You need to keep on shooting these. The grasses in front of the butterflies are a distraction. Next time (and I know it isn't easy, not much time), see if you can walk around to another angle where nothing blocks the view. Sharpness in the bodies and wings of the top butterfly is WONDERFUL.
Nice photo. Agree with etfon. Cant tell you how many times otherwise great photos have suffered from having something that distracts the eye and ihave to keep going back and trying to catch the moment. the good thing about photos like this is that next time you know what you are looking for.