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Heliaeschna crassa Krüger, 1899

Family: Aeshnidae
Scientific Name: Heliaeschna crassa
Common Name: Nighthawker

Heliaeschna crassa is very rare in Singapore. It inhabit swampy forests and are crepuscular. So far, I have bumped into this species only twice over the span of 5 years of my dragonfly hunting. Once in the forest near Upper Pierce Reservoir, and this one, near Chestnut forest. On both occasions, it’s appearance was caused by my unintentional disturbance while I was walking along the forest trail. My observation of this species is that it tends to be very sensitive to any movements in the surroundings. Once it flies off, it will never come back again. Also, it tends to perch quite low in the dense vegetation.

This is a pretty large species. The eyes of the male are bottle green. The thorax is green and somewhat flatten with greenish transverse flecks and the abdomen of this one is black, probably indicating this is an older male. It has 4-5 crossveins in the median space at the base of the wings.

The top of the frons is black w/o a T-mark. The wings are brownish tinted.

The most unique feature of this species is it’s anal appendages. The male superior appendages is thin and long with a somewhat swollen recurved tip pointing outward. The inferior appendage is very short and slightly recurved.

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This old male was taken in the chestnut forest in July 2016.
IMG_1514.2016.7.31.a
A closer look at it’s appendages. Do you think it’s a H.crassa or H.idae?

This species is definitely one of the rarest species of dragonfly in Singapore. Unfortunately, I only managed to take a couple of shots before this male shoot off and disappeared into the forests.

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