Thursday, October 20, 2016

187. Aciagrion sp.

Number: 187  
Family: Coenagrionidae 
Genus: Aciagrion   
Species: Aciagrion sp. (possibly A. occidentale)
Common name(s): N/A  
Synonyms: N/A    
Habitat: Forested pond   
Province(s) sighted: Phu Khieo Wildlife Sanctuary (Chaiyaphum)  
Sightings (by me): 3-4 males spotted at one natural pond 
In flight (that I have seen): October    
Species easily confused with: All Aciagrion species

Tiny, blue and all look the same! Talk to any dragonfly lover about Aciagrion and they instantly wince. It is an incredibly difficult and confusing genus that needs to be resolved - though anyone who dares to do it is a brave individual indeed. There are several known species in Thailand, though one or two of them could have been misidentified (possibly even by the original authors). That said, it seems that there are possibly several more out there that are yet to be described. One of which, I may have spotted last week. It is an Aciagrion species that seems to fall between A. hisopa and A. borneense with a sprinkling of A. pallidum thrown in for good measure. Superficially, it looks like A. borneense. However, the striking difference is the solid blue patch on the abdomen (save a tiny "v" nick) and the appendages are white. The colouration of the rest of the male seems to match that of A. borneense. If it was the only specimen, then I would possibly put it down to being a slightly different population of A. borneense. However, through Dragonflies of Thailand (on Facebook), it appears that this species (with exacting markings) has been spotted at several locations throughout Thailand, though is scarce or overlooked. Also, looking back through my records (old photos) it appears that I did spot a young male (very pale but with a solid patch) at Nam Nao a couple of winters ago. Unfortunately, I was unable to catch one (I saw 3-4 males at one location) as I had forgotten my net. I will return to try and collect a specimen. For now, however, it can only be known at Aciagrion species - until someone far braver than me takes up the horrible and extremely confusing Aciagrion gauntlet and goes back to the drawing board with this genus. Probably not in my lifetime though haha.

The 'new' Aciagrion species (to add even more confusion to the boiling Aciagrion pot):

For comparison, here are photos similar species (where - though subtle - you can make out differences):

1. This one taken at Nam Nao a few years back I first though was A. borneense, but you can just make out the markings (which are similar to that of the specimen above), though this could even be A. occidenale aaarrrggghh!!!)

2. A pallidum, a common winter species (here, this male has whitish appendages...
... though many have a more reddish/orangy colour (often more than this)...
...or an even more confusing blue colour (though this could be another species!!!)
3. A. borneense - here you can clearly see the typical markings which make ID possible - very different than the new species. Easily the most common species.
4. A. hisopa - similar to the 'new' species but completely blue (no green) and the ocelli (eye spots) are large. Also, from memory, it is slightly larger too.
5. Just for good measure, here is A. approximans, another fairly common uplands species to add to the mix (though fairly easy to separate with its purplish hues).

So, there you have it. Aciagrion is as clear as mud! Over to the experts.

Monday, October 17, 2016

Back to Baking Heat at Phu Khieo WS

Location: Phu Khieo Wildlife Sanctuary, Chaiyaphum
Date: Thursday, 13th October, 2016
Habitat: Mid- to upland forested ponds

Well, I returned to Phu Khieo in order to find another elusive species (most of which still are and the search goes on). I knew it was Amphithemis curvistyla time. The species has apparently been recorded there and is only out for around 6 weeks and it was right slap bang in the middle of their flight time. Not surprisingly, though, I didn't get to see any. I just wonder if it is just a little too early this year due to the messed up weather and the fact that everywhere was still swamped. I will return in a week or two. Other than the usual suspects still showing in baking heat, everything is starting to quieten down now, as expected. However, even now, there was a surprise or two to be had. I managed to spot Amphiallagma parvum for the first time and they were in decent numbers, especially at the flood pond (near the marshy area where A. hisopa (or very similar) was abundant last November). The only other thing of note was a rather peculiar Aciagrion species. Could be A. borneense, but I don't think so. To add to the confusion, I saw a number of A. borneense at a slightly lower altitude (see copula below). I am at a loss as to what it is. I saw 3-4 males the one natural, uplands pond (where I once stood on a massive python, which didn't even react). Sadly, I had forgotten my net and was unable to capture any. I will return very soon and try again. 

My best photos of the day:

The conundrum of the day: Aciagrion.... what?

Aciagrion borneense, copula (at slightly lower altitude). Here you can just make out the wide black markings on the abdomen - which makes it easier to separate, whereas the specimen above is almost solid blue.
Welcome to Phu Khieo... my first sighting of the tiny, but stunning Amphiallagma parvum, male...
 ... and the female
The usual equally beautiful Ceriagrion azureum (though in much smaller numbers now)
Aciagrion pallidum, male - with white appendages (some have an orangy colour).
Orthetrum pruinosum neglectum, male. Very common right now.
 Diplacodes nebulosa, copula. These were everywhere - but my first decent shot of a copula.
The super-common Ischnura senegalensis, copula. Still nice, though
 Lestes concinnus, replaced most of the other Lestes species now and was incredibly abundant.
Gynacantha subinterrupta, teneral male - usually abundant everywhere, but rather scarce here.
Ischnura aurora aurora, male - a few made an appearance
Lestes elatus, female. Seemingly more abundant later in the year.
Very scarce here, for some reason... Orthetrum luzonicum, teneral female

Ooops ... poor damsels.

Can you guess the species?
 Orolestes octomaculata, teneral female
... and this one?
 Cratilla lineata calverti, teneral male

What, no frog?!?
Not all dragons fly. This stunning, but lazy Monitor Lizard was plonked right in the middle of the road.
 No idea what species, but there were several along the road early in the morning. This one was a decent size.