Short Banded Sailor | Neptis columella

Neptis columella is a butterfly species native to Southeast Asia and South Asia that belongs to the family Nymphalidae. This species was also known as the short banded sailor or the common sailor.

The underside and upperside of the butterfly's wings are pale black with dashed white bands. Those are the common characteristics that you can know if you find them once.

These are photos of short-banded sailors taken during the mating season. The female is slightly larger than the male.

I can confirm that the one on the right is a male butterfly. You'll notice this when the male's abdomen tip is under the female's abdomen tip; this is when the male is inserting his aedeagus into the female's genitals.