These caterpillars are quite easy to locate compared to other caterpillars if you know the host plant (Australian Mulberry). They appeared in large numbers. (Read my encounters)

Though the caterpillars come in large numbers, very few seem to reach the final pupa stage judging from the pupa that were seen. The light brown empty chrysalis below found on the Australian Mulberry should be from this caterpillar. As for the darker one, it looked like a pupa of this butterfly except that it was found hanging at the edge of a leaf from a Taro plant (Colocasia esculenta).

Online Reference: | Butterfly Circle | Butterflies of Singapore |