Additional note.

The male of P. sandaka have a large white speculum ( a patch of specialised scales) on the HW.
This is largely hidden at rest.
It is sometimes seen as a white highlight indicating its lower margin.
SANdO.png

http://2.bp.blogspot.com/-c8rXTibfeq...0/DSC_0137.JPG

https://2.bp.blogspot.com/-uNRH3neo0...ascar-Fed3.jpg



TL Seow: Cheers.