Helophorus (Lihelophorus) lamicola 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 : 117-118

Helophorus (Lihelophorus) lamicola Zaitzev, 1908

( Figs 1j–k ; 2e–f, k ; 3a–c ; 4a–c ; 6f–i )

Helophorus (Lihelophorus) lamicola Zaitzev, 1908: 421 . Helophorus (L.) lamicola : ANGUS (1995): 189 (redescription, lectotype designation).

Type locality. China, Qinghai Province, Zhaling Hu (Lake) (= Djarin Nor), 34.911°N 97.273°E.

Type material examined (3 spec.). LECTOTYPE (designated by ANGUS 1995: 189): 1 J ( ZIN): ‘LECTO- / TYPE [rounded label with violet margin] // Дoл. оЗер верхн. Хуан- хе: [= Dol. ozer verkhn. Khuan-khe] / oЗ. Джарин- -нор. [= oz. Dzharin-nor. ] / Кон. [= Kon. ] VI. 1900. / Эkcп. КoЗлoвa. [= Eksp. Kozlova.] // LECTOTYPE March 1970 / Helophorus lamicola / Zaitz. / R. B. Angus det. // coll. Zaitzev’ . PARALECTOTYPES: 1 damaged specimen with dissected mouthparts, 1 ♀ ( ZIN): ‘PARA- / LECTO- / TYPE [rounded label with blue margin] // Дoл. оЗер верхн. Хуан- хе: / oЗ. Джарин- нор. / Кон. VI. 1900. / Эkcп. КoЗлoвa. // March 1970 / Paralectotype. / H. lamicola Zaitzev / R. B. Angus det. // coll. Zaitzev’ ; 1 J ( NHRS): ‘ Vatten djur [= water animal] / 25 Juni [19]01 / L. XXIII [= camp XXIII] / Hedin // Hel. ( Lihelophorus ) / lamicola m. / III. 08 Zaitzev det. / 8248 // NHRS-JKLB /000021180 // 3817 / E91”. Based on ORCHYMONT (1943) who studied Sven Hedinʼs journal, camp 23 was situated south of Arka-tagh at altitude of 5073 m a.s.l., at approximate GPS coordinates 36°16ʹN, 88°21′E .

Additional material examined (9 spec.). CHINA: QINGHAI: 1 ♀ (BMNH): same label data as the lectotype, but from Semenov collection and without type labels ; 3 JJ 1 ♀ (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 .; 1 J ( SYSU): same label data; 2 spec. ( NMPC): same label data [DNA vouchers MF661 and MF662] ; 1 ♀ ( NMPC): road to Tuotuohe , 4500 m, 35°21′53″N 93°26′28″E, 22.vii.2015, J. Schmidt lgt. [DNA voucher MF1247] .

Differential diagnosis. Differs from other Lihelophorus by narrow pronotum (maximum width clearly less than length of mesotarsus + claw) with rather straight sides and almost entirely effaced pronotal grooves ( Figs 2e , 3a–c , 4a–c ). In contrast to other Lihelophorus , elytral series are often not impressed basally, punctures of elytral series are small and interval punctures very small; because of that, the scutellary stria is sometimes rather indistinct. Meso- and metatarsal claws are long (as in H. ser , but unlike H. yangae sp. nov.). The aedeagus is very similar to that of H. ser (based on pointed parameral apices) but the median lobe is wider and the apical portion shorter ( Figs 6f–i ). For detailed comparison see Table 2.

Redescription. Body length: 5.1–5.5 mm in males, 5.2–6.1 mm in females.

Head. Dull brownish bronze with green reflections, closely and irregularly punctate, the punctures not round, giving a generally rough effect. Y-groove shallow, its stem rather indistinct, wider than the 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 (as in Fig. 1d ). Mandible rather short, with simple blunt apex (as in Fig. 1f ).

Pronotum. Yellow, a little wider than the head, moderately and evenly arched, widest before the middle, sides weakly curved to base. Anterior angles sharper and more pronounced than is usual in Helophorus . Grooves scarcely traceable, mid groove straight, narrow; submedian grooves angled outwards medially, petering out anteriorly but sinuate a quarter of the way from each end; submarginal grooves with their basal pits distinct, traceable forward from these, petering out at middle of pronotum. Narrow raised lateral margin distinct. Intervals without granules but with large punctures and smaller ones between them.

Elytra. Yellow, as pronotum, without apparent darker marks, slightly dull. Striae weak and shallow, scutellary stria present but often rather indistinct due to small size of serial punctures. Interval punctures only slightly 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 ca. as long as metatarsomeres 3–4 combined; metatarsal claw ca. 0.65× 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 wide, its distal portion short (in shape of more less isosceles triangle); base of median lobe (between the struts) rather straight but with median backwardly directed spur.

Variation. The species varies considerably in size and body proportions, i.e. both smaller narrower ( Fig. 3b ) and larger wide ( Fig. 3c ) are known. The shape of the sides of the pronotum varies slightly from weakly arcuate ( Fig. 4a ) to indistinctly sinuate ( Figs 4c ). The aedeagus varies considerably in the shape of the apical portions of parameres; they may be narrow with lateral margin indistinctly sinuate ( Figs 6f–g ) or apically widely expanded with lateral margin strongly sinuate ( Figs 6h–i ); the proportion of the phallobase to parameres varies slightly, but no specimens with extremely long phallobase were found; the width of the apical portion of the median lobe varies from very wide ( Figs 6g –h ) to rather narrow ( Figs 6f, i ). The apparent paler coloration of the aedeagus of the lectotype ( Fig. 6f ) in comparison to other specimens examined ( Figs 6g –i ) is very likely caused by the fact that the lectotype is slightly teneral.

Distribution (Fig. 7a). Confined to the northern part of the Tibetan Plateau, from Zuimatan in the east, via Lake Zhaling Hu (type locality) to Sven Hedin’s camp 23, situated south of the Arka-tagh mountains. The altitudes of the localities range from about 4140 to 5070 m a.s.l.

Note. The record of H. lamicola from Apo Tso by ORCHYMONT (1943) was based on a misidentified specimen of H. ser (see under that species for details).

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).