I like the crop posted by sniperjhs. Your original image had a lot of unnecessary material in it. The KISS principle is of importance when posting images of any subject - (Keep It Simple and Straightforward) - if it doesn't contribute to the image then it is probably unnecessary. The other problem you have is that you are shooting a darker subject against a lighter background, so, depending on your meter settings you will always under expose the subject. The suggestion is that in cases such as this you would probably want to use an exposure compensation of 1/2 to 1 stop to provide better exposure for the details in the butterfly. This may over expose the background a bit, but it is better to have a properly exposed subject. I don't usually worry about the background as it is, or should be, mostly out of focus.
WesternGuy