So far I met four species of these group. The first one is obviously the Indo-Australian species: Leptotes plinius or the Zebra Blue. This was in India, however it has a very wide distribution. I have interacted with this butterfly numerous times.
Second species of the group that I have met is Leptotes cassius or the Cassius Blue. This species is distributed in Florida and Texas all the way down to South America. This butterfly can be seen around Plumbago or few other Fabaceae plants.
The third species is Leptotes pirithous or the Lang's Short-tailed Blue, who I met in Haifa, Israel. When I saw both these species in Florida and Israel, I thought, "Oh the Indian species is here too," but then I found out that they are all actually different species which look very similar.
The fourth one I met recently in California. This is the Marine Blue (Leptotes marina) which is distributed more on western USA and Mexico.