Abstract
Nesocordulia McLachlan, 1882 is a poorly known dragonfly genus endemic to Madagascar and the Comoros. The genus is revised, and all twelve species are described, including six new ones: N. coloratissima sp. nov., N. evanida sp. nov., N. fossa sp. nov., N. ipsio sp. nov., N. lyricauda sp. nov., and N. odonator sp. nov. All are well-defined, with notably distinct male cerci, hamules, and colouration. While an identification key for males of all species is provided, this is based on single specimens for six of them. Females are known for only six species. While several radiations of damselfly genera had been recognised in the Malagasy Region already, Nesocordulia is the first to be uncovered in the suborder Anisoptera. Due to the scarcity of data, the exact drivers of their diversification remain unclear, however. While seven species are known from the humid and subhumid forest zone of eastern and north-western Madagascar, and only N. coloratissima and N. villiersi Legrand, 1984 appear confined to the drier west and to the Comoros respectively, the exact collection localities of three species remain unknown. Although the limited data suggest that most species are localised, the few species with more records appear to be fairly widespread. The species’ ecology is almost unknown, with more details provided on the habitat and behaviour of N. evanida only, and their conservation status is also largely unknown. Four species have not been recorded for over a century, however, while only N. coloratissima and N. evanida were confirmed to inhabit anthropogenically influenced landscapes.
Odonata, Corduliidae s.l., systematics, species description, taxonomic synopsis, biogeography, endemic species, Malagasy Region, Comoros
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Nesocordulia coloratissima sp. nov.
(a) male habitus in lateral view; (b) female habitus in dorsal view; (c) male s6–8 in dorsal view; (d) male abdomen in ventral view; (e) male head in frontal view (f) male head in ventral view; (g) male terminalia in lateral view.
Photos by: a–b, Allan Brandon; c–g, Bogusław Daraż. |
Nesocordulia coloratissima Bernard, Daraż, Ravelomanana & Dijkstra sp. nov.
—Flame-tipped Knifetail
Etymology. a declinable feminine latin adjective, formed from colorata- plus superlative suffix -issima, “the most colourful”. this is the most variegated species, with a striking spectrum of black, rusty brown, yellow, and white, as well as metallic with green, blue, golden, bronze, and violet reflections.
Diagnosis. This rather small Nesocordulia species is the most colourful and extensively yellow-marked in the genus. the black abdomen marked with yellow up to the base of d7, while the remainder is uniformly rufous, is unique, as are the yellow occipital triangle, yellow frons sides, broadly yellow centre of labrum, and the especially large yellow spot on the mesepimeron and metepisternum (sometimes narrowly divided into two large triangular spots but more frequently fused). the hamule and cerci are also unique (see figs 15–16 and 17–18, respectively), although the former is similar to that of N. evanida.
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Nesocordulia evanida sp. nov.
(a) male habitus in lateral view; (b) female habitus in lateral view; (c) male head and thorax in dorsal view; (d) male secondary genitalia in lateral view; (e) male habitus in ventral view; (f) male abdomen in dorsal view; (g) male head in frontal view; (h) male terminalia in lateral view.
Photos by Bogusław Daraż. |
Nesocordulia evanida Bernard, Daraż & Dijkstra sp. nov.
—Little Knifetail
Etymology. a declinable feminine latin adjective meaning “vanishing from sight”, as males are almost impossible to follow for the observer’s eyes due to the combination of their behaviour, disruptive camouflage, and the dappled light in their microhabitat.
Diagnosis. The smallest Nesocordulia species, separated from its probable closest relatives (N. coloratissima and N. malgassica) by the black rather than rufous s7–10 and its slightly, but distinctively distended cerci with black hair-like setae. differs from other black-tailed species by the shape of the cerci and hamule, as well as the thoracic markings with two triangular and three roundish yellow spots on each side.
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Nesocordulia fossa sp. nov., male.
(a) habitus in lateral view; (b) head in ventral view and thorax and s1–2 in lateral view; (c) terminalia in dorsal view; (d) abdomen in ventral view; (e) head in frontal view; (f) left Hw.
Photos by: a, Dave Smallshire; b–f, Bogusław Daraż. |
Nesocordulia fossa Bernard, Daraż, Ravelomanana & Dijkstra sp. nov.
—Fossa Knifetail
Etymology. the name, a noun in apposition, refers to madagascar’s largest carnivore, the similarly rufous, long-bodied and enigmatic Fossa (Cryptoprocta ferox Bennett, 1835).
Diagnosis. Comparatively large species, easily separated from all congeners except N. rubricauda by the reddish brown body, dark brown wing bases, and denser venation, especially between the cubital and anal veins. Aside from unique features, such as the shape of the cerci and hamule (see figs 15–16 and 17–18, respectively), yellow markings on the largely reddish brown thorax, and black apical smudges laterally on the reddish brown s3–6, differs from N. rubricauda by the yellow marking on the clypeus and the single cell rows subtended by Rspl.
Nesocordulia ipsio Bernard, Daraż & Dijkstra sp. nov.
—Dark Knifetail
Etymology. the name, a noun in apposition, refers to the CEPF project Insects and People in the Southern Indian Ocean (IPSIO), initiated by Brian fisher at the madagascar Biodiversity Center. K.-D.B. Dijkstra participated in the IPSIO expedition to marojejy national Park, but all specimens were collected by alan gardiner while he was seeking for butterflies.
Diagnosis. Medium-sized Nesocordulia species with a uniquely shaped hamule (see fig. 15) and the most extensive and contrasting dark markings on the labium and cerci in the genus. Only the presumably closely related N. odonator is similarly dark, sharing the limited thoracic pattern of small yellow spots, divided yellow lateroventral marking on S2, the laterally long but dorsally interrupted yellowish basal ring on S7, and dark epiproct. Nesocordulia ipsio differs from it, however, by a different hamule (see figs 15 and 16) and mostly blackish brown lateral lobes of labium, and is also significantly smaller.
Nesocordulia lyricauda Bernard, Daraż & Dijkstra sp. nov.
—Lyre-tipped Knifetail
Etymology. a feminine noun derived from latin “cauda”, a tail, and “lyra”, an u-shaped instrument with two curvy branches, to describe the distinctive lyre-shaped cerci in dorsal view.
Diagnosis. the largest Nesocordulia species, separated by its unique long lyre-shaped cerci, large and uniquely shaped hamule (see fig. 15), and the basal yellow spots uniquely extending both dorsally and laterally on s7. also has more Px in Fw (11–13 vs. 7–10) and Hw (13–14 vs. 7–11) than other black species.
Nesocordulia odonator Bernard, Daraż, Ravelomanana & Dijkstra sp. nov.
—Crabshear Knifetail
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).
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.
Rafał BERNARD, Bogusław DARAŻ, Andrianjaka RAVELOMANANA and Klaas-Douwe B. DIJKSTRA. 2025. Six New Species of
Nesocordulia McLachlan, 1882 reveal an insular Evolutionary Radiation of Dragonflies on Madagascar (Odonata: Anisoptera: Libelluloidea).
Zootaxa. 5660(2); 151-193. DOI:
doi.org/10.11646/zootaxa.5660.2.1 [2025-07-09]
