Charaxes moori or C. athamas?

[DaveChiangMai]

Three photos (unfortunately not the world's best photos) of a Charazes sp from Hala-Bala (extreme s Thailand on the Malaysia border). Of the Charaxes sp occurring in Thailand this can be narrowed-down to either moori or athamas.

C. athamas is common in Thailand, and although variable, usually has two small black dots on the lower front edge of the upper hindwing. This individual shows only one spot. Also on the upperwing athamas usually shows two pale spots near the apex of the upperside of the forewing (one larger, one rather small). This individual appears to have only one spot.

I have no images of C. moori, but other web images seem to show that the chestnut band surrounding the large pale-green centres of both underwings is often concolourous and deeper chestnut. Which is individual does not show.

I would be interested in what is the best way to separate these two in the field.
With thanks

Image 1.
24770

Image 2.
24771

Image 3.
24772

[Psyche]

All three are P. athamas.

The black dot which is on the subcostal basal part of the FW have no value in ID.
THe continental ssp athamas almost always have the tiny FW subapical spot; UnHW redbrown lunules sharply defined.
The Sundanian ssp uraeus lack the tiny subapical spot & the Un HW markings are poorly defined.
Itermediates are frequent so splitting the subspecies is of little value.
ssp athamas. Thailand
http://3.bp.blogspot.com/-py3tc4OOfJg/UoTrLcgmRZI/AAAAAAAAMgU/o_emyPos9Y8/s1600/HFH8692-Polyura-athamas-athamas-(The-Common-Nawab).jpg
Sundanian form usually assigned as ssp uraeus.Malaya.
https://wanderingbutterflyeffect.files.wordpress.com/2010/05/6a0100a801ee89000e0137a57e500d860d.jpg


Polyura moori. The pale green band is broader .It has a distinct indentation directly below the FW subapical spot.
The female has wider band & can be confused with P. jalysus.
http://www.butterflycircle.com/checklist/mugshots/Polyura%20moori%20moori/Malayan%20Nawab%20-%20Cher%20Hern.jpg
http://1.bp.blogspot.com/-7EZLcFK28iA/UrRZuMIs_8I/AAAAAAAANAs/CGEPDyg7ejI/s1600/HFH_0518+Polyura++moori+moori.jpg
https://c8.staticflickr.com/8/7297/28055248831_41e5bb26d7_c.jpg


TL Seow: Cheers.

[DaveChiangMai]

Thank you for the clarification.

[DaveChiangMai]

Ah, so if the black dot(s) which is on the subcostal basal part of the FW has no value in identification, that brings up the headache of identification of C. arja.

The attached two images (Chiang Dao and Doi Inthanon from n Thailand) I have down as C. arja, based mainly on there being a small dot only, plus the pale green band being somewhat broader than the C. athamas (at least in my collection). Hopefully there is a better way of telling them apart, though looking at images on the web it seems no diagnostic way to tell them apart?

Image 1. Chiang Dao
24781

Image 2. Doi Inthanon
24782

[Psyche]

Post 4.
P. arja & athamas can be difficult because of wide variations in the marking. The ID is based largely on colour & width of the band.
P. arja is white & P. athamas is yellow to the naked eyes when they are flying slowly around wet spots.

P. athamas athamas .
Band appearing strongly yellow or yellow green. typically narrow.
Ssp athamas typically have 2 FW basal black dots but may have one.
FW subapical spot narrow or rounded, a line drawn from the outer margin of FW band cut more than half of the spot.
Lunulate spots form a strong curve outwards , above the band.
http://www.learnaboutbutterflies.com/Polyura%20athamas%20001a.jpg
https://wingscales.com/content/record/504-1-1404a.jpg
https://wanderingbutterflyeffect.files.wordpress.com/2013/01/polyura-athamas-athamas-common-nawab.jpg
https://forwildlife.files.wordpress.com/2012/01/110611_5812.jpg
Form with broad band HK (Note: P. arja does not occur in HK.)
http://images1.fotop.net/albums/alanc/butterfly_3/3408_G.jpg
http://yutaka.it-n.jp/cha/60080001.html

P. arja arja.
Bands greenish white (& so appeared white in flight).
Un Band often broad & FW subapical spot typically broad (elongate horizontally)
A line from the outer margin of FW band upwards leaves most of the spot intact.
Lunulate marks not strongly bent out upwards.
FW basal black dots one or if two, the lower one poorly developed.
https://wingscales.com/content/record/1856-1-d2b88.jpg
http://m9.i.pbase.com/g9/25/686825/2/153410229.VEoJlpfx.jpg
http://2.bp.blogspot.com/-YcY30vFVZTM/VQGa0oMBzVI/AAAAAAAAAUU/aq8YhegtkpU/s1600/BBB%2B-%2B0199.jpg
http://www.ifoundbutterflies.org/media_images/CharaxesArja/02CharaxesArja_KrushnameghKunte_ag523.jpg
http://www.dnp.go.th/FOREMIC/NForemic/Caterpillars%20Food/Philips%20pet%20Caterpillar/img27%20march%2055/Nymphalidae/butt/Sub-Charaxinae/%E0%B8%9C%E0%B8%B5%E0%B9%80%E0%B8%AA%E0%B8%B7%E0%B 9%89%E0%B8%AD%E0%B9%80%E0%B8%AB%E0%B8%A5%E0%B8%B7% E0%B8%AD%E0%B8%87%E0%B8%AB%E0%B8%99%E0%B8%B2%E0%B8 %A1%E0%B9%81%E0%B8%96%E0%B8%9A%E0%B8%88%E0%B8%B2%E 0%B8%87/%E0%B8%9C%E0%B8%B5%E0%B9%80%E0%B8%AA%E0%B8%B7%E0%B 9%89%E0%B8%AD%E0%B9%80%E0%B8%AB%E0%B8%A5%E0%B8%B7% E0%B8%AD%E0%B8%87%E0%B8%AB%E0%B8%99%E0%B8%B2%E0%B8 %A1%E0%B9%81%E0%B8%96%E0%B8%9A%E0%B8%88%E0%B8%B2%E 0%B8%8700.JPG
http://yutaka.it-n.jp/cha/60090001.html

1. most likely P. athamas & 2 is definitely P. arja.

TL Seow: Cheers.

[DaveChiangMai]

Many thanks. That colouration difference makes sense.
Still quite a headache to determine/evaluate.