Recently i came across this Great Egg-fly. Apparently this butterfly species has some form of sexual dimorphism between male and female. According to the literature and field guide, the underside of a female is generally brown, with white marginal markings and white discal band (Kirton, 2014). Meanwhile it was reported that, there are currently two sub-species of Great Egg-fly in this region - i) Ssp H.b. bolina and ii) Ssp H.b jacinta. According to Kirton (2014) field guide, the female Ssp Jacinta has white marginal hindwing borders with some bluish discal patches. From the above description, this butterfly should be a female Great Egg-fly from the Ssp Jacinta.
One look at this butterfly you may think that it might resemble a female "Courtesan" (Euripus nyctelus) but with the help of a field guide you will find that a female "Courtesan" has a rounder discal marking.
You can see the bluish discal patches which i believe was where their name has came from.
While photographing the Great Egg-fly, in came this "Common Mormon" (Papilio polytes).
HAVE FUN WITH BUTTERFLIES!