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 caelatipennis princeps Young, 1963 Source of material. The two larvae studied (one instar II and one instar III) were associated with adults collected at the following locality: USA . Florida , Orlando. Junction International Drive & Hwy 523, 26–28.IX.2016 . 28°53.83’N 81°37.92’W ; Y. Alarie leg. The identification is firm as C. caelatipennis princeps is the only Copelatus species known from that locality. Diagnosis (instar III). The third instar of Copelatus c. princeps 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 rounded to subquadrate, strongly constricted at level of occipital region ( Fig. 17 ), scale-like sculpticels present over frontoclypeus and parietale; anterior margin of frontoclypeus narrowly convex, extending mesally well beyond level of adnasalia ( Fig. 17 ); adnasalia margined with short bluntly rounded and truncated teeth ( Fig. 63 ); 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; Nearctic and Neotropical. Description, instar II Body: Measurements and ratios aimed to characterize body shape are shown in Table 4 . Head: Head capsule rounded to subquadrate, strongly constricted at level of occiput; anterior margin of frontoclypeus narrowly convex, extending well beyond level of adnasalia; adnasalia margined with short bluntly rounded and truncated teeth (see Fig. 63 ); scale-like sculpticels well-developed over frontoclypeus and parietale; HL = 0.58 mm ; A/MP = 1.41; MP/LP = 1.85; MP2/MP1 = 1.73; GA/MP1 = 2.00; LP2/LP1 = 1.73; MNL/MNW = 2.72. FIGURES 1–2. Copelatus alternatus Sharp, 1882 , head capsule, instar I: (1) dorsal aspect; (2) ventral aspect. EB, egg bursters; FR, frontoclypeus; LC, lamellae clypeales; PA, parietale; TP, tentorial pits. Numbers and lowercase letters refer to primary setae and pores, respectively. Scale-like sculptures not represented. Scale bar = 0.1 mm. FIGURES 3–5. Copelatus alternatus Sharp, 1882 , head appendages, instar I: (3–4) antenna; (3) dorsal aspect; (4) ventral aspect; (5) mandible, dorsal aspect. AN, antenna; MN, mandible; sp, spinula. Numbers and lowercase letters refer to primary setae and pores, respectively. Scale bars = 0.05 mm. FIGURES 6–9. Copelatus alternatus Sharp, 1882 , head appendages, instar I: (6–7) maxilla; (6) dorsal aspect; (7) ventral aspect; (8–9) labium; (8) dorsal aspect; (9) ventral aspect. LA, labium; MX, maxilla. Numbers and lowercase letters refer to primary setae and pores, respectively; * = additional sensilla. Scale bars = 0.05 mm. FIGURES 10–11. Copelatus alternatus Sharp, 1882 , metathoracic leg, instar I: (10) anterior surface; (11) posterior surface. CO, coxa; FE, femur; PT, pretarsus; TA, tarsus; TI, tibia; TR, trochanter. Numbers and lowercase letters refer to primary setae and pores, respectively; * = additional sensilla. Scale bar = 0.05 mm. FIGURES 12–14. Copelatus alternatus Sharp, 1882 , instar I: (12–13) abdominal segment VIII; (12) dorsal aspect; (13) ventral aspect; (14) urogomphus, dorsal aspect. AB, abdominal segment VIII; UR, urogomphus. Numbers and lowercase letters refer to primary setae and pores, respectively. Spine-like spinulae on abdominal segment VIII not represented. Scale bars = 0.05 mm. FIGURES 15–16. Copelatus alternatus Sharp, 1882 , instar III: (15) head capsule, dorsal aspect (scale-like microsculptures not represented); (16) abdominal segment VIII, dorsal aspect. Scale bars = 0.2 mm. Thorax: L3 = 1.05 mm . Abdomen: LAS = 0.39 mm ; LAS subconical, not constricted posteriorly at point of insertion of urogomphi. Urogomphus: U = 0.22 mm , composed of one urogomphomere; U/HW = 0.38; U/LAS = 0.58. Chaetotaxy: Parietale with 7 temporal spines; position and number of secondary setae on legs are shown in Table 5 . Description, instar III ( Figs 17–18 , 63 ). As second-instar larva except as follows: Body: Measurements and ratios aimed to characterize body shape are shown in Table 6 . Head ( Figs 18 , 63 ): HL = 0.81 mm ; A/MP = 1.50; MP/LP = 1.98; MP2/MP1 = 1.67; GA/MP1 = 2.00; LP2/LP1 = 1.51; MNL/MNW = 2.58. Thorax: L3 = 1.58 mm . Abdomen ( Fig. 18 ): LAS = 0.64 mm ; U = 0.34 mm ; U/HW = 0.43; U/LAS = 0.52. Chaetotaxy: Parietale with 10–12 temporal spines; position and number of secondary setae on legs are shown in Table 7 .