I am still very puzzled by Knight shot by Ying Ling.

Knight is a forest butterfly and it is unlikely that it can fly from the central catchments, Ubin or Telok Blangah Hill Park to AH. The only explanation I can think of is it is 'introduced' into AH through plants brought into AH. I checked with Rosalind and she confirmed that her contractor brought in some Ixora recently.

I am not sure if you guys noticed but the Knight shot by Ying Ling is actually a Malaysian species ! Lebadea martha malayana and not our local species - Lebadea martha parkeri ! The AH contractor could have brought in the Ixora from Johor which explains why it is the Malaysian species.
Anyway, this is just my theory ... and if my theory is correct, this will be the last we see a Knight at AH, unless we start an introduction program