Helophorus (Lihelophorus) ser Zaitzev, 1908

Angus, Robert B., Jia, Fenglong, Chen, Zhen-ning, Zhang, Ying, Vondráček, Dominik, Fikáček, Martin & Sw, London, 2016, Taxonomy, larval morphology and cytogenetics of Lihelophorus, the Tibetan endemic subgenus of Helophorus (Coleoptera: Hydrophiloidea), Acta Entomologica Musei Nationalis Pragae 56 (1), pp. 109-148 : 118-127

Helophorus (Lihelophorus) ser Zaitzev, 1908

( Figs 1d, f–g, i, l ; 2c–d, h–j ; 3d–g ; 4d–h ; 6a–e )

Helophorus (Lihelophorus) ser Zaitzev, 1908: 422 .

Helophorus (L.) ser : ANGUS (1995): 190 (redescription, lectotype designation); FIKÁČEK et al. (2012): 437 (phylogenetic analysis).

Type locality. China, Qinghai Province, valley of Alag Hu lake, 35.573°N, 97.120°E.

Type material examined (1 spec.). LECTOTYPE (designated by ANGUS 1995 ): 1 J ( ZIN): ‘LECTO- / TYPE [rounded label with violet margin] // Ю. cкл. xp. Буpxaн- Бyддa : [= Yu. skl. khr. Burkhan-Budda:] / дoл. oЗ. Aлык- Нop. [dol. oz.Alyk-Nor] 30.V.1900. / Эkcп. КoЗлoвa. [= Eksp. Kozlova.] // Hel. ( Lihelophorus ) / ser sp. n. / iv.08 Zaitzev det. // LECTOTYPE March 1970 / Helophorus ser Zaitz. / R. B.Angus det.// кoлл. Семенова- T.Ш. [koll. Semenova-T.Sh.]’ Additional material examined (95 spec.). CHINA: XIZANG: 1 J ( IRSNB): Apo Zo, Westtibet , Aug.1906, Zugmayer (identified as H. lamicola by Orchymont and Knisch) ; 1 unsexed spec. (BMNH): ‘ S. Tibet, vall. SE of Dongo La Pass [= valley SE of Dong La pass], 28°46ʹN, 87°57ʹE, 4900–5300 m’, 18.vi.2011, J. Schmidt lgt .; 16 JJ 16 ♀♀ (BMNH), 1 J 1 unsexed spec. ( NMPC): ‘S. Tibet E Nyainqentanglha Feng [Mt.], E slope Lha Tsu Vall [Lha Tsu valley], 5000–5350 m, 30°22′47″N 90°43′22″E’, 20.vii.2010, J. Schmidt lgt .; 1 ♀ ( NMPC): Pumo Tso to Monda La , 5000–5120 m, 28.vi.2015, 28°29′N 90°33′E, J. Schmidt lgt. [DNA voucher MF1248]. GANSU: 9 spec. ( NMPC):Xiahe (= Labrang) env., 35°11.5′N 102°30.6′E, 2940 m, 19.–22.vi.2005, J. Hájek, D. Král & J. Růžička lgt. QINGHAI: 4 spec. ( NMPC): Gangca Dasi (lamasery), 37°32.4–33.0′N 100°05.3–06.0′E, 3505–3840 m, 11–12.vi.2005, J. Hájek, D. Král & J.Růžička lgt .; 1 J 5 spec. ( NMPC): Haibu env., 3190–3270 m,36°48.4–49.8′N 100°45.4–49.7′E, 13–15.vii.2005, J. Hájek, D. Král & J. Růžička lgt .; 1 J 3 spec. ( NMPC): Hairag , 3240 m, 37°10.1′N 100°24.7′E, 3–5.vii.2005, J. Hájek, D. Král & J. Růžička lgt .; 1 J (BMNH): Golo, Maduo , roadside pools on river flats 20 km E of Maduo. 34°51′17″N, 98°17′18″E, 4290 m, 8.vi.2013, R. B. Angus, F. L. Jia & Y. Zhang lgt .; 2 JJ 6 ♀♀ (BMNH): Golo, Huamuxia, Zuimatan , roadside pool, 35°19′52″N, 99°03′57″E, 4141 m, 7.vi.2013, R. B. Angus, F. L. Jia & Y. Zhang lgt .; 3 JJ 2♀♀, 6 unsexed spec. ( SYSU): same label data ; 2 spec. ( NMPC): same label data [DNA vouchers MF658 and MF659] ; 1 J, 2 unsexed spec. ( SYSU): Kekexili [= Kekesili], Kangzhagri , 5130 m, 15.viii.1990, Xuezhong Zhang lgt .; 2 JJ 1 ♀ ( SYSU): Kekexili, Xinqingfeng [= Syn Qing Feng, or Buka Daban Feng] Mt. hot spring, 4900 m, 2.viii.1990, Xuezhong Zhang lgt .; 1 J, 2 unsexed spec. ( SYSU): Kekexili, Malanshan , 4950 m, 1.viii.1990, Xuezhong Zhang lgt .; 1 J ( SYSU): Kekexili, Kusaihu lake , 4600 m, 10.viii.1990, Xuezhong Zhang lgt .; 1 J 1 ♀ ( SYSU): Golo, Maduo, roadside pools near Yematan , 34°40′47″N 99°03′57″E, 4240 m a.s.l., 8.vi.2013, R. B. Angus, F. L. Jia & Y. Zhang lgt. INDIA: JAMMU AND KASHMIR: 1 ♀ ( IRSNB): Indian Tibet, L 73 Chushol, pond below village, 10.viii.1932 (identified as H. ser by Orchymont) .

Differential diagnosis. Characterized by moderately wide pronotum with distinctly sinuate sides abruptly narrowed just before anterior corners, with five longitudinal grooves distinctly impressed ( Figs 2c–d , 3a–g , 4d–h ); in this it is more similar to H. yangae sp. nov. (which differs by aedeagus with rounded parameral apices) than to H. lamicola . Elytral series, including the scutellary stria, are always very distinct (in contrast to H. lamicola ). Meso- and metatarsal claws are long (as in H. lamicola , but unlike H. yangae sp. nov.). Metatarsomere 5 is usually longer (often much longer) than metatarsomeres 3–4 combined. The aedeagus is very similar to H. lamicola (based on pointed parameral apices) but the median lobe in narrower and its apical portion longer ( Figs 6a–e ). For detailed comparison see Table 2.

Redescription. Body length: 4.4–5.7 mm in males, 4.9–6.1 mm in females.

Head. Dull bronze with green to purple reflections to completely black, closely and irregularly punctate, giving a rough effect in some portions, punctation consisting of two sizes of punctures. Y-groove shallow to moderately deep, with rather distinct stem wider than lateral arms, widened anteriorly. Maxillary palpi pale yellow, elongate, apical segment asymmetrical. Antennae yellow, 9-segmented. Maxillary galea in shape of simple pubescent lobe, without strong spines ( Fig. 1d ). Mandible rather short, with simple blunt apex ( Fig. 1f ).

Pronotum. Yellow, wider than the head, moderately and evenly arched. Widest closely before anterior corners; sides strongly arcuate, abruptly narrowed anteriorly, straight to indistinctly sinuate posteriorly. Grooves distinct, usually deeply and sharply impressed; mid groove straight, narrow; submedian grooves slightly sinuate; submarginal grooves with their basal pits distinct, bent mesally in anterior fourth. Narrow raised lateral margin distinct. Intervals without granules but with large punctures and smaller ones between them.

Elytra. Yellow as pronotum, with or without apparent darker sutural Λ- mark and sublateral spots. Striae distinct, consisting of rather large punctures, scutellary stria always distinct. Interval punctures much smaller than the striae, with fine erect hairs. All intervals flat, including the 10 th.

Legs. Long, with long swimming-hairs on meso- and metatibiae and meso- and metatarsi; metatarsomere 5 distinctly longer than metatarsomeres 3–4 combined; metatarsal claw ca. 0.5× as long as utimate metatarsomere.

Aedeagus. Parameres pointed, very weakly to strongly sinuate on outer margin. Phallobase ca. as long as or slightly shorther than parameres. Median lobe narrow, its distal portion long (in shape of more less equilateral triangle); base of median lobe (between the struts) arcuate, with median backwardly directed spur.

Variation. The species varies considerably in size and body proportions; both smaller narrower ( Fig. 3e ) and larger wide ( Figs 3d, g ) specimens are known. Coloration also varies slightly, especially as it concerns the colouration of the head ( Figs 4d–h ) and the absence / presence of the dark patterns on elytra; elytra of the specimens from high altitudes of southern Xizang (collected by J. Schmidt) are often slightly darker than in other examined specimens ( Fig. 3f ). The pronotum varies slightly in the shape of the sides as well as in the depth and shape of the pronotal grooves ( Figs 4d–h ), with rare specimens with partly reduced shallow grooves ( Fig. 4e ) which may resemble H. lamicola . The aedeagus varies considerably in the shape of the apical portions of parameres: the variation is the same as in H. lamicola , see there for details. In addition to that, we observed the considerable variation in the length of the aedeagus (compare Figs 6a–c and 6d–e ) which was not found in H. lamicola . Examined specimens with shorter aedeagus were mostly from southern Xizang (specimens collected by J. Schmidt, Figs 6b–c ), but the lectotype from central Qinghai also has this kind of the aedeagus; on the other hand, most specimens examined from Qinghai and Gansu have longer aedeagus ( Figs 6d–e ). The apparent paler coloration of the aedeagus of the lectotype and specimens collected by J. Schmidt ( Figs 6a–c ) may be an artefact of long-term storage of the specimens in fixation fluid.

Distribution (Fig. 7a). Very widely distributed on the Tibetan Plateau, from Indian province Jammu and Kashmir to southern Gansu in China. It occurs at altitudes ranging from 2940 m (Gansu: Labrang) to ca. 5350 m (Xizang: Nyainqentanglha Feng). As pointed out by Joachim Schmidt (pers. comm. to R. B. Angus) this makes it one of the highest-living of all Coleoptera . Note. The record of H. ser from Indian Tibet by ORCHYMONT (1943) was based on a misidentified specimen of H. yangae (see under that species for details).

Helophorus (Lihelophorus) yangae Angus, Fiká č ek & Jia, sp. nov. ( Figs 1a–c, e, h ; 2a–b, g ; 3h–k ; 5a–e ; 6j–n )

Type locality. China, Qinghai Province. Zuimatan, Roadside pool, 35.333°N 99.007°E.

Type material (143 spec.): HOLOTYPE: J ( SYSU): ‘CHINA QINGHAI Golo, Huamuxia, Zuimatan , Roadside pool, 35°19′52”N 99°03′57”E, 4141m, 7.vi.2013, R.B.Angus, F.L.Jia & Y. Zhang lgt .’ PARATYPES: CHINA: QINGHAI: 2 JJ 2 ♀♀ (BMNH): same data as the holotype [1 J: chromosome prep. 3, 12.vi.2013, R.B. Angus; 1 J: chromosome prep. 1, 13.vi.2013, R.B. Angus] ; 2 JJ 1 ♀ ( SYSU): same data as the holotype ; 1 J 2 ♀♀ (BMNH): Golo, Maduo, roadside pools near Yematan , 34°40′47″N 99°03′57″E, 4240 m, 8.vi.2013, R. B. Angus, F. L. Jia & Y. Zhang lgt. [J: chromosome prep. 2, 10.vi.2013, R. B. Angus] ; 6 JJ 9 ♀♀ ( SYSU): same label data ; 2 ♀♀ ( NMPC): same label data [DNA vouchers MF662 and MF664] ; 3 JJ 2 ♀♀ ( SYSU): Golo, Maduo, Heihexiang , roadside pools near Xingxinghai lake 34°40′47″N 99°03′57″E, 4240 m a.s.l., 8.vi.2013, R. B. Angus, F. L. Jia & Y. Zhang lgt ; 1 female (BMNH): Golo, Maduo , roadside pools on river flats 20 km E of Maduo. 34°51′17″N, 98°17′18″E, 4290 m, 8.vi.2013, R. B. Angus, F. L. Jia & Y. Zhang lgt .; 1 ♀ (BMNH): N. Qinghai Hu, Gangca , roadside pool. 37°18′N, 100°11′E, 3370 m, 5.vi.2013, F. L. Jia & Y. Zhang lgt. [chromosome prep. 2, 12.vi.2013, R. B. Angus]. XIZANG: 3 JJ 4 unsexed spec. ( SYSU):suburb of Rikaze, 3826 m, 20–23.vii.1986, Liang Ge-Qiu lgt .; 1 unsexed spec.( SYSU): Jiangzi , 27–28.vii.1986, Liang Ge-Qiu lgt .; 3 JJ 3 ♀♀, 19 unsexed spec. ( SYSU): Dangxiong, Yangbajing town , 4320 m a.s.l., 6.viii.2013, 30°5′43.18″N, 90°32′21.33″E, Jia Yue & Jia Fenglong lgt .; 2 JJ 3 ♀♀ 8 unsexed spec. ( SYSU): Nanshan, Zhanang County, Sangye Fery , 29°19′23.12″N, 91°30′33.79″E, 3658 m a.s.l., 2.viii.2013, Jia Yue & Jia Fenglong lgt .; 2 JJ 2 ♀♀ 6 unsexed spec. ( SYSU): Nanshan, Zhanang County, near Sangye temple, 29°19′25.49″N, 91°30′13.42″E, 3575 m a.s.l., 6.viii.2013, Jia Yue & Jia Fenglong lgt .; 2 JJ 2 ♀♀ 9 unsexed spec. ( SYSU): Shannan, Zhanang County, Sangye town , 29°19′23.12″N, 91°30′33.79″E, 3620 m a.s.l. Jia Yue & Jia Fenglong lgt .; 1 J ( SYSU): Shannan, Langkazi , 28°58′4.91″N, 90°23′52.72″E, 5030 m a.s.l., 5.viii.2013, Jia Yue & Jia Fenglong lgt .; 2 JJ 2 ♀♀, 7 unsexed spec. ( SYSU): near Yangzhuoyongcuo lake , 28°54′57.55″N, 90°43′29.18″E, 4447 m a.s.l., 3.viii.2013, Jia Fenglong & Jia Yue lgt .; 1 J ( SYSU): Gongbujiangda , 29°53′7.01″N, 93°14′45.88″E, 4155 m a.s.l., 2.viii.2013, Jia Fenglong & Jia Yue lgt .; 4 JJ 2 ♀♀ 15 unsexed spec. ( SYSU): Rikaze, Jiamudui village , 29°9′11.57″N, 89°0′40.67″E, 3872 m a.s.l., 2.viii.2013, Jia Yue lgt ; 1 J 3 ♀♀ ( NHMW): ‘CHINA: Tibet 9.VIII. / 90 km W Amdo / Cigetang 4400m / leg. X. Guo 1998 ’; 1 ♀ ( NHMW): ‘CHINA: Tibet 14.VIII. / 25 km W Amdo, 4400m / Couna Lake – brook / leg. X. Guo 1998’. INDIA: JAMMU AND KASHMIR: 1 J ( IRSNB): ‘male symbol // Indian Tibet / Tzo-Kar [= Kar Tso] Sta- / ktsak-Puk-tso [= Startsakpuk Tso] / pool in swamp / 4-IX, 1932 // A. d’Orchymont det. / H. ( Lihelophorus ) / ser Zaitzev’ .

Differential diagnosis. Distinguished from the other two Lihelophorus species ( H. lamicola and H. ser ) by the rather wide evenly arched pronotum (width approximately equal to length of mesotarsus + claw) with rounded sides and narrow marginal grooves, rather short metatarsal claws and by the bluntly rounded apices of the parameres. For detailed comparison see Table 2. Description. Body length: 4.6–5.1 mm in males, 5.0– 6.1 mm in females.

Head. Greenish bronze to maroon bronze, surface with flattened granulation, the granules with large median pits and the grooves between the granules sometimes interrupted resulting in partial coalescence of the granules. Y-groove with the stem at least twice as wide as the arms, widened anteriorly, its floor rugulose. Maxillary palpi yellow, elongate, the apical segment asymmetrical, darkened towards the tip. Antennae with 9 antennomeres, yellow, the clubs a little darker. Maxillary galea angulate apically, with several stout setae ( Fig. 1c ). Mandible wide, apex bifid ( Fig. 1e ).

Pronotum. Yellow, grooves sometimes slightly darker. Moderately and very evenly arched, widest medially, the sides evenly curved. Grooves narrow and shallow, sometimes weaker over anterior fifth of the pronotum; submedian grooves weakly angled outwards medially, occasionally interrupted in the region of the angle; marginal grooves rather indistinct, not obviously widened medially. Intervals punctate, sometimes very finely so; surface between the punctures either smooth or rugulose.

Elytra. Yellow to dirty yellow with vague darker mottling, the brownish sutural Λ- mark absent or distinct. Striae present as rows of punctures, very weakly impressed below the level of the interstices. All interstices, including the outermost one, completely flat. Scutellary stria with 5–8 punctures. Elytra widest just behind middle, tapering to blunt apex, the sides gently rounded.

Legs. Yellow with apical tarsal segment dark brown apically, and claws brown. Legs rather long, with long swimming-hairs on meso- and metatibiae and meso- and metatarsi;

metatarsomere 5 distinctly ca. as long as metatarsomeres 3–4 combined; metatarsal claw ca. 0.4× as long as ultimate metatarsomere.

Aedeagus. Parameres bluntly rounded apically, weakly sinuate on outer margin. Phallobase ca. as long as parameres. Median lobe wide, its distal portion short (in shape of more less isosceles triangle); base of median lobe (between the struts) straight, with median backwardly directed spur.

Variation. The species varies slightly in size and body proportions, both smaller narrower ( Fig. 3j ) and larger wider ( Fig. 3i ) are known. Coloration varies slightly as well, both in coloration of the head (black or with weak greenish to purple sheen) and the elytra (from yellowish to brown, sutural Λ- mark present or absent). Pronotum varies slightly in the extent of the impression of the grooves as well as in their shape, in rare specimens the submedian grooves may be even Y-shaped anteriorly ( Fig. 5d ). Aedeagus varies slightly in the proportions of the median lobe, but otherwise its morphology is very constant in all specimens examined.

Etymology. This species is named after Dr Xiaomei Yang, wife of Fenglong Jia.

Distribution (Fig. 7a). Widely distributed on the Tibetan Plateau, at altitudes ranging from 3300 m (Gangca) to ca. 5000 m (Langkazi).

Immature stages

Figures

Fig. 1. Adult morphology of Helophorus (Lihelophorus). a–b – H. yangae sp. nov. (a – ventral view of the head; b – detail of mentum and labial palps); c–d – maxillary galea and lacinia (c – H. yangae sp. nov.; d – H. ser Zaitzev, 1908); e–f – mandible (e – H. yangae sp. nov.; f – H. ser); g – labial palpus of H. ser; h–l – hind legs in dorsal view (h – H. yangae sp. nov.; i – H. ser; j – H. lamicola Zaitzev, 1908; k – detail of apex of tibia and base of tarsus of H. lamicola; l – detail of tarsomere 5 and claw of H. ser). Abbreviations: sh – swimming hairs. Not to scale.

Fig. 2. Adult morphology of Helophorus (Lihelophorus). a–f – details of left half of pronotum (a,c,e) and base of left elytron (b, d, f): a–b – H. yangae sp. nov.; c–d – H. ser Zaitzev, 1908; e–f – H. lamicola Zaitzev, 1908; arrow in (a) shows remnants of pronotal granulations, arrows in (b, d, f) show scutellary stria. g–h – prothoracic hypomeron and ‘suprapleural area’ (g – H. yangae sp. nov.; h – H. ser). i – detail of posterior margin of abdominal ventrite 5 of H. ser, showing the irregular denticulation. j – ventral view of the thorax of H. ser. k – dorsolateral portion of left elytron of H. lamicola. Abbreviations: ep – epipleuron; li – last elytral interval. Not to scale.

Fig. 3. Habitus of the species of Helophorus (Lihelophorus). a–c – H. lamicola Zaitzev, 1908 (a – Qinghai: Zhaling Hu (lectotype); b–c – Quinghai: Golo).d–g – H.ser Zaitzev, 1908 (d–e – Qinghai:Golo; f – Xizang, Nyainqentanglha Feng; g – Gansu: Xiahe env.). h–k – H. yangae sp. nov. (h – Xizang: 90 km W of Amdo; i – Xizang: 25 km W of Amdo; j – Qinghai: Golo; k – India: Kar Tso (Orchymont coll.)). All specimens to scale.

Fig.4. Details of the head and pronotum of the Helophorus (Lihelophorus) specimens.a–c – H. lamicola Zaitzev,1908 (a – Qinghai: Zhaling Hu (lectotype); b–c – Qinghai: Golo). d–h – H. ser Zaitzev, 1908 (d – Qinghai: valley of Alag Hu lake (lectotype); e–f – Qinghai: Golo; g – Xizang, Nyainqentanglha Feng; h – Gansu: Xiahe env.). Not to scale.

Fig. 6.Aedeagophores of Helophorus (Lihelophorus) species. a–e – H. (L.) ser Zaitzev, 1908 (a – lectotype, Qinghai: valley of Alag Hu lake; b–c – Xizang: valley SE of Dong La pass; d – Qinghai: Golo, 20 km E of Maduo; e – Qinghai: Zuimatan). f–j – H. (L.) lamicola Zaitzev, 1908 (f – lectotype, Qinghai: Djarin Nor; g–i – Qinghai: Zuimatan; j – paralectotype, Xizang: S of Arka-tagh, 5073 m a.s.l., lgt. S. Hedin). k–o – H. (L.) yangae sp. nov. (k – holotype, Qinghai: Zuimatan; l–m – paratypes, same locality; n – Qinghai: Golo, Yematan; o – Xizang: Gongbujiangda).

Fig. 5. Details of the head and pronotum of the Helophorus (Lihelophorus) yangae sp. nov. (a – Xizang: 90 km W of Amdo; b,d – Qinghai: Golo; c – Xizang: 25 km W of Amdo; e – India: Kar Tso (Orchymont coll.). Not to scale.