Oreiallagma thelkterion ( De Marmels 1997 ) De Marmels, 1997

Ellenrieder, Natalia Von & Garrison, Rosser W., 2008, Oreiallagma gen. nov. with a redefinition of Cyanallagma Kennedy 1920 and Mesamphiagrion Kennedy 1920, and the description of M. dunklei sp. nov. and M. ecuatoriale sp. nov. from Ecuador (Odonata: Coenagrionidae), Zootaxa 1805, pp. 1-51 : 48-49

Oreiallagma thelkterion ( De Marmels 1997) comb. nov.

Figures 5 ; 8a; 29; 49; 86; 91; 104

Cyanallagma thelkterion De Marmels 1997: 138 –139, 152–156, figs. 7, 13, 19, 31, 38, 43, 49, 63, 64, 70, 82; in key for northern Cyanallagma species, description of male and female, illustrations of male S10, genital ligula, posterior lobe of prothorax of male and female, pterothorax, FW pt, male S6–10 and female S8–10, map). Tsuda 2000: 31 (synonymic list).

Types: ɗ holotype in MIZA (not examined); 4 ɗ paratypes, 1 Ψ paratype (MIZA); 1 ɗ paratype (RWG) (examined).

Specimens examined.: VENEZUELA. Mérida State: Monte Zerpa, Santa Rosa Experimental Station, 29.iii.1992, C. Chaboo leg., 1 ɗ paratype (RWG).

Characterization. Medial lobe of male posterior lobe of prothorax heart-shaped, markedly constricted at base, with a moderate medial concavity on posterior margin, and with each lateral lobe bilobate ( Fig. 29 a; as in O. prothoracicum ); of female not constricted at base and with moderate medial concavity on posterior margin ( Fig. 29 b). Distal segment of genital ligula ( Fig. 49 ) wider at apex than at base (unique), with a pair of latero-apical lobes recurved and directed basally, a small sclerotized latero-medial lobe, and two ental membranous transverse folds, one connecting latero-medial lobes and the second basal to them (as in O. acutum and O. quadricolor ), the latter medially projected into an inner process (unique; Fig. 49 c). Dorsal process of male cercus shorter than ventral process, digitiform, and pointed ( Figs. 86 ; 91; unique). Male dorsum of S1–3 reddish orange to dark brown; of S4 reddish orange to black; of S5–7 and S10 black; of S8–9 blue ( Fig. 5 ). Female dorsum of S2–3 orange; of S4–7 and S10 successively darker brown; of S8 black with posterior blue spot; of S9 blue with anterior black spot.

Diagnosis. This species, unique by cercus morphology, is diagnosed under O. acutum .

Biology. Adults collected in the neighborhood of ponds rich in riparian vegetation in Trujillo State ( De Marmels 1997) and within cloud forest away from water in Táchira state (De Marmels pers. comm.); larva unknown, although we suspect that like O. quadricolor it will be found to breed in phytotelmata.

Distribution. Venezuela (Trujillo, Mérida, and Táchira States), from 1650 to 2050 m above sea level ( Fig. 104 ).

Figures

FIGURE 5. Color pattern of head, dorsal view, and body, lateral view, Oreiallagma thelkterion, male paratype, Venezuela, Monte Zerpa.

FIGURE 104. Distribution of species of Oreiallagma in South America.

FIGURES 25 – 29. Posterior lobe of prothorax. (25) Oreiallagma prothoracicum, male paratype, Ecuador, Intaj, (a) dorsal view, (b) medio-dorsal view; (26), O. oreas, male holotype, Colombia, Monte Socorro, dorsal view; (27) O. acutum, male lectotype, Bolivia, Río Zongo, dorsal view; (28) O. quadricolor, Peru, (a – b) posterior lobe of prothorax, male, holotype, Santa Ana, (a) dorsal view, (b) antero-lateral view, (c) female, Morro Leguía, dorsal view; (29) O. thelkterion, Venezuela, dorsal view, (a) male, Monte Zerpa, (b) female, Guaramacal.

FIGURES 49 – 53. Distal segment of male genital ligula, (a) lateral view, (b) ectal view, (c) ental view. (49) Oreiallagma thelkterion, paratype, Venezuela, Monte Zerpa; (50) O. quadricolor, holotype, Peru, Santa Ana; (51) O. acutum, lectotype, Bolivia, Río Zongo; (52) O. oreas, holotype, Colombia, Monte Socorro; (53) O. prothoracicum, paratype, Ecuador, Intaj. i. p.: inner process; l-ap. l.: latero-apical lobe; l-m. l.: latero-medial lobe; te. f.: terminal fold; tr. f.: transverse fold; scl. l-ap. f.: sclerotized latero-apical fold.

FIGURES 85 – 89. Male caudal appendages, medio-dorsal view, (86 b) medial view of cercus, (88 b) medio-ventral view, (88 c) dorsal view. (85) Oreiallagma acutum, lectotype, Bolivia, Río Zongo; (86) O. thelkterion, paratype, Venezuela, Monte Zerpa; (87) O. prothoracicum, holotype, Ecuador, Intaj; (88) O. quadricolor, holotype, Peru, Santa Ana; (89) O. oreas, holotype, Colombia, Monte Socorro. d. p.: dorsal process; v. ap. p.: ventro-apical process; v-b. p.: ventro-basal process; scal. cu.: scalariform-like cuticle.