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 Molineri, Carlos Rodríguez, José Sebastián Leiva, Marta Márquez, Javier Andrés Zootaxa 2023 2023-06-01 5297 2 239 259 4MR55 Ris, 1918 Ris 1918 [151,616,834,861] Insecta Gomphidae Progomphus Animalia Odonata 16 255 Arthropoda species phyllochromus  Other material.  ARGENTINA: 1 larva(IBN-O-117) from Tucumán, Trancas, El Boyero, arroyo Pozo del Pescado, 26.18948° S, 65.28417° W,  784 m,  17/Dec/2016, C. Molineri& J. Rodriguezleg.;  1 larva(IBN-O-119) from Tucumán, Monteros, Pueblo Viejo, arroyo Yacuchina, 27.14083° S, 65.76805° W,  945 m,  10/Feb/2000,  Molineri et al.leg.;  1 larva(IBN-O-116) from Jujuy, Ledesma, Caimancito, río Zora, 23.77222° S, 64.61250° W,  385 m,  16/Nov/2014, E. Dominguez& C. Molinerileg.;  3 larvae(IBN-O-118), same data except:  7/Aug/2014, J. Rodriguezleg. Larval diagnosis. The larval stage of  P. phyllochromuscan be distinguished from other described larvae in the genus by the following combination of characters: fourth antennomere reduced, knob-like ( Fig. 13b); mandibular formula: L 1234 0 a (m 1,2,3,4,5) b, R 1234 y a+b ( Figs. 12a–b); galeolacinia with 4 ventral teeth, the first (basal) one 1/2 length of the second ( Fig. 12c), palp thick ( Fig. 12d); prementum subrectangular ( Figs. 12f, h), ligula with a pair of contiguous submedian tubercles ( Fig. 12e), margin with two rows of flat setae, both formed by slender setae, those of the ventral row less than ½ length of the dorsal setae; lateral margins of prementum bare, dorsal surface with 3 submedian setae and a grumose submedian area ( Fig. 12h); labial palp with smooth margins, inner apical projection with sclerotized margin, tongue-like, reaching basal 1/2 of movable hook, movable hook stout slightly shorter than outer palpal margin ( Fig. 12g); tarsal claws not cheliform, normal (long and acutely pointed, flattened), hind claw with a subapical seta; thorax and legs with whitish setae; pro- and mesotibia with distal spurs; hind tarsi light colored; posterolateral spines on S6–9 ( Fig. 13e); blunt relatively large dorsal tubercles on terga S2–9 ( Fig. 13d); sternum S2–9 formed by three plates, except sternum S8 formed by 5 plates ( Figs. 13e, h); apical abdominal segments and anal pyramid stout, relative length of sternum S8: S9: S10 (1): epiproct = 1.3: 1.2: 1:1.1 (Figs. 14a, f, g).  Limongi (1983)described the larva of  P. phyllochromusbased on 20 exuviaof both sexes, it is not clear if the association with adult was direct or by supposition. Differences between this description and our material include the presence of small median tubercles on margin of ligula, and the group of dorsal setae on each side of the prementum, not mentioned in Limongi (1983). Mandibles and maxilla are described here for the first time and resulted useful to further diagnose the species. Among the Argentinean species, the larva of  P. phyllochromusis similar to  P. lepidusand  P. joergenseni, see discussion under this last species for further comparisons.   FIGURE 12.  P. phyllochromusRis, last instar larval exuvia: a, left mandible, occlusal view; b, right mandible, occlusal view; c, maxilla, ventral view (arrow indicates first tooth); d, same, dorsal view; e, ligula. detail of flat marginal setae; f, prementum, ventral view; g, detail of labial palp, ventral view; h, prementum with detail, dorsal view.   FIGURE 13.  P. phyllochromusRis, last instar male larva: a, dorsal habitus; b, head and pronotum, dorsal (antennomeres are numbered); c, detail of tibial spurs (ts), ventral; d, abdomen, lateral; e, same, ventral; f, anal pyramid, dorsal; g, same, lateral; h, abdominal sterna S8–10 (numbers indicate plates on S8). Distribution. Argentina( Jujuy, Salta, Santiago, Tucumán), Bolivia, Brazil, Perú, Venezuela, Colombiaand Ecuador( Belle 1973; Pérez-Gutiérrez et al.2011; Koroiva et al.2020; Lozano et al.2020). 4122321301 2016-12-17 C. Molineri & J. Rodriguez Argentina Reared 890 -25.47611 rio Las Conchas 1 -64.97666 Metan 16 255 3 1 2 Salta 4122321337 2017-12-30 C. Molineri & J. Rodriguez Argentina Burruyacu 930 -26.49981 Segunda 1 -64.99804 Villa Padre Monti 16 255 6 3 3 Tucuman 4122321326 2022-01-29 C. Molineri & G. Fontanarrosa Argentina Burruyacu 668 -26.61046 rio Tapia 1 -65.26338 Tapia 16 255 5 1 3 1 Tucuman 4122321306 2016-12-17 C. Molineri & J. Rodriguez Argentina Trancas 784 -26.18948 Pozo del Pescado 1 -65.28417 El Boyero 16 255 1 1 Tucuman 4122321339 2000-02-10 Argentina Monteros 945 -27.14083 Yacuchina 1 -65.76805 Pueblo Viejo 16 255 1 1 Tucuman 4122321336 [151,363,1267,1293] Argentina Molineri 16 255 1 4122321303 2014-11-16 E. Dominguez & C. Molineri Argentina Ledesma 385 -23.77222 rio Zora 1 -64.6125 Caimancito 16 255 1 1 Jujuy 4122321330 2014-08-07 J. Rodriguez Argentina Ledesma 385 -23.77222 rio Zora 1 -64.6125 Caimancito 16 255 3 3 Jujuy