Dear Seow sir,
Things becomes more interesting for us right now...as my dear friend Ngangom Aomoa and me possibly photographed more Pantoporia sandaka than Pantoporia hordonia in Meghalaya...
Here some more images to share...
I just want to confirm whether they are Pantoporia sandaka??
1. female dsf Pantoporia hordonia.
The female of both species have the foot of the FW postdiscal band, that runs along the FW lower margin short.
The females of the two species can be very similar & difficult to separate.
Note the grey line is constricted but large & separates the orange line & band well.
Compare the female sandaka below in which the grey line within the black is almost obsolete. http://www.indianwildlifephotographe...a_Hordonia.jpg
2. P. sandaka male normal form. Note grey line reduced to a few tiny streaks.
3. P. sandaka male dsf. Wider orange markings ; extra line along the margin.
4. P. hordonia male dsf. Extra marginal orange; Note grey line wide . The foot is long but in India the foot is variable.
In Malaya the foot is larger & longer in P. sandaka than in hordonia,but this difference is not applicable in India.
If upper margin of the cell-bar in a male have two strong notches it is likely to be P. hordonia.
P. sandaka may sometimes have 2 notches but usually weakly so. http://www.ifoundbutterflies.org/med...unte_aa859.jpg