Navicordulia tumucurakensis, Fleck, Günther, 2017

Fleck, Günther, 2017, Notes on the genus Navicordulia Machado & Costa, 1995 (Odonata: Anisoptera: Corduliidae s. str.): description of a new species, phylogenetic affinities and aspects of biogeography, Zootaxa 4272 (2), pp. 251-262 : 252-256

Description of Navicordulia tumucurakensis sp. nov.

( Figures 1–9 )

Material. Holotype ♂, French Guiana, Maripasoula / Mitaraka, N 2°14' / W 54°27', 320m, SLAM, 15-III-2015, “ La Planète Revisitée , Guyane 2015” expedition, MNHN PNI, APA 973-1 . Deposited at MNHN, Paris.

Etymology. Declinable adjective: from the word “Tumucurake”, a name given by Amerindians to refer to the Tumuc-Humac/Mitaraka range (Gabriel 1898).

Description. A medium-sized dragonfly with long legs, long male caudal appendages, lacking a marked excavation of the male anal angle and superficially resembling a gracile Paracordulia ( Fig. 1 ). Head and thorax hairy. Body showing metallic reflections with brownish thorax and blackish abdomen, and lacking citron-yellow markings ( Figs. 1 , 4 , 8 ).

Head. Face, frons, vertex and occiput covered by strong black hair-like setae. Labium light brown yellowish, labrum light brownish orange, clypeus brown with some light lateral green metallic reflections, frons with lower margin brownish orange and with upper and dorsal parts with strong green metallic reflections. Vertex dark brown with green metallic reflections, slightly flattened on top, without any indentation or tubercle but with anterior upper margin slightly bilobed in posterodorsal view. Antennae dark brown with long flagellum. Eyes largely in contact dorsally ( Fig. 2 ) (see below). Posterolateral margin of eyes with a small marked indentation (remnant of larval eye, often encountered in corduliids). Occiput dark brown.

Thorax. Covered by pale hair-like setae. Legs long compared to body dimensions ( Fig. 1 ) (see below), hind leg being distinctly longer than half of HW (ca 57%) and distinctly longer than half of abdomen excluding caudal appendages (ca 64%). Legs with tibiae and tarsi blackish to dark brown, profemora light brown with apical fourth turning gradually dark brown, mesofemora mainly blackish/dark brown with about basal 2/3 of extensor/posterior side brown, metafemora blackish/dark brown. Tibial keels present on prothoracic and metathoracic legs and occupying respectively 27–31% and 90–94% of tibiae. Ventral tooth of tarsal claws well developed and situated at about 3/5 of claw. Prothorax light brown to yellowish, with posterodorsal rounded margin covered by a fringe of minute setae; no tergal process sensu Pinto & Lamas (2011) visible. Synthorax brown with strong green metallic reflections on mesepisternum, mesepimeron and metepimeron, (green metallic reflexions less marked on metepisternum and infraepisterna).

Wings ( Figs. 1 , 3 ): hyaline with a diffuse and very light saffron tinge on HW basal half; veins black to dark brown; membranulae well developed, greyish-brown and pterostigmata dark brown, trapezoidal with distal margin more oblique; FW nodus well shifted distally with base-nodus ratio 0.57 (see Machado & Costa, 1995); FW antenodal crossveins 9 of the first rank (between C and ScP) and 9 of the second rank (between ScP and R); FW antenodals of the first rank aligned or sub-aligned with those of the second rank but only Ax1 and Ax2 distinctly reinforced and bracketlike; HW antenodals 6 (first rank) + 6 (second rank) with those of first rank and those of second well aligned, reinforced and bracketlike, the reinforcement diminishing distally; FW postnodal crossveins 6; HW postnodal crossveins 8–9; cross veins distal to pterostigma 3; base of pseudo-IR1distinctly distal to Pt in FW and below Pt in HW; arculus at the level of Ax 2 in FW and slightly proximal to Ax 2 in HW; sectors of arculus meeting at base in FW and very shortly united in HW; bridges with only one crossvein placed distal to subnodal transverse; all hypertriangles and discoidal triangles free; FW subtriangles elongated and 2-celled; no HW subtriangles (submedian space crossed only by basal CuP between anal triangle and anal loop); position of anteroproximal angle of HW discoidal triangle shortly but distinctly proximal to posterior crossvein of arculus; Rspl well defined and covering one row of 6–7 cells on FW and one row of 5–6 cells on HW; Mspl well defined in FW and covering one row of 5 cells; Mspl less distinct in HW and covering one row of 4 cells; FW discoidal field with two rows of cells throughout and with MA and MP grossly parallel up to the nodus, distally slightly convergent; anal loop with 15–16 cells and distinct midrib; anal loop with 2 cells at submedian space margin and distally dilated with distinct toe/sole (posterior evagination) even if not strongly marked with sole (CuAb) made by 3 cells; anal loop and posterior wing margin separated by 2 rows of cells; anal triangle well defined, rather well elongated and 2-celled; typical generic anal excavation (posterior to distal end of anal triangle) poorly marked but with margin dorso-ventrally thickened and white coloured ( Fig. 4 ); anal angle poorly indicated.

Abdomen slender, longer than HW, brown on S1–2 and anterior part of S3, progressively turning black on S3, black on S4–5, black on dorsal and lateral S6-10, and blackish to dark rufous brown on ventral S6–10 ( Figs 1 , 4 ). Longitudinal ventral membranes and adjacent carinae on distal segments brown to yellowish ( Fig. 8 ). Light gloss of metallic green and cupreous on dorsal S3, light cupreous gloss on distal dorsal S4–5, and inconspicuous, hardly visible, metallic green or cupreous gloss on S6–9. In lateral view abdomen moderately swollen at S2 and anterior part of S3, narrowing from S3 to anterior half of S5, then slightly expanding again from distal half of S6 to S9 ( Fig. 1 ); in dorsal view constricting on S3, expanding progressively from distal S4 to posterior margin of S7, then slightly constricting again from proximal S8 to distal S9. Lateral carina extending from distal 2/3 of S4 to S8 and progressively better marked from S4 to S8. Dorsal carina weak. S1–4 and S10 oval or subcylindrical in cross section, and S5–9 hemicylindrical in cross section due to flattened ventral side; anterior lamina and hamule of the secondary accessory genitalia similar to those found in other species. S2 genital lobe rounded at apex, with a fringe of very long setae on ventral rounded border, at its posterior base a distinct protuberance bearing some straight setae ( Figs. 4–6 ).

Vesica spermalis of type ‘A’ sensu Machado & Costa (1995), similar to those figured by Machado & Costa (1995) and Pinto & Lamas (2010), with flagella well displaced on the right side and with sclerotized part of V4 ending as a distinct short distal horn (see Pfau 2011) occupying a slightly left displaced submedian position. Pilose complex of S7 structured as follows ( Figs. 7–8 ): sternite with anterior longitudinal carina rather short and weak extending from about proximal 4/10 of the sternite to about proximal 6/10; at distal end of the carina and not connected to this two lateral prominent knobs, oreillet-like with long, straight and caudally directed setae implanted on posterodorsal surface; between prominent knobs presence of anterior part of a longitudinal median elevated fold ending posteriorly as a small rounded knob bristling with straight and caudally directed setae, this knob flanked laterally, at base by short rims delimiting distal glabrous area; pleural membrane, between prominent lateral knobs and median small knob, with a brush of long straight caudally directed setae, this brush completed more laterally by some long setae well aligned on tergal ventral carina. Pilose complex of S8 comparable to those of other species (see Machado & Costa 1995) with an anterior glabrous area occupying the proximal 2/10 of the sternite continued by a field of long, fine, straight, and ventrally directed setae extending from proximal 2/10 of sternite to its posterior margin; longest setae of this field situated close to lateral margins of proximal 2/10 to 3/10 of sternite ( Fig. 8 ).

Cerci black to dark brown, rather thin and long, much longer than S9+10 (ratio length cerci / length S9+10 = 1.5) and about as long as S8+9 ( Figs. 8–9 ). Cerci in lateral view: with a short anterior well-excavated and carinate part extending from base to about proximal 3/10 of length and with a long posterior part deprived of carina and presenting a convex dorsal margin and a straight ventral margin showing thick pilosity (setae distinctly denser and longer on ventral portion than dorsal portion) ( Figs. 8 , 9 a); with ventral tubercle particularly poorly developed (= ventrolateral tubercle sensu Machado & Costa 1995, but here occupying a ventral position), simply indicated by a kind of smooth and very weak protuberance well chitinized, and well aligned with distal non-carinate part (only a minute concave discontinuity is visible) ( Fig. 9 a); with ventromedial carina and ventromedial tubercle sensu Machado & Costa (1995) absent or nearly so [at well-oriented grazing light, a ventral short (less than 1/20 of cerci length) smooth and very weak longitudinal fold (ventromedial carina?) is faintly visible, bent distally at right angle (ventromedial tubercle?) towards the ventral tubercle]. Cerci in dorsal view well separated at base by about 1.8 cercus width, then convergent from base to about proximal 4/10 of length with a marked constriction at 4/10, at constriction distally divergent to about 7/10 of length, and almost parallel from 7/10 to rounded apex (internal margin slightly divergent near apex) ( Fig. 9 b). Epiproct about 1/2 length of cerci, blackish to dark brown, thin and triangular in ventral or dorsal view and with apical margin shortly truncated and slightly bilobed due to tip curved upwards and forming a short acute ridge ( Fig. 9 ).

Measurements (mm). Total length (including caudal appendages) 42.5, line of eye contact ca 0.9, HW length 29.7, FW pterostigma 1.85 (C vein) to 1.5 (RA vein), HW pterostigma 1.75 (C vein) to 1.5 (RA vein), hind leg length (including coxa and trochanter) 16.8, hind leg tibia length 5.9, abdomen length (including caudal appendages) 31.0, cerci 3.9, inferior caudal appendage (epiproct) 2.0, abdomen width at S2 2.4, at anterior part of S4 (minimal width) 1.2, at posterior margin of S7/anterior margin of S8 (maximal width) 2.85.

Figures

FIGURE 1. Navicordulia tumucurakensis sp. nov., holotype. General habitus (specimen in ethanol).

FIGURES 2 – 3. Navicordulia tumucurakensis sp. nov., holotype: (2) top of the head showing the eyes seam, occiput on the right, scale bar 2 mm; (3) right wings, ventral view.

FIGURE 4. Navicordulia tumucurakensis sp. nov., holotype: metathorax, base of the hindwing and first abdominal segments, left lateral view (specimen in ethanol).

FIGURES 5 – 7. Navicordulia tumucurakensis sp. nov., holotype: (5) ventral portion of the abdominal segments 2 and 3 showing the secondary genitalia in right lateral view; (6) detail of the abdominal segment 2 genital lobe in right lateral view; (7) pilose complex of the abdominal segment: a) right latero-ventral view, b) ventral view.

FIGURE 8. Navicordulia tumucurakensis sp. nov., holotype. Terminal abdominal segments showing pilose complex and caudal appendages in left lateral view.

FIGURE 9. Navicordulia tumucurakensis sp. nov., holotype. Caudal appendages: a) left lateral view (with two last abdominal segments figured); b) dorsal view (with last abdominal segment); c) ventral view (cerci not figured).