Please help with the ID of this butterfly

[Samuel T]

Dr Seow please help with the ID of this butt. Thanks.

Samuel

[Psyche]

I supposed that this is not taken in Singapore, otherwise it would be something new.

This is either Prosotas pia or bhutea.
The two are very difficult to separate in fieldshots.

P. bhutea .FW both outer & innermost bands not extending down in to space 1b ,ie the lowest space.
https://www.neutron.phys.ethz.ch/Lepidoptera/Old_Specimens/Lycaenidae/AZ11-0202V.jpg

Prosotas pia & nora. Both bands extending into space 1b.
This is P. nora from Sulawesi.
https://www.neutron.phys.ethz.ch/Lepidoptera/Old_Specimens/Lycaenidae/AZ11-0349V.jpg

At rest it is impossible to see this unless the FW is raised high enough.
P. bhutea ,India, all with the FW raised; note FW innermost band not extend downwards.
http://www.ifoundbutterflies.org/sp/688/Prosotas-bhutea
Thailand misIDed as P. pia.
https://farm5.staticflickr.com/4503/37566391576_4a293d2c30_b.jpg

P. pia FW with innermost band extending downwards; HW submarginal spots faded, less dark than marginal spots.
http://www.ifoundbutterflies.org/media_images/ProsotasPia/01ProsotasPia_KrushnameghKunte_ai937.jpg

P. nora :FW innermost band extend downwards. HW marginal & submarginal spots equally dark.
http://www.butterflycircle.com/checklist/mugshots/Prosotas%20nora%20superdates/Common%20Line%20Blue%20-%202%20-%20Simon%20Sng.jpg

In P. pia the marginal & submarginal spots are of varying intensity to one another making it very similar to P. bhutea.

Because the marginal & submarginals are both very faded ,I think it is P. bhutea.
If in Singapore it is more likely to be P. pia.

Both are commoner in the hills.

TL Seow: Cheers.

[Samuel T]

Thanks Dr Seow. It’s indeed not captured in Singapore. It was taken in Taiwan recently. Thanks for the detailed explanation. Much appreciated.

Cheers
Samuel

[Psyche]

There is only one species of Prosotas in Taiwan, P. nora formosana.
https://farm4.staticflickr.com/3851/15178164112_9871daf31e_b.jpg
https://c2.staticflickr.com/8/7770/18077253830_29e7a9dd4a_c.jpg
https://commons.wikimedia.org/wiki/File:Prosotas_nora_formosana_ventral_view_20140607 .jpg

This seems to be an extreme form where the marginal & submarginal spots are mostly faded out.Very unusual.

TL Seow: Cheers.