Oxystigma

Garrison, Rosser W., 2014, Review of Oxystigma Selys with the synonymy of Oxystigma williamsoni Geijskes (Odonata: Heteragrionidae), Zootaxa 3780 (2), pp. 347-364: 349-350

Key to males of Oxystigma  Edit

1. Cercus in medio-dorsal view with supplementary denticulate ridge extending to basal 0.30 ( Figs. 41–42), transverse ridge present on medial lobe ( Figs. 41–42); distal portion of cercus beyond posterior margin of medial lobe short, about 0.30 of cercus ( Fig. 42; A> B); larger species, HW ≥24.0 mm; Sierra de Lema region, Bolívar State, Venezuela ( Fig. 58)........ caerulans  Edit

1 '. Cercus in medio-dorsal view with denticulate ridge extending to basal 0.50, transverse ridge absent on medial lobe ( Figs. 43– 57; vestigial in some O. petiolatum  Edit from Rondônia State, Brazil, Fig. 56 b); distal portion of cercus beyond posterior margin of medial lobe long, about ≥ 0.45 of cercus ( Fig. 43; A ≈ B); smaller species, HW ≤24.0 mm; widespread in northern and central

South America ( Fig. 58)................................................................................ 2 2 (1 '). Frons, clypeus and labrum light blue ( Figs. 2–3); synthorax in mature male largely black or dark brown above ( Figs. 17–18); cercus in dorsal view with transverse ridge prominent and not reaching posterior margin of medial lobe ( Figs. 49–51)................................................................................................... cyanofrons  Edit

2. Frons, clypeus and labrum mottled with black spots on a pale blue or yellow underground or largely dark to shining black, ( Figs. 6–14); synthorax in mature male black or dark brown above, with pale dorsal or humeral stripes ( Figs. 21–23); cercus in dorsal view with transverse ridge extending posteriorly beyond medial lobe ( Figs. 52–54) or to medial lobe posterior margin ( Fig. 55) or (populations from Ecuador and Rondônia State, Brazil) disappearing ventro-posteriorly, not forming a prominent ridge ( Figs. 56–57)............................................................................ petiolatum  Edit

Figures

FIGURE 58. Distribution of Oxystigma.

FIGURES 41 – 48. Right male cercus, medio-dorsal (internal) view

FIGURES 49 – 57. Right male cercus, dorsal view (A), postero-mesal view (B)

FIGURES 1 – 8. Head, anterior (frontal) view.

FIGURES 17 – 24. Thorax latero-dorsal view.