Platynectes agallithoplotes, Gustafson, Short & Miller, 2016

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 : 303

P. agallithoplotes Gustafson, Short & Miller, 2016

Source of material. The larvae studied were collected in association with adults at the following localities: Venezuela: Bolivar State: Los Pijiguaos; morichal / rock outcrop, 80 m; 06°35.617’N 66°42.238’W, 16.ix.2007, one instar II and two instar III, leg. A.E.Z. Short, M. Garcia, L. Joly; Río Aponwao , small streamlet, 1340 m; 05°.50’.49.2N’’, 61°28’.2.4’’W, 31.vii.2008, one instar II and one instar III, leg. A.E.Z. Short, M. Garcia; 2 km East Río Chucivero , rock outcrop seeps, 45 m; 07°.29’.47.3’’N, 65°51’.44.8’’W, 06.viii.2008, two instar III, leg. A.E.Z. Short, M. Garcia, L. Joly; Los Pijiguaos , stream at outcrop, 80 m; 06°.35.617’N, 66°49.238’W, 08.vii.2010, one instar I and two instar III, leg. A.E.Z. Short, Teles, Arias; Rock outcrop by morichal, 75 m; 06°.52.196’N, 66°35.405’W, 09.vii.2010, three instar III, leg. A.E.Z. Short, Teles, Arias. Larval specimens were collected in seepages on granite outcrops of Guiana Shield (see figures 20–21 in Gustafson et al. (2016)). In most cases, these seepages are seasonal and go completely dry for part of the year.

Diagnosis. Larvae of P. agallithoplotes are unique within all known Agabinae by the presence of numerous additional setae on the cephalic capsule ( Figs 1–2 ), abdominal segment VIII ( Figs 12–13 ) and urogomphi ( Fig. 14 ). Among other unique characters that facilitate a readily recognition of this species within other known Platynectes described in detail (i.e., P. bakewelli , P. curtulus , P. davidorum , P. decemnotatus , and P. reticulosus ) are: the presence of six lamellae clypeales (instar I) ( Fig. 1 ), prementum subquadrate, as long as broad, not fully sclerotized ventrally ( Figs 8–9 ), primary seta TA1 inserted medially ( Fig. 11 ) primary setae AB8 and AB14 lanceolate ( Fig. 12 ), presence of several hair-like setae notably on metacoxa, metatibia and metatarsus (instar II–III) ( Figs 24–25 ).

Figures

FIGURES 1–9. Platynectes agallithoplotes Gustafson, Short & Miller, 2016, instar I: 1. head capsule, dorsal aspect; 2. head capsule, ventral aspect; 3. antenna, dorsal aspect; 4. antenna, ventral aspect; 5. mandible, dorsal aspect; 6. maxilla, dorsal aspect; 7. maxilla, ventral aspect; 8. labium, dorsal aspect; 9. 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 additional setae (not labelled in Figs 1–2 owing to large number). Scale bars = 0.1 mm.

FIGURES 10–14. Platynectes agallithoplotes Gustafson, Short & Miller, 2016, instar I: 10. metathoracic leg, anterior surface; 11. metathoracic leg, posterior surface. 12. abdominal segment VIII, dorsal aspect; 13. abdominal segment VIII, ventral aspect; 14 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 (not labelled in Figs 12–14 owing to large number). Scale bars = 0.1 mm.

FIGURES 22–25. Platynectes agallithoplotes Gustafson, Short & Miller, 2016, instar III: 22. prothoracic leg, anterior surface; 23. prothoracic leg, posterior surface; 24. metathoracic leg, anterior surface; 25. metathoracic leg, posterior surface. Scale bar = 0.2 mm.