This is a moderately large and rare dragonfly which inhibits slow flowing streams near swampy forest in the Central Nature Reserve of Singapore. This species can be seen flying swiftly along forest trails or hanging from high branches at MacRitchie Reservoir.
This species has brilliant bluish-green eyes. There is a conspicuous white saddle cutting across the dorsum of the thorax of both sexes. Both sexes has dark patches at the base of the wings.
From my observance, this species tend to be more active in the late morning to early afternoon. You’ll need to have good sharp eyes to locate them as they tend to hang motionlessly on twigs or high branches.
Scientific Name: Brachydiplax chalybea
Common Name: Blue Dasher
Brachydilpax Chalybea is a relatively small dragonfly from the family of Libellulidae, a species which is very common and wide spread in Singapore. It usually inhibits ponds, streams, and some disturbed areas outside the nature reserves. Female is less common and may appear only when mating.
The male of this dragonfly has a powdery blue thorax with light to brown patches. The abdomen is also powdery blue with the last three segments dark in colour. It also has a dark yellowish tint at the base of it’s wings. Female is generally similar in size but has more orangey body and dark markings along the dorsum of the abdomen. Unlike male, female has clear wing base.
Males are often territorial and are very active in the morning and early afternoon. This species is very similar to Aethriamanta gracilis, but the latter species is smaller in size and has a wider wing venation. It is also quite similar to Raphismia bispina, which is rare in Singapore and inhabits only at mangrove swamps.
Female of this species is more attractive, and less common.