Dimeragrion species

Mendoza-Penagos, Cristian Camilo, Kenzy, Myckey, Gonçalves, Silva & Vilela, Diogo Silva, 2023, A new species of Dimeragrion Calvert, 1913 (Odonata: Zygoptera: Heteragrionidae) from Northwestern Brazil, Zootaxa 5318 (3), pp. 411-420 : 419

Additions to the key to males of Dimeragrion species provided by De Marmels (1999)

Modified to include D. baniwa as follows:

3(1). No accessory cross-vein besides CuP in cubito-anal space ( Fig. 1d ).............................................. 4

3’. At least one accessory cross-vein besides CuP in cubito-anal space. Male cerci with axe-shaped ventral-medial expansion truncated proximally................................................................................... 5

4(3). Male cerci with axe-shaped ventral-medial expansion prolonged proximal in a sharp angle. BP Tubercule well-developed.Apex of cerci acute in lateral view.................................................................. mesembrinum

4’. Male cerci with axe-shaped ventral-medial expansion straight forming a right angle ( Fig. 2b ). BP tubercule slightly developed ( Fig. 2b, c ). Apex of cerci rounded in lateral view ( Fig. 2 a−c)............................................. baniwa

5(3). Male cerci shorter than segment 10, sharply tapering towards pointed tip, in lateral view; dorso-basal tubercle higher than hind margin of segment 10......................................................................... unturanense

5’. Male cerci longer than segment 10, not sharply tapering towards obtuse tip, in lateral view; dorso-basal tubercle not obviously higher than hind margin of segment 10............................................................ percubitale

Figures

FIGURE 1. Dimeragrion baniwa. Holotype from Amazonas State, Brazil: (a) left view of habitus; (b) detail of head frontal view; (c) detail of head dorsal view; (d) hind wing; (e) S1–2 ventral view; (f) genital ligula ectal view; (g) genital ligula lateral view. Abbreviations: Flg, lateral flagella; Tf, terminal fold; VTb, ventral tubercle. Scale bar = 1 mm.

FIGURE 2. Dimeragrion baniwa male: (a) S10 in dorsal view; (b) S10 in dorso-lateral view; (c) S10 in lateral view. Abbreviations: BTb, basal tubercle Scale bar = 1 mm. Right cercus omitted on a and b.