In any collection in the past there is always several odd specimens which do not fit properly.
1. The underside & upperside suggest a cross between a male berenice & a female calauria.
Only a male berenice can pass on the genes for the white ribbon scales giving it its frosted pale blue colour.
FW submarginal spots 4 & 5 are triangular esp females in calauria. HW only submarginal spots 4 & 5 have points.
FW submarginal spots 4 & 5 are chevron, more 'V' shaped in berenice . HW submarginal spot 3 or all the spots may be pointed.
The Biodiversity of Singapore website's N. calauria is almost certainly a male N. berenice.
Someone sent me this Nacaduba for ID and I would like to hear your opinion. I assume its a female since it seems like its ovipositing and there are many eggs. The FW post-discal band is dislocated like N. berenice, but the very large and rounded submarginal spots are are more typical of N. kurava.
Here are a few Rapala shot by Jess at Sungei Buloh Wetland Reserve. The post discal bands seem to be a lot darker and more prominent than usual and the orange crown seems to be more of a thin ring, also seen at a mangrove, could it be Rapala cowani?