Erythrodiplax castanea

Haber, William A., Wagner, David L. & Rosa, Carlos De La, 2015, A new species of Erythrodiplax breeding in bromeliads in Costa Rica (Odonata: Libellulidae), Zootaxa 3947 (3), pp. 386-396 : 393

Key to adults of the Erythrodiplax castanea group

modified from Borror (1942), Förster (2001), and Heckman (2006).

1. Transverse carina on S2 uniformly curved................................................... most Erythrodiplax

- Transverse carina on S2 nearly right-angled................................................. castanea group ... 2

2. Pterothorax with longitudinal bright cream or yellow stripe over dorsal carina extending only to end of dorsal carina, not enter- ing inter-alar space............................................................................... laselva

- Pterothorax without a longitudinal bright cream or yellow stripe over dorsal carina................................. 3

3. Thorax and abdomen black (may have gray pruinescence in old individuals); dark spot at base of HW small, not reaching cub- ito-anal crossvein...................................................................... amazonica melanica

- Thorax and abdomen red to red-brown; HW basal spot larger................................................... 4

4. Dorsum of pterothorax red to red-brown; HW length 25–27, triangle usually crossed........................ .. castanea

- Dorsum of pterothorax black, sides reddish; HW length about 20–24, triangle usually free......... .. amazonica amazonica