An outlook on larval morphology of Copelatinae diving beetles with phylogenetic considerations (Coleoptera: Adephaga, Dytiscidae) Author Alarie, Yves Department of Biology, Laurentian University, Ramsey Lake Road, Sudbury, Ontario, P 3 E 2 C 6, Canada Author Michat, Mariano C. 0000-0002-1962-7976 University of Buenos Aires, Faculty of Exact and Natural Sciences, Department of Biodiversity and Experimental and Applied Biology (IBBEA), Buenos Aires, Argentina. https: // orcid. org / 0000 - 0002 - 1962 - 7976 Author Watanabe, Kohei 0000-0002-8761-232X Ishikawa Insect Museum, Inu- 3, Yawata-machi, Hakusan-shi, 920 - 2113 Japan. https: // orcid. org / 0000 - 0002 - 8761 - 232 X Naturhistorisches Museum Wien, Burgring 7, 1010 Vienna, Austria. https: // orcid. org / 0000 - 0001 - 5034 - 7342 Author Shaverdo, Helena 0000-0001-5034-7342 Author Wang, Liang-Jong 0000-0001-5540-2021 Division of Forest Protection, Taiwan Forestry Research Institute, Taipei, Taiwan. https: // orcid. org / 0000 - 0001 - 5540 - 2021 Author Watts, Chris H. S. 0000-0003-3131-4259 South Australian Museum, North Terrace, Adelaide, SA 5000, Australia. https: // orcid. org / 0000 - 0003 - 3131 - 4259 text Zootaxa 2022 2022-08-16 5175 2 151 205 journal article 123002 10.11646/zootaxa.5175.2.1 86116a08-1bf6-48c3-b318-c54c8fd0928c 1175-5326 7003344 C4601ABE-4C6F-48BA-BA24-3339A44DC15C Copelatus oblitus Sharp, 1882 Source of material. The five instar II and five instar III larvae studied were reared ex ovo from adults collected at the following locality: Japan . Mantaburu, Yonaguni-cho, Yonaguni-jima Island, Okinawa Prefecture . 24°27’04.1”N 122°57’36.8”E , 13VI.2019 ; K. Watanabe leg. Diagnosis (instar III). The third instar of Copelatus oblitus can easily be distinguished from that of the other species studied in this paper by the following combination of characters: HL = 0.80 mm ; L3 <2.00 mm; U < 0.30 mm ; head capsule ovate, not constricted at level of occipital region ( Fig. 30 ), scale-like sculpticels present over frontoclypeus and parietale; anterior margin of frontoclypeus narrowly convex, extending mesally well below level of adnasalia ( Fig. 30 ); adnasalia margined with short bluntly rounded teeth ( Fig. 64 ); MP2/MP1> 1.50; GA/MP1> 1.50; 1.30 <LP2/LP1 <1.90; inner margin of stipes lacking a dorsal linear row of spinulae; profemur with less than 3 PV and 4 AV secondary setae; metafemur with less than 3 AV secondary setae; urogomphus composed of two urogomphomeres; U/HW <0.40; U/LAS <0.50; Oriental and Palaearctic. Description, instar II Body: Measurements and ratios aimed to characterize body shape are shown in Table 4 . Head: Head capsule ovate, not constricted at level of occiput; anterior margin of frontoclypeus narrowly convex, extending mesally below level of adnasalia; scale-like sculpticels present over frontoclypeus and parietale; adnasalia margined with short bluntly rounded teeth (see Fig. 64 ); HL = 0.55–0.58 mm ; A/MP = 1.39–1.51; MP/LP = 1.70–1.82; MP2/MP1 = 1.67–1.95; GA/MP1 = 1.85–2.32; LP2/LP1 = 1.56–1.89; MNL/MNW = 2.41–2.61. FIGURES 28–29. Copelatus nakamurai Guéorguiev, 1970 , instar III: (28) head capsule, dorsal aspect (scale-like microsculptures not represented); (29) abdominal segment VIII, dorsal aspect. Scale bars = 0.2 mm. Thorax: L3 = 1.10–1.13 mm . Abdomen: LAS = 0.37–0.39 mm ; LAS subconical, not constricted posteriorly at point of insertion of urogomphi. Urogomphus: U = 0.17–0.19 mm , composed of two urogomphomeres; U/HW = 0.26–0.29; U/LAS = 0.45–0.51. Chaetotaxy: Parietale with 3–5 temporal spines; position and number of secondary setae on legs are shown in Table 5 . Description, instar III ( Figs 30–33 , 64 ). As second-instar larva except as follows: Body: Measurements and ratios aimed to characterize body shape are shown in Table 6 . Head ( Figs 30 , 64 ): HL = 0.74–0.80 mm ; A/MP = 1.50–1.60; MP/LP = 1.65–1.82; MP2/MP1 = 1.44–1.67; GA/MP1 = 1.59–1.83; LP2/LP1 = 1.31–1.47; MNL/MNW = 2.40–2.60. Thorax ( Figs 32–33 ): L3 = 1.57–1.64 mm . Abdomen ( Fig 31 ): LAS = 0.54–0.60 mm ; U = 0.20–0.25 mm , U/HW = 0.22–0.27; U/LAS = 0.37–0.47. Chaetotaxy: Parietale with 3–4 temporal spines; position and number of secondary setae on legs are shown in Figs 32–33 and Table 7 .