On this note, i would like to inquire how do i differentiate Caltoris philippina and Polytremis lubricans?

Im still relatively new at IDing skippers and these two gives me a very hard time. Both shares similar colouration and course scaling,and i feel that from pictures the spots seem to appear in the wings of both species as well

Would like to inquire how can i learn to differentiate both

Regards
Zick