Heteragrion cyane Machado & Souza, 2014

(Figs. 28a–d)

[Key locator: Key to Group A species, couplet 10 (9)]

Heteragrion obsoletum: Souza et al. 2013: 1369 (misidentification; mention of specimen in checklist as H. obsoletum).

Heteragrion cyane: Machado & Souza 2014: 95–99 (description and diagnosis of ♁; discussion on species with blue coloration; figs. 1–6);— Lencioni 2017: 139–140 (general taxonomic information; distribution; fig. 65);— Vilela et al. 2019b: 591–593 (comparison with H. denisye and original description of H. obsoletum; figs. 4f–h);— Cezário & Guillermo-Ferreira 2021: 78–86 (comparison with Heteragrion “blue species”).

Material examined. 1♁ (HOLOTYPE) BRAZIL, Minas Gerais state, Barroso, Mata do Baú, 27.iii.2010, (- 21.1869, -43.9761, centroid), M.M. Souza leg., ABMM .

Known distribution. Brazil (Southern Minas Gerais state).

Diagnosis and remarks. Heteragrion cyane is one of the “blue species” of Group A, along with H. denisye and H. gorbi . This species is poorly known, being described from a single male (Machado & Souza 2014), with very few specimens found after its description (Walter Ávila pers. comm.). For this reason and for inhabiting an area threatened with deforestation, its conservation status has been assessed as Vulnerable by the IUCN Red List (Cano-Cobos & Lozano 2021). The following character combination distinguishes this species from the remainder of Group A species: overall body coloration consisting of shades of blue and green, with black background (Figs. 28a–b); ML ridge not reaching its apex (Fig. 28c); ML apex rounded (Figs. 28c–d).