Julie, when you use a macro lens of 105mm, is very tricky with DOF.It is very, very narrow.You just have a few seconds when the butterfly stays with his wings wide open and really in focal plane! You are really close to the butterfly (about 0,5 meters) and he is not very "happy" about it...:)
All the butterflies that I have photographed, are in the wild, not in some butterflies farm, so you have wind, sun, and many other insects which can interfere with your subject.Also, the BG is very close to the subject, so there isn't much to do about it...All my photos with butterflies were taken hand-held...