Cordulegaster virginiae, Novelo-Gutiérrez, 2018

Novelo-Gutiérrez, Rodolfo, 2018, Cordulegaster virginiae sp. nov. from Mexico, including a comparison with C. diadema Selys, 1868, and a redescription of its larva (Odonata: Cordulegastridae), Zootaxa 4394 (3), pp. 371-382 : 372-376

Cordulegaster virginiae sp. nov.

( Figs. 1–9)

Holotype. ♂ ( IEXA), MEXICO: Veracruz; Municipality of Banderilla , La Martinica ( 19°35’22.14” N; 96°57’13.28” W), elevation 1550m asl, stream in cloud forest, 16 September 2001, R. Novelo leg.

Allotype. ♀ ( IEXA), same data as holotype but Municipality of Xalapa , Xalapa ( 19°30’47.05” N; 96°56’29.20” W), elevation 1336m, stream in cloud forest, 23 September 2017, R. Novelo leg . Holotype and allotype deposited in IEXA.

Paratypes. 6♂; 1♂ same data as holotype, deposited in RWG ; 5♂ same data as allotype but 30 September 2016, J.A. Gómez, M. Torres leg., deposited in IEXA.

Etymology. This species is dedicated to Virginia García-Castillo (a noun in the genitive case), for her invaluable collaboration collecting odonates throughout Mexico.

Description of holotype. Very large ( 93 mm total length, body blackish-brown, pterothorax with large yellow bands, abdomen mostly blackish-brown with narrow, subbasal yellow rings on S2 – 8, caudal appendages relatively short ( Fig. 1).

Head. About twice as wide as long, labium creamy pale without dark markings; basal half of mandibles yellowish-brown, apical half mostly reddish-brown, tips black; labrum light brown; anteclypeus brown, postclypeus mostly brown with a transverse, basal, yellow stripe not reaching lateral margins, inferior border carinated; frons dark brown ( Fig. 1), anterior surface subtrapezoid and rimmed, concave dorsally; antennae blackish-brown; vertex black, ocelli yellow; occiput dark brown with a crest with blackish setae; rear of head light brown, tumid. In life compound eyes emerald green, in contact dorsally by about 0.5 mm.

Thorax. Anterior and middle lobes of pronotum light brown, an anterolateral, rectangular, yellow spot on each side of middle lobe, posterior lobe blackish-brown, bent posteriorly, propleuron yellowish-brown. Pterothorax ( Fig. 1) mostly reddish-brown; anterior collar brown; dorsal carina reddish-brown; yellow stripes on pterothorax as follows: first antehumeral stripe wedge-shaped, short, inferior end terminating far from anterior collar, upper end close to antealar crest but not touching it; second antehumeral stripe vestigial, forming an ill-defined small spot at upper 1/10; mesepimeral stripe narrowing gradually ventrally, covering 9/10 the length of mesepimeron, not touching antealar crest at upper end; metepisternal stripe reduced to a small spot at upper 1/10; metepimeral stripe covering the full-length of metepimeron, wide and parallel-sided; venter of thorax light brown. Legs: procoxae yellowish, meso- and metacoxae light brown; trochanters, tibiae and femora reddish-brown with distal ends black ( Fig. 2); tarsi black; pretarsal claws reddish-brown with distinct supplementary tooth; armature black, as follows: spines small and stout on ventral surfaces of femora; protibiae with modified scale-like spines on distal half of internal border, meso- and metatibiae with short, subquadrate spines on internal borders ( Fig. 2), long slender spines on external borders; tarsi with long slender spines. Wings hyaline, tinged with brown ( Fig. 1) mainly on distal half. Venation dark brown, costal edge yellow. Basal subcostal crossvein absent; second primary antenodal crossvein the 7th (left), the 8th (right) on Fw, 6th (left), the 7th (right) on Hw. Antenodal crossveins: Fw 22 (left), 21 (right); Hw 12 (left), 14 (right). Postnodal crossveins: Fw 16 (left), 17 (right); Hw 17. One cubito anal crossvein in addition to inner side of subtriangle in all wings. Supratriangles free, with one crossvein on right Fw; subtriangles one-celled, triangles two-celled. Anal loop with 5 cells, anal triangle with 3 (left) and 4 (right) cells. Pterostigma dark brown, narrow, without brace-vein, covering about 3.6 (left), 3 (right) cells in Fw, 3.4 (left), 3.8 (right) cells in Hw.

Abdomen. Predominantly blackish-brown ( Fig. 1), S1 brown; S2 mostly blackish dorsally, brown laterally with a transverse, dorsal yellow band just behind of transverse carina, auricles yellow with apical denticles black, small and blunt, inferior margin of tergum with a row of small black denticles on apical 6/10; S3–8 blackish-brown with a transverse yellow band just behind of transversal carinae interupted at middorsal line; S9–10 blackish-brown without pale markings, a basodorsal, circular, shallow depression to each side of middorsal line on S10 ( Fig. 3). Abdomen wide at S1–2 ( 6.5 mm including auricles) then abruptly narrowing at basal 1/3 of S3 ( 1.8 mm), distal 2/3 of S3 and S4–5 slender, S6 widening gradually reaching a maximum width on S7 (6.0 mm), then tapering to posterior margin of S10 ( 2.7 mm). Accessory genitalia ( Figs. 4–6): Anterior hamule, in ventral view, with medial margin sigmoid ( Fig. 4), external surface convex anteriorly, with a large, wide, deep, longitudinal furrow posteriorly ( Figs. 5–6), internal surface strongly concave; in lateral view with posterior margin widely rounded ( Figs. 5–6). Posterior hamule long, slender, roundly pointed ( Fig. 6), directed postero-medially ( Fig. 4); in lateral view with a longitudinal furrow on basal 0.35 ( Fig. 6). Genital ligula reddish ( Fig. 4), strongly curved inwards dorsoventrally, with a strong, sharp, longitudinal, median keel along its basal half, lateral margins carinate on basal 0.45, apex truncate at middle ( Fig. 4) with a large rounded lobe on each side and produced laterodorsally ( Fig. 4). Vesica spermalis ( Figs. 4, 7): V1 light reddish- brown ( Fig. 4); V2 completely wrapped by genital ligula, blackish-brown and incurved, with a large, dorsal, ‘hump’ ( Fig. 7); V3 black, short with a bifid ventral process roundly pointed ( Fig. 7); V4 (glans) as a dorsal inflated pouch, posterior surface produced as a large, flattened nozzle ( Fig. 7); a dorsolateral lobe covered with minute golden setae on each side ( Fig. 7). Caudal appendages: Cercus reddishblack ( Figs. 3, 8), short, as long as middorsal length of S10; in dorsal view ( Fig. 3) parallel-sided, ending abruptly in a short, acute, oblique tip; in lateral view a lateral, longitudinal carina on apical 0.80 ( Fig. 8a,), ventral margin concave basally, convex distally, with a large, basal, hook-like tooth and a smaller medial tooth on basal 0.40 ( Fig. 8a); in dorsolateral view as in Fig. 8b. Epiproct light brown ( Figs. 3, 8), subtriangular, gradually narrowing towards distal end, tip roundly truncate with a pair of subapical, dorsal, wide, toothed tubercles to each side of midline ( Figs. 3, 8a). Paraprocts with a median, strong, long spine directed caudally.

Measurements: TL, 93; AL, 70; FwL, 59; HwL, 57; HwW at level of nodus, 15; FwPtL, 4.0; HwPtL, 5.2; MWh, 12.3; HfL, 9.7; cercus (lateroventral), 3.3.

Paratypes variation. Head: Some individuals with a pair of small, subrectangular, median yellow spots close to basal margin on labrum. Thorax: Anterior collar brown to blackish-brown. Second primary antenodal crossvein the 8th on both Fw, 7th on left Hw, 8th on right Hw. Antenodal crossveins: Fw 19–22; Hw 12–15. Postnodal crossveins: Fw 15–17; Hw 14–18. Supratriangles free or with one crossvein (4 individuals out of 6 [60.6%] had at least one supratriangle crossed); anal loop with 4–5 cells. Pterostigma covering about 2.6–4 cells in Fw, 2.5–4 cells in Hw.

Measurements: N= 6, mean in square brackets; TL, 86–91 [88.3]; AL, 66–69 [67.5]; FwL, 55–58 [56.7]; HwL, 53–57 [55.5]; HwW at level of nodus, 14–15 [14.3]; FwPtL, 4–5 [4.6]; HwPtL, 4.8–5.8 [5.3]; MWh, 11.7–12.2 [12.0]; HfL, 7.27–9.4 [8.9]; cercus (lateroventral) 2.67–3.3 [3.0].

Description of female allotype. Mostly as described for holotype but larger ( 100 mm total length), with the following differences: Head: Labium light brown. Thorax: Anterior collar blackish-brown. Legs: trochanters and femora reddish-brown with distal ends black, tibiae and tarsi black; meso- and metatibiae with long, slender spines on internal and external borders. Wings (tip of left Fw broken and lost): second primary antenodal crossvein the 9th (left), the 7th (right) on Fw, 7th (left), the 6th (right) on Hw. Antenodal crossveins: Fw 25 (left), 19 (right); Hw 13 (left), 12 (right). Postnodal crossveins: Fw 16 (left), 15 (right). Supratriangles free; subtriangle 2-celled on left Fw. Anal loop with 6 cells (left), undifferentiated (right). Pterostigma light brown, narrow, covering about 3.2 (left), 3 (right) cells in Fw, 3.3 (left), 3.0 (right) cells in Hw. Abdomen: S1 light brown; inferior margin of tergum of S2 with 3–4 minute black denticles on apical 0.10; S10 without a basodorsal, circular, shallow depression to each side of middorsal line. Abdomen wide at S1–2 ( 7.2 mm) then gradually narrowing at basal 1/3 of S4 ( 3.5 mm), distal 2/3 of S4, S5 and basal 2/3 of S6 slender, distal 1/3 of S6 widening gradually reaching a maximum width on S7 ( 4.3 mm), then tapering to posterior margin of S10 ( 3.5 mm). Ovipositor ( Fig. 9): Very long, ventral gonapophyses dark reddish-brown, elongated, roundly tipped, as long as dorsal surface of S8+9+10, dorsal gonapophyses reddish, shorter, reaching basal 2/3 of ventral gonapophyses. Caudal appendages: Cercus black, short, 2/3 the middorsal length of S10; in dorsal view lanceolate, granulose; in lateral view flattened dorsoventrally, with a lateral, longitudinal carina on apical 0.80. Epiproct dark brown, triangular, abruptly narrowing towards distal end, densely covered by stout, stiff, black bristles.

Measurements: TL, 100; AL, 77; FwL, 62; HwL, 62; HwW at level of nodus, 18; FwPtL, 5.5; HwPtL, 6.0; MWh, 13.2; HfL, 9.5; ovipositor 10.0.

Diagnosis. Males of Cordulegaster virginiae sp. nov. are conspicuously larger ( 86–93 mm total length, N=7) than males of C. diadema ( 73–80 mm, N=6), and can be differentiated by the reduced yellow coloration, specially the lack of a basal pale ring on S9–10, although main differences are structural and located on abdomen as follows [features of C. diadema in square brackets]: External side of anterior hamule with a deep, longitudinal external furrow ( Fig. 6), with a transverse excavation on convex portion of hamule ( Fig. 5) [external furrow moderate, transverse excavation lacking or reduced on convex portion ( Fig. 10a)]; posterior notch on medial margin of anterior hamule widely rounded ( Fig. 5) [narrow, triangular in lateral view ( Fig.11a)]. Posterior hamule with an external, longitudinal furrow on basal 0.35 ( Fig. 5) [no furrow ( Fig. 10a)]. Middle part of apex of genital ligula truncate ( Fig. 4) [usually convex ( Fig. 11a), in a specimen from Panama (Bambito) it is truncate ( Fig. 11c)]. Lobes of posterior margin of segment 1 of vesica spermalis widely V-shaped ( Fig. 4) [more contiguous ( Fig. 11a)]. Ventral margin of tergum of S3 mostly smooth, sometimes with a few minute denticles [with a row of small black denticles]. Ventrally, epiproct wider at base with a proportion of 1:0.4; [wider at base than apex in a proportion of 1:0.7]; subapical, dorsal toothed tubercles separated each other by the same width of each tubercle or little more [subapical, dorsal toothed tubercles separated by more than twice the width of each tubercle]. The female of C. virginiae is also larger ( 100 mm total length, N=1) than those of C. diadema ( 74-81 mm, N=5).

Remarks. Adults of Cordulegaster virginiae sp. nov. were found inhabiting small, shaded, moderately perturbed streams of 2nd order, at middle altitudes ( 1336-1550m) in cloud forest. The only female found was caught flying over a large sandy reach at 13:44 h.