What Yellow ?

Shot this Yellow at BSP. Though a bit worn out, I think the markings look different from CGY and the eye looks strange to me also.
Encountered another better specimen but was not able to shoot it.

http://img.photobucket.com/albums/v2...OYellowBSP.jpg

Difficult to tell, Federick. Especially with the condition of the butt. The upperside markings which can be seen through the wings seem to suggest something close to the Common Grass Yellow, but this is one specimen that I'd rather not hazard a guess.

From the HK Book, there appears to be wet and dry season forms of the Grass Yellows. I wonder if this also occurs in Singapore. However, our less-than-distinct wet or dry season makes it a bit difficult to distinguish when we have our wet or dry season. Or perhaps the weather has gone awry these days, and the butts are also evolving along with it.