You are quite right, it is Pithauria straminiepennis.
Because it was thougt to resembles Onryza, I was thinking small.
Here are the two for comparison. Note the FW chequered cilia of H. burmana.
http://www.ifoundbutterflies.org/med...ekar_ag187.jpg
http://d.mp-farm.com/b/500x450.water...00/3305723.jpg
TL Seow : Cheers