Scientific Name: Idionyx yolanda
Common Name: Shadowdancer
This small and lightly build dragonfly is quite rare and localised in the Central Catchment Nature Reserve of Singapore. They inhabits in small forest streams in the nature reserve. It is listed as critically endangered species in the Singapore Red Data Book. So far, I have only encountered this species a couple of times at the forests at Upper Seletar Reservoir, MacRitchie Reservoir, and Upper Pierce Reservoir.
The eyes are brilliant green. The thorax are short and compact, metallic green, with yellow lateral band. The anal appendages are very distinctive, the inferior being long, trifurcated towards tip. There are yellow patches at the base of the wings.
Males and females are similar in appearance. Due to their small in sizes and greenish-black in colour, it is not easy to spot them in the forests. Occasionally, this species is observed flying erratically, non-stop, over a small area in the forest.