Minagrion, in Santos, 1965

Vilela, Diogo Silva, Anjos-Santos, Danielle, Koroiva, Ricardo, Cordero-Rivera, Adolfo & Guillermo-Ferreira, Rhainer, 2020, Revision of the genus Minagrion Santos, 1965 (Odonata: Coenagrionidae), Zootaxa 4786 (2), pp. 176-198 : 179

Key to males of Minagrion (cercus in mediodorsal view, except when otherwise indicated)

1. Larger species (54−61 mm total length), abdomen 2x longer than Fw length ( Fig. 1d)................. M. mecistogastrum

1’. Medium species (31−44 mm total length), abdomen less than 2x the length of Fw (as in Fig. 1b, e)..................... 2

2. Dorsal plate of cercus broad; ventrobasal portion only 1/5 of the cercus length ( Figs. 3 u−x, 8g−h); tubercle digit-like with a rounded apex ( Fig. 2k)......................................................................... M. waltheri

2’. Dorsal plate of cercus narrow (as in Fig. 3h, t); ventrobasal portion at least 1/2 of cercus length (as in Fig. 3t); tubercle never digit-like or with rounded apex.......................................................................... 3

3. Longitudinal ridge of cercus not entire (i.e. disrupted along its length) forming a basal and an apical ridge, more pronounced on the distal 1/2 ( Fig. 3l); sclerotized apex of cercus globose with no apparent teeth ( Figs. 3l, 8d); tubercle quadrangular with a slightly concave apex ( Fig. 2e)................................................................ M. canaanense

3’. Longitudinal ridge of cercus entire (i.e., a continuous ridge along its length, as in Fig. 3d, t); sclerotized apex of cercus not globose, with evident teeth; tubercle not as above............................................................ 4

4. Cercus shorter than S 10 in lateral view, ( Figs. 3 q–t, 8e–f) and with acute sclerotized apex, with one strong tooth ( Figs. 3t, 8e); tubercle triangular with acute apex ( Fig. 2i)........................................................ M. ribeiroi

4’. Cercus subequal in length to S 10 in lateral view, rounded sclerotized apex, with one strong tooth; dorsal portion of cercus broad at basal half, narrowing towards the base, ventrobasal portion roughly quadrangular, reaching 1/2 of cercus ( Figs. 3 a–h, 8a–b); tubercle quadrangular, with the excavated “beak-like” apex ( Fig. 2 a–b); genital ligula with a small inner fold at the flexure in lateral view, a pair of lateral sclerotized processes, and entire apex ( Fig. 4 a–b)............................ M. caldense