Thursday, June 9, 2011

125. Pseudagrion australasiae Selys, 1876

Number: 125
Family: Coenagrionidae
Genus: Pseudagrion
Species: Pseudagrion australasiae
Common name(s): Blue-headed Sprite, Look-alike Sprite
Thai name(s): แมลงปอเข็มบ่อออสเตรเลีย, แมลงปอเข็มบ่อฟ้าใหญ่
Habitat: Exposed ponds and lakes (uplands & lowlands)
Province(s) sighted: Khon Kaen environs; Nam Nao NP/environs (Petchabun);  Widespread (Chiang Mai); Khao Yai NP (Nakhorn Ratchasima); Khao Kitchakut NP (Chantaburi).
Sightings (by me): Fairly common
In flight (that I have seen): April-December
Species easily confused with: Pseudagrion microcephalum; Cercion malayanum;

One species that I'm sure I have seen a number of times is Pseudagrion australasiae. However, unless you are very, very close to it, it is hard to tell the difference between P. australasiae and P. microcephalum. Having studied photos for a long time, one difference I have noticed (I think) is that P. microcephalum is a brighter, more vivid blue. Whereas P. australasiae is a slightly more muted blue. Also, P. australasiae is slightly bigger but has shorter caudal appendages compared to that of P. microcephalum

The male
As mentioned above, the male is very similar to the male of P. microcephalum. If you see two together, it is easier to compare as P. australasiae is duller in colouration and is also larger. Also, P. microcephalum is far more common in Khon Kaen and the surrounding areas. 


 









P. australasiae is slightly larger than P. microcephalum (a good way of IDing if seen together)



The superior (top) appendages are shorter than those of P. microcephalum



dorsal view ...





A youngish male
This one hasn't quite developed that shimmering blue colour.


The 'adult' female...
The female is very similar to other females in the genus. However, for me, I was lucky recently. At at large, shallow lake I saw recently at Khao Yai, Nakhon Ratchasima province, I spotted many males and females, including the female at all stages. P. microcephalum wasn't present, making identification much easier.

Here is a very old female.


The adult female is blue in colour.


The 'mid-stage' female...
Here, we have a mid-stage female, which is just showing signs of blue on the thorax.


The 'young' female...
This is a young female, which is brown in colour. There were many of these early in the morning. However, once the sun came up, they all vanished into the bushes and trees.

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