An interesting, aberrant Arhopala

[atronox]

Found this very timid Arhopala today which never allowed an easy shot. It was quite small, the size of A. abseus and seems aberrant; the forewing post-discal band is completely missing.

However, the character that stood out to me is the dislocated hindwing post-discal band at vein 2, which means this is quite likely A. avathina avathina.

Thoughts?

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[Psyche]

Agreed it is very likely A. avathina.

Intrestingly Fleming also list A. kurzi in Singapore.
This also have the HW postdiscal band widely dislocated at vein 2.
It would seem A. kurzi have a tendency for the 'V' spot to be broken into two.
http://3.bp.blogspot.com/-_vsUP_6bf3k/U31CP5qlWnI/AAAAAAAAOk8/QQFrsRPQXzI/s1600/DSC_0683.JPG
This is also seen in Yutaka's specimens (Zoom to view)
http://yutaka.it-n.jp/lyc4/81926001.html

TL Seow: Cheers.

[atronox]

Thanks, Dr Seow. I originally thought it was an aberrant muta/moorei but decided not because of the spot arrangement.

I attach another shot from a different angle, this time with vein 2 obscured. I increased the contrast so that the spots are more visible. Would you still consider this avathina?
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*It always landed in the most awkward positions. I had to literally climb a liana to get this shot!:bsmile:)

[Banded Yeoman]

Here's the holotype for A
Arhopala avathina from Singapore.

https://m.singapore.biodiversity.online/species/A-Arth-Hexa-Lepidoptera-000436

I would still be hesitant to place Aaron's Arhopala as this species are it is just a little to worn to discern the main diagnostic features..

[atronox]

https://m.singapore.biodiversity.online/species/A-Arth-Hexa-Lepidoptera-000436


This one strangely has a slightly different spot arrangement. This is getting interesting

[Psyche]

I thought the Singapore Biodiversity site have only the upperside image in my search.

With a proper underside this doesn't match.

C&P4 states in A. avathina the postdiscal band is completely dislocated at vein 2, not dislocated widely as here.
The green metalmark is large & elongate & also does not match.

The closest it come to is A. hypomuta.
https://en.wikipedia.org/wiki/Arhopala_hypomuta#/media/File:ArhopalaHypomutaHypomutaFUpUnAC1.jpg


TL Seow: Cheers.

[atronox]

Thanks everyone for all the input. I shall just leave this as "cf. muta" since its exact ID will probably never be determined.

Dr Seow, the one in the wiki link seems misIDed; it should be muta

[Psyche]

Thanks everyone for all the input. I shall just leave this as "cf. muta" since its exact ID will probably never be determined.

Dr Seow, the one in the wiki link seems misIDed; it should be muta

You are right. The upperside is closest to A. muta female.
I think this have been discussed before.

A. hypomuta ;FW postdiscal spot 4 dislocated & shifted out from spots 5 & 6.
HW with spot at base of space 6 (not always present).
http://4.bp.blogspot.com/-y9dabOUmO0o/U0ssd5CPikI/AAAAAAAAN3w/XFc_t-AHZz8/s1600/DSC_0188.JPG
http://nlliew66butterflies.blogspot.com/2014/04/arhopala-hypomuta-hypomuta-hewitson.html

Note the underside HW of A. hypomuta is a fairly good match.
The dislocation at vein 2 is wide; green metalmark long (but broken ).


TL Seow :Cheers.

[Banded Yeoman]

I chanced upon this shot by CJ in Panti forest (2013) and I'm certain that this is Arhopala avathina.
http://www.butterflycircle.com/showthread.php?14223-CJ-Party-in-Panti-2013&highlight=

The original caption:


Arhopala ___? (Subject was really tiny)
https://live.staticflickr.com/65535/48356165457_2c014c5f1a_o.jpg

It meets all the criteria clearly.

- The size description is enough to narrow it down to a muta-subgroup species.
- HW post-discal band completely dislocated at vein 2. It can now only be muta, moorei, metamuta or avathina.
- Sub-marginal spots dark and unsually well defined, even in this worn individual.
- FW post-discal spots 3 and 2 more or less in line, spot 2 slightly shifted inwards compared to 3; post-discal band shape corresponding with holotype.

The green tornal metalmark is broad but this marking is often variable.

[Psyche]

post 9.

It is not Arhopala avanthina but something equally interesting.


The diagnostic ID for A. avanthina is that the FW basal cellspot is absent.
In the image all three cellspots are present. ie. one at cellend, one at mid cell & the 3rd basal (actual position is sub-basal).

Arhopala kurzi have 1. all three cellspots present, 2. HW postdiscal band widely dislocated at vein 2, & 3. FW postdiscal spot 3 (ie. in space 3) elongate towards base (variable).
All three criteria are met here.
https://singapore.biodiversity.online/species/A-Arth-Hexa-Lepidoptera-000440


TL Seow: Cheers.

[atronox]

The diagnostic ID for A. avanthina is that the FW basal cellspot is absent.
In the image all three cellspots are present. ie. one at cellend, one at mid cell & the 3rd basal (actual position is sub-basal).

Could this be variable? D'abrera figures a specimen with the basal cell spot

[Psyche]

Could this be variable? D'abrera figures a specimen with the basal cell spot

The key in C&P4 is quite specific in this differentiation.

Still , this should be easy to test.

The upperside FW border is a thread in the male A. kurzi.
https://singapore.biodiversity.online/species/A-Arth-Hexa-Lepidoptera-000440

The upperside border in A. avathina is much wider , 1mm.
https://m.singapore.biodiversity.online/species/A-Arth-Hexa-Lepidoptera-000436


TL Seow: Cheers.

[Banded Yeoman]

Dr Seow, Aaron, thanks for your views on this one. I continue to learn.

The feature of fw basal spot missing is unhelpful in my limited opinion. Even the holotype of A. avathina clearly shows fw sub-basal spots - and if the characteristic truly was regarding the basal spot, which is sometimes discernable in very pristine examples of muta, kurzi etc, it is often too faint to use as a distinguishing feature.

I would be hesitant to id this one as A. kurzi.

It now becomes clear that even in A. kurzi, the sub-marginal spots are rather dark and defined. From all valid A. kurzi specimens that I've seen, however, the forewing band is distinctively broken at each vein for spots 4, 5 and 6. These are specimens with upperside confirmation.

A. avathina, in the holotype from Singapore, displays fw post-discal spots very well aligned. This is also seen in CJ's shot (post 9).

Dr Seow, your point of separating these 2 species by upperside is definitely the most solid method. They prove to be very similar on the underside.

[Psyche]

Dr Seow, Aaron, thanks for your views on this one. I continue to learn.

The feature of fw basal spot missing is unhelpful in my limited opinion. Even the holotype of A. avathina clearly shows fw sub-basal spots - and if the characteristic truly was regarding the basal spot, which is sometimes discernable in very pristine examples of muta, kurzi etc, it is often too faint to use as a distinguishing feature.

I would be hesitant to id this one as A. kurzi.

It now becomes clear that even in A. kurzi, the sub-marginal spots are rather dark and defined. From all valid A. kurzi specimens that I've seen, however, the forewing band is distinctively broken at each vein for spots 4, 5 and 6. These are specimens with upperside confirmation.

A. avathina, in the holotype from Singapore, displays fw post-discal spots very well aligned. This is also seen in CJ's shot (post 9).

Dr Seow, your point of separating these 2 species by upperside is definitely the most solid method. They prove to be very similar on the underside.


If you look at the heading in the link, it says Arhopala avathina avathina Corbet 1941.
Corbet was the author of A. avathina & he wrote the key first based on his holotype specimen.
The image is too blur & vague to say there is a FW basal spot.
https://m.singapore.biodiversity.online/species/A-Arth-Hexa-Lepidoptera-000436
My point is if there is a basal spot in this holotype then Corbet would not have written otherwise.

The 2nd point to note is that FW postdiscal spot in space 3 is when fully developed extend towards the base ie elongate horizontally in A. kurzi.

3rdly A kurzi was recorded in Singapore, and as a species is not rare as in A. avathina.




TL Seow: Cheers.

PS. Having a close scrutiny of the image od A. avathina, there does seem to be a basal spot on the left side FW.
Unfortunate there also is a label of Hewitson's A. hypomuta. This raise a question of whether there is a mixup with the specimen.