[S] Tortoise beetle

This seems to be a freshly emerged (teneral) individual, which hasn't reached it's "normal" colouration yet. Cassida circumdata seems to be a likely candidate, and also one of the most common tortoise beetles in SE-Asia. There are many other Cassida species in Indonesia, also some that look quite similar to C. circumdata, so I can't be sure about the species. Deloyala is an American genus that doesn't occur in Indonesia.