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 : 137-138

Helophorus (Lihelophorus) lamicola

Larval material examined (5 larvae). 1 first instar larva ( NMPC, DNA voucher MF660 ): CHINA: QINGHAI: 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 .; 4 first instar larvae (BMNH): same label data. All larvae were reared from the single egg case (deposited in BMNH) laid by a field-collected female, association with adults from the same locality was confirmed by the cox1 sequence data .

Egg case ( Fig. 8e ). Consisting of an egg-bag surmounted by a thin trailing mast which takes the form of a long narrow tube, thus corresponding to Type 4 egg case of ANGUS (1992). The egg case was placed in the sand at the water’s edge in the aquarium housing the beetles, and has sand grains adhering to the egg-bag. A similar egg case was observed in the ground at the water’s edge in the Zuimatan locality where the beetles were collected

Larva. General morphology (only characters different from H. yangae are mentioned). Body ( Fig. 9c ) elongate, slender, almost parallel-sided. Body length ca. 2.9 mm. Head width 0.43–0.46 mm (n = 5). Parietale ( Figs 12a–b ) with numerous cuticular spines dorsally and laterally, ventral face smooth. Frontoclypeus ( Fig. 12e ) with large bulged asymmetrical nasale bearing single median tooth, and large slightly asymmetrical epistomal lobes overlapping nasale. Gular suture absent, posterior tentorial pits minute, situated anteromesally ( Figs 8a–b ). Mandibles ( Figs 13c–d ) slightly asymmetrical, with falcate apical portion. Retinaculum with two teeth; distal tooth large, bearing dense tuft of long cuticular spines; basal tooth small, with numerous cuticular spines in left mandible and few projections in right one. Basal inner face projecting into a small lobe, with a basal field of fine spine-like cuticular projections. Maxilla ( Figs 14e–f ). Stipes ca. as long as palpifer, sinuate laterally, mesal face with a series of irregular cuticular spines, lateral face with small blunt cuticular spines; palpifer slightly longer than stipes. Labium ( Figs 13i–j ). Submentum completely fused with parietale, submental suture absent. Mentum without cuticular spines on dorsal surface. Thorax. Legs ( Fig. 15d ) very long, 5-segmented; trochanter ca. half as long as femur; tibiotarsus cylindrical, slightly longer than trochanter and femur combined. Claw ca. as long as tibiotarsus, slightly bent ventrad. Abdomen (8g –h, 15h). Segments 1–8 each with a pair of long finger-like projections laterally below spiracles, bearing lateral sclerite on apex; each projection with trachea connected to tracheal branch connecting main tracheal trunk with spiracle lying above base of the particular projection.

Chaetotaxy. Head. Frontal pores FR2 closer to each other than setae FR3; setae FR8 widely separated from each other; parietal setae PA7, PA12, and PA14 much longer than in L. yangae . Labial setae LA3 very long. Maxillary setae MX 5 and MX 6 of the same length, both rather long; setae MX 8–11 very long, situated along the whole length of stipes; apical maxillary palpomere with multiple additional digitiform sensilla. Abdomen with lateral abdominal sclerite (situated on the top of tracheal gill) with three setae.

Figures

Fig. 8. Immature stages of Lihelophorus. a–d – head and prothorax of first instar larvae: a–b – H. (Lihelophorus) lamicola Zaitzev, 1908 (a – dorsal; b – ventral); c–d – H. (Lihelophorus) yangae sp. nov. (c – dorsal; d – ventral). e–f – egg cases: e – H. (Lihelophorus) lamicola Zaitzev, 1908; f – H. (Lihelophorus) yangae sp. nov.; g–j – abdomen with spiracles containing air bubbles: g–h – H. (Lihelophorus) lamicola Zaitzev, 1908 (g – tracheal gills and its tracheal system; h – detail of tracheal branching around abdominal spiracle); i–j – H. (Lihelophorus) yangae sp. nov. (i – detail of tracheal system around abdominal spiracles; j – tracheal system of abdomen). Abbreviations: sp – spiracle; trg – tracheal gill.

Fig.9.Association of reared larvae andfield-collected adults of Helophorus (Lihelophorus) based on cox1 sequences. a – Bayesian inference of newly obtained and available GenBank sequences; b–c – habitus of reared larvae (b – H. yangae sp. nov.; c – H. lamicola Zaitzev, 1908).

Fig. 12. Labroclypeus and epistome of larvae of Lihelophorus and Helophorus s.str. a–b – H. (H.) liguricus Angus, 1970 (a – dorsal view; b – ventral view); c–d – H. (Lihelophorus) yangae sp. nov. (c – dorsal; d – ventral); e–f – H. (Lihelophorus) lamicola Zaitzev, 1908 (e – dorsal; f – ventral).

Fig. 13. Head appendages of larvae of Lihelophorus and Helophorus s.str. a–d – mandibles in dorsal view: a – H. (H.) liguricus Angus, 1970 (left mandible); b – H. (Lihelophorus) yangae sp. nov. (left mandible); c–d – H. (Lihelophorus) lamicola Zaitzev, 1908 (c – left mandible; d – right mandible). e–f – left antenna in dorsal view: e – H. (H.) liguricus Angus, 1970; f – H. (Lihelophorus) yangae sp. nov. g–j – labium: g–h – H. (Lihelophorus) yangae sp. nov. (g – ventral; h – dorsal); i–j – H. (Lihelophorus) lamicola Zaitzev, 1908 (i – ventral; j – dorsal).Abbreviations: mp – mandibular penicillus; rt – retinacular tuft.

Fig. 14. Head appendages of larvae of Lihelophorus and Helophorus s.str. a–b – labium of H. (H.) liguricus Angus, 1970 (a – ventral; b – dorsal). c–h – maxilla: a–d – H. (H.) liguricus (c – ventral; d – dorsal); e–f – H. (Lihelophorus) yangae sp. nov. (e – ventral; f – dorsal); g–h – H. (Lihelophorus) lamicola Zaitzev, 1908 (g – ventral; h – dorsal).

Fig. 15. Thorax and abdomen of Lihelophorus and Helophorus s.str. a–d – metathoracic legs (a – H. (H.) liguricus Angus, 1970, frontal view; b–c – H. (Lihelophorus) yangae sp. nov.(b – frontal; c – posterior); d – H. (Lihelophorus) lamicola Zaitzev, 1908). e–f – thorax and first abdominal segments of H. (Lihelophorus) yangae sp. nov. (e – lateral view; f – dorsal view). g–h – abdominal segments (dorsal and ventral views): g – H. (Lihelophorus) yangae sp. nov.; h – H. (Lihelophorus) lamicola Zaitzev, 1908. i–j – abdominal segment 9 and urogomphi: i – H. (H.) liguricus Angus, 1970; j – H. (Lihelophorus) yangae sp. nov.Abbreviations:abd1 – abdominal segment 1; msth – mesothorax; mtth – metathorax; pth – prothorax; sp – spiracle.