Description of the final instar larva of Homeoura lindneri (Ris, 1928) and redescription of the larva of H. chelifera (Selys, 1876) (Odonata: Coenagrionidae) Author Lozano, Federico Author Muzón, Javier Author Torres, Sabrina text Zootaxa 2009 2231 47 54 journal article 10.5281/zenodo.190289 78effc7c-8853-493f-985a-1d3d96469b77 1175-5326 190289 Homeoura lindneri ( Ris, 1928 ) Acanthagrion lindneri Ris, 1928 : 41 –44, figs. 1–2 (description of male and female). Homeoura lindneri : von Ellenrieder, 2008 : 96 –97 (complete synonymy). Description of final instar larva (figs. 1–2). Head . Almost 2.15 times as wide as long at its widest point. Posterolateral margins rounded, with more than 20 spinules. Antennae seven-segmented; third antennomere the longest. Mandibular formula (figs. 1c–d): L 1+2 3 4 5 y a b (1<3<2<4<5) / R 1+2 3 4 5 y a (1<3<2<4<5) . Labium: articulation of pre- and postmentum between bases of coxae I; prementum (fig. 1a) sub-triangular, ratio of maximum length to maximum width 1.27; anterior margin convex and slightly crenulated; with 7–8 premental setae (3+3, 4+3 or 5+3), the inner ones smaller than 0.5 the length of the external ones; lateral margin with 3–5 spines; latero-distal margin with 2 or 4 spines. Labial palp (fig. 1b): outer margin with 3–4 setae; distal margin with 8–9 teeth (decreasing in size laterally); movable hook longer than half the length of outer margin. Thorax . Wing pads reaching mid length SIV; femora without spines on flexor margin; femora I-II with short spines along the entire extensor margin; femur III with short spines restricted to distal third of extensor margin. Tibiae with short spines restricted to distal third of flexor margin (increasing in number towards tibia III); without spines along extensor margin. Abdomen . Cylindrical. SI–VIII with spinules along lateral carina; posterior margins of SV–X with a row of spines. Cerci sub-conical, smaller than 0.5 the length of SX. Female gonapophyses (fig. 2c–d) reaching distal end of SX, outer ones with a ventral row of denticles. Lateral caudal lamellae (fig. 2a) lanceolate (almost 0.8 the length of the abdomen); ratio of maximum length to maximum width 8.31; nodus at approximately 0.58 the length of the lamella; with transverse suture (visible on ventral half of the lamella), 14–18 dorsal spines, and 27–36 ventral spines; prenodal area with a rounded dark spot near base of lamella, and scattered groups of dark branching tracheoles, most strongly colored at margins; postnodal area with three transverse black stripes (the proximal do not reach the dorsal margin). Medial caudal lamella (fig. 2b) lanceolate (almost 0.72 the length of the abdomen); ratio of maximum length to maximum width 8.27; nodus at approximately 0.56 the length of the lamella; with transverse suture, 24–26 dorsal spines and 14–16 ventral spines; color pattern similar to that of lateral caudal lamellae. Measurements (in mm; average, range in square brackets; females N=3, unless indicated otherwise). Total length (without caudal lamella): 12.23 [12.10–12.50]. Head: maximum length (N=2): 1.30; maximum width (N=2): 2.80. Prementum: maximum length: 1.87 [1.80–1.90]; maximum width: 1.47 [1.40–1.60]; outer premental seta (N=1): 0.35. Thorax: femur I: 1.67 [1.60–1.70]; femur II: 2.33 [2.30–2.40]; femur III: 2.93 [2.80–3.00]; tibia I: 2.00 [1.80–2.20]; tibia II: 2.50 [2.40–2.60]; tibia III: 3.10 [3.00–3.20]; inner wing pads maximum length: 3.73 [3.60–3.80]; outer wing pads maximum length: 3.60 [3.40–3.70]. Abdomen: total length: 7.53 [7.20–8.00]; SIX length: 0.70; SX length: 0.50; cerci length: 0.10; female gonapophyses length: 1.03 [1.00–1.10]. Lateral caudal lamella: maximum length: 6.07 [6.00–6.20]; maximum width: 0.73 [0.70– 0.80]; dorsal row of spines length: 3.03 [2.80–3.20]; ventral row of spines length: 3.57 [3.30–3.70]. Medial caudal lamella: maximum length: 6.20; maximum width (N=2): 0.75 [0.70–0.80]; dorsal row of spines length: 3.07 [2.50–3.40]; ventral row of spines length: 2.63 [1.90–3.10]. Specimens examined. Homeoura lindneri : Argentina , Entre Ríos Province, Diamante Department, Pre- Delta National Park, 32° 07’ 57’’S , 60° 40’ 32’’W ; 23–24/XI/2006 , coll. A. Garré, J. Lambruschini, F. Lozano, L. Ramos & S. Weigel Muñoz, 3 female exuviae (reared) [emerged: 28/XI/2006 , 30/XI/2006 , 06/XII/ 2006 ].