It has been hard to find butterflies this year for some reason, so you are lucky! To critique it, I think it is a little soft and suspect you have cropped in tightly, thus loosing some definition. I wonder too if you have over-sharpened it by the look of the background? What camera are you using and is this a jPeg or RAW format, and if the latter what post processing software are you using? I hope you don't mind my critique?
@marshwader It was great to see this butterfly, like you I've hardly seen any this year. I had my Nikon DSLR with 35mm lens, I was in a garden centre and couldn't get any closer to the butterfly without trampling on the plants, so this is cropped. It's RAW and processed in Lightroom, a little sharpening, slight contrast and highlights/shadows adjustment but not much else. I chose this one because I liked the curl of its proboscis! I wish I could find some more butterflies to practise on! Thanks for your critique, I appreciate it.