Heteragrion flavidorsum Calvert, 1909

(Figs. 33a–g)

[Key locator: Key to Group B species, couplet 25 (23’)]

Heteragrion flavidorsum: Calvert 1909: 111–112 (description of ♁ from Bolivia; comparison with H. inca and H. aequatoriale; plate III fig. 41);— Williamson 1919: 35 (key to species, ♁ in couplet d1; brief comment on the type specimen, not examined by him; figs. 41, 108, 155);— Hartung 2002: 191 (comparison with H. palmichale);— Garrison et al. 2010: 88, 91 (list of Heteragrion species; figs. 389–390, 396 as H. speciosum);— Stand-Pérez et al. 2019: 92–93, 104–106 (first time recorded to Colombia; table 1; key to species, ♁ in couplet 3, ♀ in couplet 4’; remarks and ♀ description; figs. 5g –h, 9g –i, 14d–f, 16g, k, 19).

Heteragrion speciosum: Sjöstedt 1918: 7–8 (description of ♁ from Peru; comparison with H. aequatoriale and H. angustipenne; plate 1 fig. 13, plate 2 fig. 14);— Williamson 1919: 64 (mentions inconsistencies on Sĵstedt’s description; mentions a possible synonymy with H. aequatoriale);— Paulson 1981: 303 (comparison of coloration patterns with other Heteragrion species);— De Marmels 1987: 231 (examines the ♁ holotype, proposes the synonymy with H. flavidorsum; additional observations; figs. 20–24, 49).

Material examined. 1♁ BRAZIL, Rondonia state, Rio Pardo, 5-10.xi.1989, (-10.8333, -63.1166, 187m asl), R.W. Garrison leg., ABMM ; 18♁♁ COLOMBIA, Putumayo Department, Mocoa Municipality, Serraníade los Churumbelos National Park, 20.i.2013, (1000m asl), L. Pérez & J. Montes leg., UARC ; 5♁♁ Putumayo Department, Orito Municipality, Isla Escondida Natural Reserve, 12.iii.2017, (0.6578, -77.0722, 850m asl), M. Vigano, A. Corso & O. Janni leg., CEUA ; 3♁♁ road to Nuevo Mundo island, 7-8.i.2017, (0.6613, -77.0767, 890m asl), M. Vigano, A. Corso & O. Janni leg., CEUA .

Synonyms. Heteragrion speciosum Sj ̂stedt, 1918 (De Marmels 1987).

Known distribution. Bolivia, Brazil (Rondônia state), Colombia (eastern Andean foothills and Amazon) and Peru.

Diagnosis and remarks. The IUCN Red List assessment of H. flavidorsum classifies this species as Data Deficient, as “much confusion surrounds its taxonomy and distribution” (Hoffmann et al. 2016). We consider this assessment outdated, as since this assessment was published Stand-Pérez et al. (2019) discovered this species to Colombia, providing additional information on its taxonomy and distribution. The following character combination distinguishes this species from the remainder of Group B species: ridge above ML nearly straight, with two parallel rows of teeth, one being very short (Fig. 33c); ML apex blunt (Fig. 33g) or acute (Figs. 33c–e); in dorsal view, MP-AP junction not marked, nearly straight (Fig. 33f).