; 1 female, ibid, 26.v.2009; 1 male, ibid, Malaise; 1 male, ibid, 16.v.2009; 2 females, ibid, 22°15.843'N, 100°66.487'E, 732 m, 26.vi.2009;1 female, "China: Yunnan, Jinghong, Banna NR, Jinghong Farm, rubber forest, 22°10.607'N, 100°68.500'E, 759 m, Malaise, 16.v.2009, Meng Lingzeng leg."; all are deposited in IOZ, except 5 males and 5 females in SCAU.

Etymology.

The species name, “variabilis”, means changeable and refers to the varied characters of this new species.

Distribution.

Thailand and China.

Unidentified materials

There are 27 specimens still not identified. All of them are females except one male (from Khao Pu-Khao Ya National Park, Trang), from which the aedeagus has been lost. Without reference to male genital characteristics, it is almost impossible to identify the Orthogonius species which belonging to either Orthogonius longicornis species group (viz. Orthogonius mouhoti , Orthogonius thaicus , Orthogonius pseudochaudoiri , Orthogonius nahaeo , Orthogonius loeicus , Orthogonius constrictus , Orthogonius vari , Orthogonius kirirom , Orthogonius pinophilus , Orthogonius gracililamella , Orthogonius longicornis , Orthogonius pseudolongicornis etc.) or Orthogonius alternans species group (viz. O. taghavianae, Orthogonius paris , Orthogonius thaiensis , Orthogonius pangi , Orthogonius huananoides etc.) in Thailand and its adjacent countries.