Progomphus, Selys, 1854

Molineri, Carlos, Rodríguez, José Sebastián, Leiva, Marta & Márquez, Javier Andrés, 2023, Diagnoses and key for the larvae of Progomphus Selys, 1854 from Argentina (Anisoptera: Gomphidae), with first larval descriptions for P. aberrans Belle, 1973 and P. kimminsi Belle, 1973, Zootaxa 5297 (2), pp. 239-259 : 258

Key to the larvae of Progomphus from Argentina (four species remain unknown in this stage: P. auropictus , P. australis , P. basistictus and P. costalis ).

1 Last antennomere (the fourth) short, spherical ( Figs. 6a, 11b, 13b), pro- and mesotibiae with distal spur ( Figs. 6a, 13a), abdomen with posterolateral spines on S6–9........................................................................ 2

- Last antennomere long (at least longer than antennomere1-2 combined) and slender, cylindrical ( Figs. 2b, 4b, 9b), pro- and mesotibiae without distal spur ( Figs. 2c, 4c), abdomen with posterolateral spines at least on S5–9 ( Figs. 1i, 4d, 9a)........ 4

2 Sternum of S8 formed by 3 plates ( Fig. 6c)....................................................... P. joergenseni

- Sternum of S8 formed by 5 plates ( Figs. 11d, 13h)........................................................... 3

3 Third antennomere flat and wide, subcircular in shape ( Fig. 11b), ligula with 14 marginal tubercles ( Fig. 10f)..... P. lepidus

- Third antennomer subcylindrical, elongated ( Fig. 13b), ligula with only 2 median marginal tubercles ( Fig. 12e).................................................................................................. P. phyllochromus

4 Anal pyramid short (epiproct subequal in length to S10, Figs. 4d–e), posterolateral spine absent on S4 ( Fig. 4d)................................................................................................... P. complicatus

- Anal pyramid long and slender (epiproct as long as or longer than S9 and 10 combined, Figs. 2d, 2g –i, 9d–g), posterolateral spine present on S4 ( Figs. 1i, 8c)......................................................................... 5

5 Small abdominal dorsal tubercles present on S1–9, sometimes very reduced on S5 to 8 ( Figs. 1h, 2d–e), posterolateral spines on S2–9 ( Figs. 1i, 2d).......................................................................... P. aberrans

- Small abdominal dorsal tubercles present on S1–3 ( Figs. 8a–b, 9c), posterolateral spines on S4–9 ( Figs. 8c, 9a)... P. kimminsi