That is a cool looking butterfly. I would have cropped out some more of the tree trunk (about 1 inch) and maybe increased the amount of that nice green follage around it (right and below, not the top).
What a great subject and in a lovely pose. The only problem is that the brightness of the background is a bit overpowering and puts the butterfly in the shade. Nice detail on the wings.
Excellent choice of subjects, interesting, clear sharp focus. Background is slightly overexposed but blurred effect takes away from it as does the subject.
Sweet mother of God where did you find this specimen?
This is one great image you have, I thought I might see some butterflies in this challenge but this one is a cracker. In terms of composition and I would say that the background above and the right of the butterfly detract slightly, largely due to the bright lights. This is however a very minor point due to the crisp focus you have.
Technically I would love to be able to give you some advice, but this picture is way better than any that I have taken so any advice would be meaningless. I guess if I attempted to mention anything, then I would have said that the tree to the left could hopefully have fallen out of focus a tiny bit faster. This is however as much to do with the camera/lens as with the photographer.
Top image -- I hope your final ranking is deserving of the image.