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Yang, Guo-Hui, Orr, Albert G., Zhang, Hao-Miao (2022): Descriptions of the larvae of Huosoma Guan, Dumont, Yu, Han & Vierstraete 2013 from China (Odonata: Coenagrionidae). Zootaxa 5134 (3): 426-434, DOI: https://doi.org/10.11646/zootaxa.5134.3.6

Huosoma tinctipenne (McLachlan, 1894) (Figs 2b; 4a–m; 6; 7d–e) Material examined: 1♀, larva, 1.V.2019, Haicang Village, Jiuzhou Town, Yunlong County (25.30°N, 99.02°E, 2,550 m a.s.l.), Dali City, Yunnan Province, China, Guo-Hui Yang leg., 1♀, 1♂ larvae, 6.VI.2021, same locality, Guo-Hui Yang leg. 1♀ larva was successfully raised to emergence. Habitus: Generally similar to H. latiloba. Legs and wing sheaths relatively slightly longer (Figs 7d, e) and, caudal lamellae leaf shaped, longer and narrower than in H. latiloba. Head. Comparatively large, occipital lobes gently rounded, not bulbous in dorsal view; mouthparts (Figs 4a–i), fairly similar to H. latiloba but with relatively broader prementum, maximum breadth ca 0.78 length; length about four times wider than base; anterior margin more strongly projected as obtuse isosceles triangle, apex forming 105° angle (dorsal view), with fine marginal denticles; row of four long, strong setae sub-medially on upper side of prementum. Labial palp long and narrow, distinctly expanded apically, upper margin with six very long, strong setae set in raised tooth-like sockets (Figs 4b, c); movable hook short, incurved, only ca 1/2 length of longest palpal seta; palp terminating in broad securiform ‘comb’ separated by shallow notch from short ventral hook slightly exceeding margin of comb in length (Fig. 6). Thorax. Very similar to H. latiloba but legs longer; femur of hind leg reaching to hind margin of S4; outer wing sheaths reaching just beyond hind margin of S4, inner sheaths slightly shorter (Figs 7d–e). Abdomen. Very similar to H. latiloba but ovipositor of female extending only to end of S10 (Figs 4j–k). Caudal lamellae foliate, long and narrow, more than half length of abdomen (maximum length 3.5 times width of lateral lamella and 3.2 times width of median lamella (Figs 4l–m). Lateral lamellae white-tipped with short terminal filament, also present in median lamella but less developed. Measurements (mm). Larvae (N=3), body length (excluding caudal lamellae) 11.5–14; length of abdomen (excluding caudal lamellae) 7.5–8; maximum head width 2.8–2.9; length of hind femur 3.6–4; lateral caudal lamella 4.5–5. Biological notes. The larvae of H. tinctipenne were found in a small, heavily vegetated shallow pond in a brook at an elevation of approximately 2,550 m (Fig. 8b). Adults were often present breeding in the same pond (Fig. 7f). The flight season ranges from June to September., Published as part of Yang, Guo-Hui, Orr, Albert G. & Zhang, Hao-Miao, 2022, Descriptions of the larvae of Huosoma Guan, Dumont, Yu, Han & Vierstraete 2013 from China (Odonata: Coenagrionidae), pp. 426-434 in Zootaxa 5134 (3) on pages 429-431, DOI: 10.11646/zootaxa.5134.3.6, http://zenodo.org/record/6538329, {"references":["Brochard, C. & van der Ploeg, E. (2013) Description of the exuvia and larva of Pyrrhosoma elisabethae. Libellula, 32 (3), 159 - 174."]}

Huosoma latiloba (Yu, Yang & Bu, 2008) (Figs 1, 2a; 3a–n; 5; 7a) Material examined. 1♀, 2♂♂ larvae, 6.X.2020, Huadianba (25.54°N, 100.00°E, 2,920 m a.s.l.), XiZhou Town, Dali City, Yunnan Province, China, Guo-Hui Yang leg. Huadianba is on Mt Cangshan in Dali, Yunnan. There are many streams and pools in the surrounding mountains. 1♀ and 1♂ larvae were collected and successfully raised to emergence. Habitus: Body small (body length including caudal lamellae 15–18mm long), smooth and moderately stout, lacking distinct bands or marks, with broad paddle-shaped caudal lamellae (Figs 1, 7a). Males and females are very similar except for presence of an ovipositor in the latter. Head: Wider than long, maximum width 1.9–2.1 times length. Compound eyes black and prominent. Occiput light brown, with occipital lobes rounded but rather bulbous (Fig. 2a); antenna filiform, 7–segmented, length of successive antennal segments (mm): 0.10, 0.10, 0.25, 0.35, 0.25, 0.25, 0.3 (Fig. 3a). Labium ochreous, prementum basally narrow, anteriorly expanded strongly and nearly evenly; anterior margin strongly projected as obtuse isosceles triangle, apex forming 115° angle (dorsal view), with fine marginal denticles; prementum length about 4.1 times wider than base, maximum breadth 0.7 length; row of 3–4 long, strong setae sub-medially on upper side of prementum (N=3) (Figs 3b, c). Labial palp long and narrow, distinctly expanded apically, upper margin with eight very long, strong setae set in raised sockets (Fig. 3d); movable hook incurved, but only ca 3/5 length of longest palpal seta (Figs 3d, 5); palp terminating in broad securiform ‘comb’ separated by shallow notch from short ventral hook slightly exceeding margin of comb in length. Mandibles brown, teeth black blown, formula: L 1+234+50y ab R 12345 ab, molar crest absent both right and left mandibles, incisor teeth rounded, 2> 3> 5> 4> 1, additional tooth y on the right mandible (Figs 3e–h). Maxillae long, with dense long setae present on the distal one-thirds of its length (Figs 3i–j). Thorax. Brown, smooth without distinct bands or marks. Prothorax rectangular. Synthorax trapezoidal and elongate. Legs moderately long and slender, the femur of hind leg reaching to middle of S4. Wing cases parallel, outer wing cases reach to the hind margin of S4, inner cases a little shorter. Abdomen. Brown, smooth with black brown markings. Lateral spines absent. Ovipositor of female extending beyond the end of S10 (Figs 3k–l). Caudal lamellae half as long as abdomen, broadly paddle-shaped ending in a short white filament, especially on outer lamellae, margins with well separated low serrations; surface marked with irregular black blotches, especially visible near base. Maximum length:width ratio 2.6 in lateral lamellae and 2.4 in median lamella (Figs 3m –n). Measurements (mm). Larvae (N=3), body length (excluding caudal lamellae) 12–13.5; length of abdomen (excluding caudal lamellae) 8–9; maximum head width 2.5–2.8; length of hind femur 3.5–4; lateral caudal lamella 4.5–5. Biological notes. The larva of H. latiloba was found in a pool in a small mountain stream, with numerous hydrophytes (Fig. 7a). Breeding adults often appear at the edge of nearby streams (Fig. 6c). The flight season ranges from June to September., Published as part of Yang, Guo-Hui, Orr, Albert G. & Zhang, Hao-Miao, 2022, Descriptions of the larvae of Huosoma Guan, Dumont, Yu, Han & Vierstraete 2013 from China (Odonata: Coenagrionidae), pp. 426-434 in Zootaxa 5134 (3) on pages 427-428, DOI: 10.11646/zootaxa.5134.3.6, http://zenodo.org/record/6538329