Tad Xai Waterfall in Laos is a wonderful place to find butterflies. On the day I was there, a professor from the university in Vientiane had baited around the falls. He had two Japanese Lepidopterists with him. They were all intent on documenting the butterflies of Laos. The professor told me that there are 900+ species of butterflies in Laos. He was trying to document all of the species before some of them disappeared due to all the deforestation taking place. Much of the native forest is being replaced with crops including rubber trees.