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 nakamurai Guéorguiev, 1970 Source of material. The two instar II and five instar III larvae studied were reared ex ovo from adults collected at the following locality: Japan . Kasamatshu-cho , Mudoji , Gifu Prefecture , 4.V.2018 . Y. Yoshimura , leg. Diagnosis (instar III). The third instar of Copelatus nakamurai 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 < 0.40 mm ; head capsule subquadrate, strongly constricted at level of occipital region ( Fig. 28 ), scale-like sculpticels lacking over frontoclypeus, present over parietale; anterior margin of frontoclypeus narrowly convex, extending mesally well beyond adnasalia ( Fig. 28 ); adnasalia margined with elongate acute 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 one urogomphomere; U/HW <0.40; U/LAS <0.50; Palaearctic. Description, instar II Body: Measurements and ratios aimed to characterize body shape are shown in Table 4 . Head: Head capsule subquadrate, strongly constricted at level of occiput; anterior margin of frontoclypeus narrowly convex, extending well beyond level of adnasalia; scale-like sculpticels lacking over frontoclypeus, welldeveloped over parietale; adnasalia margined with elongate acute teeth (see Fig. 64 ); HL = 0.61 mm ; A/MP = 1.49; MP/LP = 2.06; MP2/MP1 = 1.60; GA/MP1 = 1.91; LP2/LP1 = 2.24; MNL/MNW = 3.11. Thorax: L3 = 1.23 mm . Abdomen: LAS = 0.45 mm ; LAS subcylindrical, slightly constricted posteriorly at point of insertion of urogomphi. Urogomphus: U = 0.26 mm , composed of one urogomphomere; U/HW = 0.41; U/LAS = 0.58. Chaetotaxy: Parietale with 8 temporal spines; position and number of secondary setae on legs are shown in Table 5 . Description, instar III ( Figs 28–29 , 64 ). As second-instar larva except as follows: Body: Measurements and ratios aimed to characterize body shape are shown in Table 6 . Head ( Figs 28 , 64 ): HL = 0.81–0.84 mm ; A/MP = 1.42–1.46; MP/LP = 2.02–2.25; MP2/MP1 = 1.51–1.74; GA/MP1 = 1.75–1.99; LP2/LP1 = 1.55–1.78; MNL/MNW = 2.85–2.98. Thorax: L3 = 1.66–1.72 mm . Abdomen ( Fig 29 ): LAS = 0.66–0.69 mm ; Urogomphus, U = 0.31–0.33 mm , composed of one urogomphomere; U/HW = 0.35–0.38; U/LAS = 0.45–0.49. Chaetotaxy: Parietale with 9–10 temporal spines; position and number of secondary setae on legs are shown in Table 7 .