Oxystigma

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

Key to females of Oxystigma

Specimens may need to be relaxed and subsequently dried with the prothorax pushed anteriorly from the synthorax in order to examine the intersternite and setifer.

1. Dorsal tip of setifer ending in the form of a club, extending only a little beyond dorsal margin of intersternite ( Fig. 26 ); irregular rounded sclerite above intersternite absent or poorly developed; Sierra de Lema region, Bolívar State, Venezuela ( Fig. 58 ) caerulans

1'. Dorsal tip of setifer digitiform ( Figs. 31–34 ) to acute ( Figs. 27–30 ), extending well beyond dorsal margin of intersternite; with an irregular rounded sclerite above intersternite that may be partially hidden by dorsal arm of setifer; widespread in northern and central South America ( Fig. 58 )....................................................................... 2

2(1'). Dorsal tip of setifer forming an acute process abruptly curving anteriorly away from margin of mesepisternum ( Figs. 27–30 )............................................................................................. cyanofrons

2. Dorsal tip of setifer forming a linear digitiform process, not abruptly curving anteriorly from mesepisternum ( Figs.25, 31–34 )............................................................................................ petiolatum

Figures

FIGURE 58. Distribution of Oxystigma.

FIGURES 25 – 34. Female intersternite and setifer (mesopresternum), left lateral view.