Platynectes reticulosus, (Clark, 1863)

Alarie, Yves, Michat, Mariano C., Short, Andrew E. Z. & Watts, Chris H. S., 2024, Larval ground plan of Platynectes Régimbart, 1879 reconsidered: description of the larvae of three species with phylogenetic considerations (Coleoptera: Adephaga, Dytiscidae), Zootaxa 5458 (3), pp. 301-331 : 317

P. reticulosus ( Clark, 1863)

Source of material. The larvae studied were collected in association with adults at the following locality: South Australia: 1 Km S. Nangwarry, 9.x.1997, leg. C.H.S. Watts.

Diagnosis. With the exception of P. agallithoplotes whose larva remains easily recognizable for the reasons mentioned above, the larva of P. reticulosus is more likely to be confused with those of either P. curtulus , P. davidorum , P. decemnotatus , or P. reticulosus of which it can easily be identified by the combination of following characters: frontoclypeus at level of adnasalia ( Figs 44 , 58 ), presence of four lamellae clypeales (instar I) ( Fig. 44 ), presence of an occipital suture (instars II–III) ( Fig. 58 ), A/MP <1.50, A3’ not protruding, hole-like ( Fig. 47 ), galea (instar III) <0.40 times length of maxillary palpomere 1, prementum with one additional seta dorsally ( Fig. 51 ), primary setae LA3, LA4, LA5, LA8 minute ( Fig. 51 ), primary seta LA10 inserted at about same level as seta LA11 ( Fig. 51 ), primary seta TA1 inserted distally ( Fig. 54 ), primary setae CO7 and CO10 elongate, much longer than either seta CO4 or CO5 ( Fig. 53 ), absence of secondary dorsal spine-like setae on femur (instar III) ( Figs 60–61 ), metatibia with spinulae along ventral margin ( Figs 60–61 ), metathoracic legs (instar III) 2.50–3.40 times as long as HW, primary setae AB8 and AB14 spiniform ( Fig. 55 ), and urogomphus lacking secondary setae ( Fig. 59 ).

Figures

FIGURES 44–52. Platynectes reticulosus (Clark, 1863), instar I: 44. head capsule, dorsal aspect; 45. head capsule, ventral aspect; 46. antenna, dorsal aspect; 47. antenna, ventral aspect; 48. mandible, dorsal aspect; 49. maxilla, dorsal aspect; 50. maxilla, ventral aspect; 51. labium, dorsal aspect; 52. Labium, ventral aspect. AN, antenna, FR, frontoclypeus; gAN, antennal group; gLA, labial group; gMX, maxillary group; LA, labium; LC, lamellae clypeales; MN, mandible; MX, maxilla; PA, parietal; TP, tentorial pits; sp, spinula. Numbers and lowercase letters refer to primary setae and pores, respectively; * refer to either additional seta or pore. Scale bars = 0.1 mm.

FIGURES 58–61. Platynectes reticulosus (Clark, 1863), instar III: 58. head, dorsal aspect (surface spinulae not represented); 59. last abdominal segment and proximal part of urogomphi, dorsal aspect; 60. prothoracic leg, anterior surface; 61. prothoracic leg, posterior surface. Scale bars = 0.5 mm (Fig. 58); 0.2 mm (Figs 59–61).

FIGURES 53–57. Platynectes reticulosus (Clark, 1863), instar I: 53. metathoracic leg, anterior surface; 54. metathoracic leg, posterior surface. 55. abdominal segment VIII, dorsal aspect; 56. abdominal segment VIII, ventral aspect; 57. urogomphus, dorsal aspect. AB, abdominal segment VIII; CO, coxa; FE, femur; TA, tarsus; TI, tibia; TR, trochanter; UR, urogomphus. Numbers and lowercase letters refer to primary setae and pores, respectively; * refer to additional setae. Scale bars = 0.1 mm.