The two species A. alitaeus & pseudomuta have been the source of some confusion in the past.
Undoubtedly there are some intermediates.
The typical forms are never in doubt.

Two criteria helps to differentiate most examples.

A. pseudomuta; HW postdiscal spot 6 narrow & with a margin straight; HW submarginal spots united into a continuous band.
http://www.butterflycircle.com/check...-%20Horace.jpg
http://www.butterflycircle.com/check...1---Horace.jpg
http://1.bp.blogspot.com/-oBtftpJ4gw...yana+(TBC).jpg
http://www.butterflycircle.com/check...e-wee-Kiat.jpg


A. alitaeus : HW postdiscal spot 6 broadly rounded or oval; HW submarginal spots mostly separate lunules.
http://1.bp.blogspot.com/-nEFhYQjWz6...%2BHoraceT.jpg
http://4.bp.blogspot.com/-nl70hCbY-Y...s---KhewSK.jpg
Langkawi.
http://1.bp.blogspot.com/-FK0dW9zrwG...-mirabella.jpg


TL Seow: Cheers.