This impressive creature was on my wish list before we set off for Singapore. Our first two excursions failed to find one so I was delighted to snag an albeit rather distant one on the Siem Reap river in Cambodia. A second trip the the Singapore Botanic Garden did prove successful; we found a couple of examples and furthermore they cooperated by posing nicely. No females, though.
[I. rapax is very similar and I have a comparison chart showing distinguishing features from I. decoratus.]