227: Orchithemis pruinans (Selys, 1878)

      Number: 227 / Family: Libellulidae / Genus: Orchithemis

Species: Orchithemis pruinans  / Blue Sentinal

Province(s) sighted: Narathiwat

Habitat: Forest Peat Swamp

In flight: August / Sightings (by me): Rare

Species easily confused with: Orchithemis pulcherrima

Another species I expected to see at Sirindhorn Peat Swamp was Orchithemis pruinans, and it didn't disappoint... eventually! For the first part of the morning, it didn't show but then one eventually turned up and later in the day, a few more appeared, through no females. In all, there were around five  or six males spotted. Definitely not a common species, as it is only known form this location in Thailand as far as I am aware. Also known as the Blue Sentinal, it is very similar to the black form of its cousin, O. pulcherrima, though this species has a much slimmer abdomen. 

The Male

From a distance, it looks uniform black with a single white band, but when you photograph it and look closely, it has several colours and one being the pruinescence on its thorax, possibly where 'Blue' in the common name comes from. He is a rather stunning chap and not too difficult to approach once the day heats up.

208: Orchithemis pulcherrima Brauer, 1878

Number: 208 / Family: Libellulidae / Genus: Orchithemis

Species: Orchithemis pulcherrima / Variable Sentinel

Habitat: Forested Lowlands Streams

Province(s) sighted: Chantaburi, Narathiwat, Ubon Ratchatani

Sightings (by me): Uncommon

In flight (that I know of): July-August

Easily confused with: Orchithemis pruinans

A species that had the Facebook dragon guys scratching their collective heads was a rather plain looking female. It looked a little like a Lyriothemis species until it suddenly dawned on someone... it was Orchithemis  pulcherrima -- a new species for most of our records! Amazingly, one or two members even got a fleeting glimpse of a red male high up in the tree canopy, though I missed it. 

It likes to perch on twigs at the edge of the forest. However, with the weather being so poor, the others weren't showing. Since then, I have spotted a solitary male in Ubon Ratchatani province, and several males and females in Narathiwat province, where it was a little more common.

The 'Red' Male

I think this is the standard form, though correct me if I am wrong. This was a solitary male I saw under heavy tree cover in the gloom at Phu Chong Na Yoi National Park in Ubon Ratchatani in 2022.

The 'Orange" Male

This male will likely turn red eventually and was actually quite skittish.

The 'Black' Male

This is very similar to O. pruinans but has a much broader abdomen. This specimen hovered for a long time in the hope that a female close by would fly. 

The 'Purple' Female

I think that this is one of a few forms of female too... this one has a more purplish colour to it. 

The 'Yellow' Female

I think this is a young female and may go darker eventually.

The "Old' Female

This, is think, is the normal female, but old just old (you can see how the colour on the thorax is different than the 'Purple' female above.