Last Updated on Monday, 12 June, 2023 09:37:49 AM

INDEX  >  Dragonflies of Borneo  >  Family Libellulidae  >  Brachydiplax chalybea

Brachydiplax chalybea
蓝额疏脉蜻/橙斑蜻蜓
Blue Dasher

Found in Asia: China, Indonesia, India, Cambodia, Myanmar, Malaysia, Philippines, Peninsular Malaysia, Thailand, Viet Nam
 

Brachydiplax chalybea is a moderate sized dragonfly commonly found in unshaded body of water, such as ponds, stagnant or slow flowing streams and drains. The males are a powder-blue in color with hind wings that are tinted brown at the base and are often seen perched by the water and every now and then flying out to challenge any intruder that wanders into their small territory.

 

Egg mass of a female dragonfly Brachydiplax chalybea

♀30mm
2017-05-31 SG. TAWAU RIVER

 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.
Males pale to mid powder blue. Females have shades of brown.

Like most Libellulids they tend to perch on sticks, reeds or stones near water, flying out to catch insects then returning to their perch

 

More on EGGS OF DRAGONFLIES


 

Eyes of a male Brachydiplax chalybea

Though a widespread species, the female of Brachydiplax chalybea is seldom seen. The brownish female only appears to mate and oviposite in the afternoon after which back to the hiding bush again. It is a common dragonfly 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.

The brownish female is completely different in color to the powder blue of the male. I would not be sure this is a Brachydiplax chalybea if not I spotted them in a pair earlier ( The blue male being immediately recognize). The mating time is only few seconds after which the female oviposit alone.

A sticky egg mass in segment 9 surrounded by jelly . Brachydiplax chalybea’s egg is pale blue in color. Eggs of most other dragonfly species are yellowish. Female dragonflies produce a sticky substance surrounds the eggs. The sticky substance keeps the eggs together and holds the eggs to an anchor to the plants in the water.

Wing venation of a female. Both wings are clear with tinted brown at the base. Brachydiplax chalybea is powder blue of moderate size. The hindwing is clearly tinted brownish-yellow at the base.

CHART OF DRAGONFLIES OF BORNEO

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Most of the common dragonflies in Sabah are red coloured, especially from the family Libellulidae.  Some red pecies are even confused as same species, for example the three species of Genus Neurothemis.

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Dragonflies and damselflies have large compound eyes that can see in all directions. When the compound eye is magnified several hundred times, each individual facet (ommatidium) is shown to be hexagonal in shape.

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of Female Dragonflies and Damselflies

Female dragonflies have either one of the two method of depositing eggs from the abdomen:
1- using Ovipositor Structure
2- using Vulvar Lamina

Male do not have an ovipositor. Instead male dragonfly and damselfly have appendages.

Damselflies of Borneo