Tramea binotata Nymph

Tennessen, Kenneth J., Trapero-Quintana, Adrian & Ferreira, Francisco De Assis Cruz, 2017, Description of the Nymph of Tramea binotata (Rambur, 1842) (Odonata: Libellulidae), Zootaxa 4337 (3), pp. 445-450 : 446-447

Tramea binotata Nymph Description

( Figs 1–10 )

Robust, elongate, mostly translucent green in life with isolated brown markings dorsally, integument covered with small spiniform setae and isolated hair-like setae; exuvia pale brown with color pattern less evident.

HEAD. Oval, L:W ratio about 2:3. Compound eyes occupy about 8/10 head lengthwise. Antenna very slender, 4.5–5.0 mm L, about equal to head L, long pale setae on apical antennomeres ( Fig. 1 ). Frons and most of occiput without setae or setal bases; rear of head with about 18–20 stout, elongate setae and fewer fine, hair-like setae. Prementum distal W 6.2 –6.9 mm, subequal to maximum head W; 5–7 larger lateral setae + 3 or 4 smaller medial setae = total number of 8–11, usually 9 or 10 ( Fig. 2 ); numerous very pale, fine setae on ental surface; ligula protruding anteriorly, finely crenulate, with sharp setae of irregular length; venter with 2 pairs of small, sub-lateral black spots (not visible on exuviae). Labial palp large, usually 7 or 8 palpal setae ( Fig. 3 ), rarely 6 or 9 on one side (95% with 7 or 8), small setella 0.24 mm long near base + 7 or 8 much smaller setae distal to setella (about ½ its L); distal margin about 3.9–4.1 mm long, 12–13 low marginal crenations, progressively lower and wider toward ventral corner, each bearing 4 or 5 stout, sharp setae up to 0.55 mm long ( Fig. 4 ); outer surface of palpal lobe with dark spots and blotches of variable size. Mandibular formula L 1234 y abc R 1234 y abcd; lateral surface with large brown oval spot and numerous basal pale setae ( Figs 5, 6 ).

THORAX. Prothorax trapezoidal, mostly translucent green in life (brown in exuviae), anterior lobe slightly darkened and devoid of setae, middle lobe darkened medially with a few spiniform setae on posterior margin, hind lobe large, with spiniform setae on posterior margin more numerous than on middle lobe. Pterothorax green in life except light brown medially and above legs; cluster of small spiniform setae dorsally on mesepisternum, another cluster laterally on mesepimeron above coxa, similar setae laterally also on metepimeron. Apex of hind wing sheath extending to posterior margin of S7. Legs very long and slender; pro- and mesothoracic femora with slight brown mark at ¾ L and at apex; metathoracic leg total L ≥ 20 mm (base of femur to apex of tarsus), femur with a narrow brown band at ¾ L and at apex, a few long, fine, hair-like setae and shorter stout setae, apex of femur extending beyond hind wing sheath, to mid-length of S7; tibiae with dense row of very long, hair-like setae.

ABDOMEN. Elongate, robust, convex dorsally, flat ventrally. Dorsal color pattern typical of genus, S1–7 pale beneath wing sheaths, laterally with mixed brown and pale markings, S8–10 brown medially, laterally with two pale, irregular blotches, the more lateral pale mark situated basally, S7–9 with a pair of small, black, sub-lateral spots ( Fig. 7 ); venter mostly pale, S2–6 with pair of isolated, brownish-red, sub-lateral spots (not visible on exuviae), S7 & S8 venter with pair of much smaller dark spots, S3–9 venter with lateral brown markings increasing in extent on more posterior segments, about ½ segment width on each side of S8 & S9 (retained on exuviae). No mid-dorsal hooks or protuberances; tergites S3–5 with numerous small spiniform setae laterally, S6–8 with closelyspaced small spiniform setae on most of dorsum including median ( Fig. 8 ), S8 mid-dorsum with density of about 30–45 spiniform setae per sq. mm, less dense on S9; dorso-posterior margins of S6–9 lined with closely-based, small sharp setae, S7 & S8 also with 5 or 6 widely-spaced, very long hair-like setae; dorsum of S10 devoid of setae except posterior margin lined with small sharp setae; lateral margins of S5–7 with a few spinules, increasing in size and number posteriorly; S8 & S9 with very long postero-lateral spines typical of genus, curved inward slightly, their medial and lateral margins bearing large spinules and spurs, those on S9 outstanding, up to 0.35 mm long ( Fig. 9 ); S8 postero-lateral spine L 2.05–2.45 mm, S9 postero-lateral spine L 2.40–3.20 mm, 1.7–2.1 and 2.5–3.4 times mid-dorsal L of respective segment; ratio S8 spine L:S9 spine L = 0.76–0.88. Anal appendages acute, sharp, cercus L 0.76–0.84 epiproct L, epiproct tip short of paraprocts tips by 0.85–0.88 mm ( Fig. 10 ); epiproct triangular, wide at base, apical ½ acuminate with 4 or 5 medial stout spurs, very long hair-like setae laterally ( Fig. 10 ); cercus slender, acute, tips sharp; paraproct sharply acuminate, longer than epiproct, lateral margin with 4 or 5 long stout spinules and numerous long, fine, pale and dark setae, inner margin with similar setal arrangement but stout setae not as prominent.

Measurements (mm): TL 22.0–26.5; head W 6.75 –7.50; metathoracic femur L 7.0–8.3, epiproct L 2.25–2.50, cercus L 1.80–2.15.

Specimens examined (total 19): Brazil, Amazonas, Tabatinga municipality (-4.2031°, -69.9430°, elev. 95 m, near the borders of Colombia and Peru ), 7-8 Apr. 2016, 7 exuviae (associated), A. Trapero and F. Cruz leg ; Ecuador, Orellana Province, pond S of Loreto (-0.81992°, -77.31305°), 2 Nov. 2013, 2 exuviae (associated), 1 F-0 nymph, K. J. Tennessen leg. ; Esmeraldas Province, pond 5.6 km NW of Lita, near Finca Consuegros (0.891°, - 78.512°), 3 Feb. 1997, 1 F-0 nymph, K. J. Tennessen leg. ; Venezuela, Portuguesa state, small reservoir near Rio Las Marias, E of Guanare (approx. 9.04°, -69.69°), 12 Feb. 2004, 8 nymphs, P. B. McIntyre leg . Brazil specimens deposited in Laboratorio de Biologia, Universidade do Estado do Amazonas, Tabatinga, Amazonas , Brasil. Ecuador and Venezuela specimens deposited in Florida State Collection of Arthropods , Gainesville, Florida .

Figures

FIGURES 1 – 6. Tramea binotata: 1) left antenna; 2) prementum, ental view; 3) right palpal lobe, ental view (stout setae on distal crenations omitted); 4) middle crenations # 6 – 8 on distal margin of palpal lobe, enlarged (scale bar = 0.5 mm); 5) left mandible; 6) right mandible. Not to scale.

FIGURES 7 & 8. Tramea binotata: 7) abdomen, dorsal view; 8) minute spiniform setae on middle portion of segment 7.

FIGURES 9 & 10. Tramea binotata: 9) abdominal segments 8 & 9 postero-lateral spines, ventral view; 10) anal appendages, dorsal view (stout spurs and long setae on paraprocts omitted for clarity).