Ooo - I really like this one! Way to experiment with the lighting! Did you use a red gel over a lightbulb, or did you tweak the colour in PS? It looks great, whatever you did. Quite a different feel than I, II, and III; a little more "classic" (whatever that means!)
Composition-wise, I'm usually all about the rule of thirds, but placing the subject in the horizontal middle works well here, as it accents the nice symmetry created by the angles of the wings and the rings of light. My only criticism is that your DOF is too shallow and so the butterfly is soft. Maybe try a larger aperture for your next round.
As for my erroneous assumption that this series has featured different subjects every time, I think you should take a bow for managing to make the same butterfly look so different in every photo! :) (The colour difference between II and III is particularly striking.)
I think my favourites so far in this series are II and IV. Keep it up!