Navicordulia pascali, Fleck & Juillerat, 2019

Fleck, Günther & Juillerat, Laurent, 2019, The genus Navicordulia Machado & Costa, 1995 (Insecta, Odonata, Corduliidae s. str.): new species, identification key for males and data on ecology and distribution, Zoosystema 41 (27), pp. 553-565 : 554-559

Navicordulia pascali n. sp.

( Figs 1-4 )

urn:lsid:zoobank.org:act:B097AFD1-A942-4829-9AEA-FDAE462979DD

MATERIAL EXAMINED. — Holotype. ♂, French Guiana, Cayenne Province, St-Elie, Barruol Mounts , 4°19’N, 53°17’W, 170 m, 7.III.2013, at light trap, P.-H. Dalens, S. Fernandez & S. Brûlé leg., MHNN. Paratype. ♂, French Guiana, Maripasoula / Mitaraka, 2°14’N, 54°27’W, 320 m, SLAM, 15.III.2015, “ La Planète Revisitée, Guyane 2015” expedition, MNHN PNI, APA 973-1, canopy interception trap label MI-15-0629-03, MNHN .

ETYMOLOGY. — This new species is dedicated to Mr Olivier Pascal, head and responsible of the expedition “Our Planet Reviewed Guyane-2015”, during which the paratype was collected. The first author is grateful for the kind invitation to participate in this expedition.

DESCRIPTION

Holotype

State of preservation. Very good. Only a few cells at apex of the left FW are missing, and S7-9 are artificially slightly laterally compressed.

Body. Medium-sized dragonfly. Head and thorax hairy. Body with metallic reflections, blackish abdomen and lacking citron-yellow markings ( Fig. 1A ).

Head. Face, frons, vertex and occiput covered by strong black hair-like setae ( Fig. 1B ). Labium light brown yellowish, labrum light brownish orange, clypeus brownish orange, frons with lower margin light brownish orange and with upper and dorsal parts with strong green to bluish metallic reflections (depending of light incidence, Fig. 2 ). Vertex dark brown with green metallic reflections, slightly flattened due to the presence of two very low tubercles. Antennae dark brown with long flagellum. Eyes in contact over a rather long distance dorsally of c. 0.9 mm ( Fig. 1B ). Posterolateral margin of eyes with a small indentation (often encountered in corduliids). Occiput dark brown.

Thorax. Covered by pale hair-like setae ( Fig. 1B ). Legs relatively long compared to body dimension, hind-leg being distinctly longer than the half of the HW (c. 59%) and distinctly longer than the half of the abdomen excluding anal appendages (c. 65%). Legs with tibiae dark brown to blackish, tarsomeres blackish and tarsal claws dark brown; profemora light brown with apical half turning gradually dark brown ( Fig. 1B ), mesofemora mainly blackish/dark brown with about basal 1/4 brown, metafemora blackish/dark brown. Mesotrochanter with a lateral row of eight blunt small spines, metatrochanter with reduced similar row with only three or four smaller spines. Tibial keels present on prothoracic and metathoracic legs and occupying respectively 25-26% and 83-85% of the 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 rather long hair-like setae; no tergal process sensu Pinto & Lamas (2010) visible. Synthorax brown with strong green metallic reflections and some copper reflections depending of light incidence ( Fig. 1A, B ).

Wings ( Fig. 2A, B ). Light saffron tinged; veins black to dark brown; membranulae well developed, brown; pterostigmata dark brown, with proximal and distal margins almost parallel, distal margin being slightly more oblique than proximal one (angular difference c. 20° in FW and 10° in HW); FW nodus moderately shifted distally with base-nodus ratio 0.54 (see Machado & Costa, 1995); FW antenodal crossveins 10 of the first rank (between C and ScP) and 9-10 of the second rank (between ScP and R); four basal and four distal FW antenodals of the first rank aligned or sub-aligned with those of the second rank but only Ax1 and Ax2 distinctly reinforced and bracket-like; gap separating Ax1 and Ax2 distinctly more important than gaps separating other antenodals; 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 6-8; HW postnodal crossveins 8; crossveins distal to pterostigma 2-3 (2 on left HW); base of pseudo-IR1 distinctly distal to Pt in FW and below Pt in HW; base of the sectors of arculus slightly proximal to Ax 2 in FW and HW; sectors of arculus very shortly united in FW and HW; bridges with only one crossvein, this one 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 antero-proximal angle of HW discoidal triangle shortly but distinctly proximal to posterior crossvein of arculus; Rspl rather well defined, with concavity distinct but vein somewhat zigzagged and covering one row of 5-6 cells on FW and HW; Mspl rather poorly defined in FW and covering one row of 4 cells; Mspl weak in HW and covering one row of about 4 cells; FW discoidal field with two rows of cells except at posterior wing margin (3 cells) and with MA and MP grossly parallel up to distal part of Mspl, distally very slightly convergent; anal loop with 11-13 cells and distinct midrib; anal loop with 2 cells at submedian space margin, distally not dilated, thus without distinct toe and with sole (CuAb) made by 2 cells; anal loop and posterior wing margin separated by 2 rows of cells throughout; anal triangle well defined, rather well elongated and 2-celled; typical generic strong anal triangle excavation; anal angle strongly marked.

Abdomen. Slender but distinctly club-shaped distally in dorsal view, slightly longer than HW, brown on S1-2 and anterior part of S3, progressively turning black on S3, black on S4- 10. Longitudinal ventral membranes and adjacent carinae on S7-9 brown to yellowish. Green and purple metallic light gloss on dorsal S2-5, hardly visible metallic purple gloss on dorsal S6-7 and faintly visible green metallic gloss on dorsal S8-9. In lateral view abdomen 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. 1A ); in dorsal view constricting on S3, expanding progressively from distal S4 to posterior margin of S7, then constricting again at S9. Lateral carina extending from distal 2/3 of S4 to S8, inconspicuous on S4 and progressively better marked from S4 to S8. Dorsal carina weak to absent, except on S10, where it appears as a small crest. 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 secondary accessory genitalia similar to those found in other species ( Fig. 2C ). S2 tergal ventral margin bearing anteriorly a dense fringe of long and strong setae and delimiting distally a triangular genital lobe caudad directed ( Fig. 2C ). Vesica spermalis ( Figs 2 D-G) on the whole similar to that of the other species; V4 median flagellum stronger, much strongly sclerotized and distinctly longer than lateral flagellum and therefore vesica spermalis close to the type B of Machado & Costa (1995); sclerotized part of V4 ending as a distinct and well erected distal horn (see Pfau 2011); no trace of a third small flagellum (see below). Pilose complex of S7 mostly hidden but visible parts identical to those of paratype (see below). 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 4⁄10 of sternite (cf. Fig. 4F ). Cerci (superior anal appendages) blackish/dark brown, rather short, about as long as S9+ 10, grossly club-shaped with in dorsal view a thinner anterior part extending from base to about distal 4⁄10 of cercus length and a posterior part larger and with rounded apex ( Fig. 3A ). Cerci in dorsal view well separated at base, slightly convergent from base to about proximal 6⁄10, and almost parallel from proximal 6⁄10 to apex ( Fig. 3A ). Cerci with a smooth and small dorsal tubercle close to inner margin and in contact with S10, with strong basal ventral tooth situated at distal 2⁄10, and with well-developed lateral tubercle sensu Machado & Costa (1995) situated at distal 7⁄10 ( Fig. 3 ); presence of a low ventral elongated bulging devoid of setae (ventro-medial tubercle?) extending from about 5⁄10 to near the level of lateral tubercle at distal 7⁄10 ( Fig. 3B ). Cerci with two strong lateral carinae, the proximal one extending from base of cercus to proximal base of ventral tooth, and the second one starting from near ventral apex of ventral tooth and ending close to lateral tubercle after short attenuation ( Fig. 3B , cf. also Fig. 4E ); presence of a weak and short ventro-medial carina extending from the level of distal part of ventral tooth (but not connected to this structure) to the base of the ventral bulging (thus extending of about 1.5/10 of the cercus length). In lateral view, transition from anterior concave part to posterior convex part of ventral margin of cerci situated distinctly proximal to lateral tubercle/distal end of second lateral carina ( Fig. 3B ). Distal half of cerci without dense brush of long setae (pilosity made by regularly distributed setae) ( Fig. 3 ). Epiproct (inferior anal appendage) about 3/4 length of cerci, blackish to dark brown, thin and triangular in ventral or dorsal view and with apical margin shortly truncated, slightly bilobed due to tip curved upwards, and forming a short acute ridge ( Fig. 3 ).

Holotype measurements (mm). Total length (including anal appendages) 40.1, eyes contact c. 0.9, FW length 26.0, HW length 25.1, FW pterostigma 1.7, HW pterostigma 1.8, pro-/meso-/metathoracic legs length (including coxa and trochanter) 10.7/12.7/15.6, metatibia length 5.6, abdomen length (including anal appendages) 29.2, superior anal appendages (cerci) 1.8, inferior anal appendage (epiproct) 1.2, abdomen width at S2 2.2, at median part of S4 (minimal width) 1.1, at posterior margin of S7/anterior margin of S8 2.3 (maximal width) (slightly laterally compressed due to mode of preservation).

Variations in paratype and complement of description

State of preservation. Medium due to its mean of collect using a canopy interception trap with collector container filled with low salinity water (heavy rains) and, in spite of care, due to difficult transport of recipient from collecting point to base camp. Left prothoracic leg, right prothoracic tarsus, right mesothoracic tibia and tarsus and left metathoracic tarsus missing; parts distal to Pt missing or damaged in all wings; apex of right cercus broken.

Head. Frons with lower margin brownish orange and with upper and dorsal parts with strong copper to green metallic reflections (depending of light incidence). Vertex dark brown with strong green metallic and light copper reflections (depending of light incidence). Eyes in contact over a slightly shorter distance dorsally of c. 0.8 mm ( Fig. 4A ).

Thorax. Metathoracic tibial keel 81-82%.

Wings. Distal half of left HW aberrant. General coloration hyaline with very light dirty grayish saffron tinge. FW antenodal crossveins 10 of first rank and 10 of second rank; FW antenodals of first rank aligned or sub-aligned with those of second rank except for the two more distal ones on right FW. Gap separating Ax1 and Ax2 only slightly greater than gaps separating other antenodals. FW postnodal crossveins 6. Base of sectors of arculus at level of Ax 2 in FW. Mspl rather weak and poorly defined and covering one row of 3 cells in FW and HW. Anal loop with 13-14 cells. Anal loop and posterior wing margin separated by 2 rows of cells except on left wing where posterodistal part of anal loop is separated by one cell from wing margin.

Abdomen. Penis almost identical to that of holotype except for the remarkable presence of a third short, very thin and somewhat straight flagellum having its base close to right side of the base of strong median flagellum ( Fig. 4 B-D, see text below). Epiproct reaching basal 9⁄10 of the cercus length [this distinct difference with holotype is very probably due to the strong and probably artificial bent of S10, compare Fig. 3B with Fig. 4E ].

Description of the S7 pilose complex ( Fig. 4F )

Presence at distal 6/10 of the sternite of a kind of large tubercle bearing long, straight and caudad directed setae implanted on postero-dorsal surface. This tubercle connected to 4 carinae: 1) an anterior one occupying about 1.5⁄10 of the sternal length and strengthening distally; 2) two lateral ones, weak and slightly oblique and bearing on posterior margin a row of caudad directed setae decreasing in length toward lateral extremities; and 3) a posterior one well defined on about 0.5⁄10 of sternal length and distally progressively weakening to a rounded fold before vanishing. At about distal 8/10 of sternite presence of a transversally elongated low subtriangular tubercle of granular aspect (insertion of setae) delimited anteriorly by a thin transversal groove and bearing long, straight and caudad directed setae. Pleural membrane at level of distal pilose tubercle, with a brush of long straight medio-caudally directed setae.

Comparison of the vesicae spermalis

The penis of the two specimens are almost identical except for the presence in the paratype of an additional third small flagellum placed between the two usual ones. This flagellum appears more cylindrical in ethanol and its bifid apex is hardly visible, once dried it appears, as the other flagella, somewhat flattened, and the bifid apex appears more clearly ( Fig. 4B ). The presence of a third flagellum within the genus was never reported before. Its unique presence in the paratype is remarkable and somewhat mysterious. As the paratype seems to be a submature (penis less sclerotized, wings less tinged, and body colors less pronounced), we assume that this small flagellum could be cut by autotomy during mating and could prevent sperm removing by other males. It is also possible that this flagellum is the result of a teratologic or atavistic process (the sister genus Metaphya Laidlaw, 1912 exhibits five processes at apex of the penis, see remark 1 below). Complementary study and more material are needed to try to answer to this riddle.

Paratype measurements (mm). Total length (including anal appendages) 39.5, FW length 28.0, HW length 26.5 (estimation, post-Pt missing), FW pterostigma 1.8 (at C and RA veins), HW pterostigma 1.75 (at C and RA veins), pro/ meso-/metathoracic legs length (including coxa and trochanter) – (incomplete)/12.7/15.5, metatibia length 5.6, abdomen length (including anal appendages) 27.0, superior anal appendages (cerci) 1.9, inferior anal appendage (epiproct) 1.7, abdomen width at S2 2.4, at median part of S4 (minimal width) 1.1, at posterior margin of S7/anterior margin of S8 2.8 (maximal width).

Figures

FIG. 1. — Navicordulia pascali n. sp., holotype: A, general habitus; B, head in dorsal view and part of thorax in right lateral view.Scale bars:A,10 mm;B,1 mm.

FIG. 2. — Navicordulia pascali n. sp., holotype: A, wings in ventral view; B, base of left HW in ventral view; C, S2 secondary genitalia in left lateral view; D, vesica spermalis in left lateral view (removed from ethanol and air dried); E, distal segments of the vesica spermalis in left lateral view (removed from ethanol and air dried); F, distal segments of the Vesica spermalis in right lateral view (removed from ethanol and air dried); G, distal part of the first segment and distal segments of the vesica spermalis in ventral view (removed from ethanol and air dried). Scale bars: A, 10 mm; B, D-G, 0.5 mm; C, 1 mm.

FIG. 3. — Navicordulia pascali n. sp., holotype: A, S10 and anal appendages in dorsal view; B, part of S9, S10 and anal appendages in left lateral view. Scale bars: 1 mm.

FIG. 4. — Navicordulia pascali n. sp., paratype: A, top of the head showing the eyes seam; B, vesica spermalis in ventral view (removed from ethanol and air dried): distal part of the first segment and distal segments; arrow indicates the third flagellum; B’, detail of same with artificially colored third flagellum; C, vesica spermalis in ventral view with a slight lateral component (in ethanol). Arrow indicates the third flagellum; D, distal part of the vesica spermalis in ventral view (in ethanol). Arrow indicates the third flagellum; E, S9, S10 and anal appendages in right lateral view; F, S7 and S8 pilose complex: ventral view; F’ schematic longitudinal cut (lateral view, ventral part above). Scale bars: A, B, E, F, 1 mm.