Genus Brachydiplax
Brachydiplax chalybea is powder blue of moderate size of 26-28 mm and rather heavy build. The hindwing is clearly tinted brownish-yellow at the base. It is one of the most frequently encountered species of Anisoptera in lowland Borneo, found on virtually any open body of standing or slowly flowing water including artificial drains and dams. It is commonly encountered at the landward margins of mangroves. Typically males establish small territories of a few square metres, and contests are frequent and protracted especially in the latter part of the morning. Mating and oviposition occur in the afternoon.
Brachydiplax farinosa is a scarcer species known from forested swamps in south and east Borneo and Brunei. It is a good deal smaller (S hw, 22-23 mm) than B. chalybea and the wing bases are clear, rather than brownish-yellow.