Focus Stacking and a Moth

We found this really neat moth on our porch several days ago. It had already departed. It was in immaculate condition, and seemed the perfect opportunity for some focus stacking effort. As usual I used CombineZM for the processing, and my Nikon D40 with el cheapo Phoenix 100mm f/3.4 macro lens. Combination of about 20 photos, if I remember accurately. Anyway, for those of you who use CombineZM, the produced the following was the weighted average method.

I will award 5 points to anyone who can identify the stacking artifacts in this picture.