Nesocordulia odonator Bernard, Daraż, Ravelomanana & Dijkstra, 2025

Bernard, Rafał, Daraż, Bogusław, Ravelomanana, Andrianjaka & Dijkstra, Klaas-Douwe B., 2025, Six new species of Nesocordulia McLachlan, 1882 reveal an insular evolutionary radiation of dragonflies on Madagascar (Odonata: Anisoptera: Libelluloidea), Zootaxa 5660 (2), pp. 151-193 : 166-168

publication ID	https://doi.org/10.11646/zootaxa.5660.2.1
publication LSID	lsid:zoobank.org:pub:103B00A2-9573-45C1-B1AE-A1FA9772E247
DOI	https://doi.org/10.5281/zenodo.16602860
persistent identifier	https://treatment.plazi.org/id/B042BE13-FF97-AA65-71DD-57CAFF33FBD7
treatment provided by	Plazi
scientific name	Nesocordulia odonator Bernard, Daraż, Ravelomanana & Dijkstra
status	sp. nov.

Treatment

Nesocordulia odonator Bernard, Daraż, Ravelomanana & Dijkstra sp. nov. —Crabshear Knifetail

Figs 7 View FIGURE 7 , 15–19 View FIGURE 15 View FIGURE 16 View FIGURE 17 View FIGURE 18 View FIGURE 19

http://zoobank.org/ urn:lsid:zoobank.org:act:38D61DF9-F45D-4327-B6C1-79955AA5C3FD

Etymology. The name, a noun in apposition, like those for Syncordulia legator Dijkstra et al., 2007 , Syncordulia serendipator Dijkstra et al., 2007 , and Syncordulia venator ( Barnard, 1933) , honours the explorers of Odonata . This species and N. fossa were found on the same day of Odonatours’ inaugural trip, whose participants sponsored the first introduction to Malagasy Odonata ( Dijkstra & Cohen 2021) .

Type material. Holotype male ( RMNH.INS.1552537), Rianasoa trail, 18.832° S, 48.435° E, 980 m asl (coordinates and altitude approximate), Mantadia National Park, Alaotra-Mangoro Region, Madagascar, 17.01.2016, leg. K.-D.B. Dijkstra and A. Ravelomanana. GoogleMaps

Diagnosis. Fairly large Nesocordulia species with unique hamule, in lateral view recalling a crab’s pincer (chelate appendage) with an almost spike-like dactyl, and unique labium with brown median lobe and mostly yellow lateral lobes. Only N. ipsio is similarly dark, sharing the limited thoracic yellow pattern of small spots, divided yellow lateroventral marking on S2, laterally long but discontinuous yellow ring on S7, and dark epiproct. N. ipsio has an even darker labium and cerci, however, and is also significantly smaller.

Description. Holotype male. Total length 54.5, abdomen (excluding appendages) 38.4, Fw 38.1, Hw 37.0, Fw Pt 1.9, cerci 2.3. Fw Ax 13–14, Fw Px 9–10, Hw Ax 8, Hw Px 10–11. Colouration generally dark, mostly black and metallic green, with yellow pattern ( Fig. 7a View FIGURE 7 ).

Head. Face dark, richly metallic with an olive yellow rectangular centre ( Fig. 7e View FIGURE 7 ). Vertex metallic with violet and blue reflections. Frons metallic: blue and violet (postfrons), dark bronze (frontal shield of antefrons), and green and copper (frons sides) ( Fig. 7e View FIGURE 7 ). Clypeus largely olive-yellow, with metallic green sides with golden and copper reflections. Labrum glossy black ( Fig. 7e View FIGURE 7 ). Labium yellow with brown base (median lobe) and lateral lobes only narrowly dark along their inner borders ( Fig. 7b View FIGURE 7 ). Occipital triangle black. Postgenae black. Eyes in life purple brown anterodorsally and blue posteroventrally ( Fig. 7a View FIGURE 7 ).

Thorax. Synthorax mostly metallic (green, blue and purplish-dark brown), with some non-metallic brown areas anteriorly and small yellow spots ( Figs 7a,b View FIGURE 7 ). Mesepisternum with metallic green and blue reflections in the upper half and non-metallic brown in the lower half. Mesokatepisternum yellowish brown. Synthoracic sides with four yellow spots in two lines ( Figs 7a,b View FIGURE 7 , 19 View FIGURE 19 ). In the upper line, a triangular mesepimeral spot opposite to the metastigma, and the uppermost rectangular metepisternal spot. In the lower line, two small spots along the lower margin of the synthorax, on the metakatepisternum below the metastigma and on the metepimeron. The metepimeral spot much less than half as long as the posterior border of metepimeron and not reaching poststernum. Poststernum dark brown ( Fig. 7b View FIGURE 7 ).

Wings. Membrane tinted with yellow basally ( Fig. 7b View FIGURE 7 ). Pt short, brown ( Fig. 7c View FIGURE 7 ). Membranula dark brown.

Abdomen. Black with paired yellow pattern ( Fig. 7a View FIGURE 7 ). The laterodorsal yellow spots on each side of S2 are of different size: the anterior spot broad, with tapered tip pointing dorsally, and the posterior one small and angular ( Fig. 7a View FIGURE 7 ). The lateroventral yellow marking on each side of S2 divided into two small well-separated spots ( Figs 7b View FIGURE 7 , 16d View FIGURE 16 ). The laterodorsal yellow pattern on S3–6 consists of anterior stripes on each segment and posterior stripes on S3 and S4 only (the last one vestigial) ( Fig. 7a View FIGURE 7 ). S7 with a basal dorsolateral yellow ring covering one fifth of the segment’s length and not reaching the supplementary transverse carina; the ring is extended far laterally and slightly broadened dorsally ( Fig. 7a View FIGURE 7 ), where it is divided by a broad black line along the dorsal carina ( Fig. 7f View FIGURE 7 ). The yellow line along the ventral carina ( Fig. 7d View FIGURE 7 ): (a) on S3–6, continuous and not broadened anteriorly on each segment; (b) on S7, partly broadened into a yellow stripe turning into brown distally; (c) on S8, present in its anterior half and broadened into a brownish yellow spot also visible in lateral view.

Secondary genitalia. In lateral view, the hamule large with two finger-like branches, deeply and narrowly separated and distinctly narrowed and pointed; the posterior branch is much shorter and thinner ( Figs 7b View FIGURE 7 , 15 View FIGURE 15 ). In ventral view, the anterior branch L-shaped with a relatively short and narrow inner lobe ( Fig. 16d View FIGURE 16 ). Genital lobe black, basally yellow, with black hair-like setae. In lateral view, it is directed downwards and relatively broad and short ( Figs 7b View FIGURE 7 , 15 View FIGURE 15 ), while in ventral view more elongated, with a narrow, finger-like tip ( Fig. 16d View FIGURE 16 ); this apical part is bent parallel to the body towards the opposite genital lobe and therefore is not visible in the foreshortened lateral view.

Caudal appendages. Cerci fairly short, yellowish, basally black up to 40% of the length, with mostly pale hair-like setae not contrasting with the background ( Fig. 7g View FIGURE 7 ). In dorsal view, almost straight on the two thirds of the length and further bent outwards and slightly tapering distally ( Fig. 18 View FIGURE 18 ). In lateral view, with lower margin shallowly arched up, and then gently bent at 60% of the length and further straight, appearing thus in their distal half at first slightly distended and then tapering ( Figs 7g View FIGURE 7 , 17 View FIGURE 17 ). Epiproct dark brown and long, reaching 85% of the cerci length ( Figs 7g View FIGURE 7 , 17 View FIGURE 17 ).

Female. Unknown.

Distribution and ecology. Known only from the type locality in central-eastern Madagascar ( Fig. 21 View FIGURE 21 ), in the ecoregion of Madagascar Humid Forests ( One Earth 2024) and the hydrographic ecoregion of Eastern Highlands ( Sparks & Stiassny 2022). The only known specimen was flying over a fairly large and rocky but very shady forest stream.