Part 3 is the body of the butterfly.
The body starts at the ring on top of the antenna:
It is worked CTM with 2 shuttles filled with a yellow dmc size 80 thread. After the little ring, the antenna is a zig zag chain, that is 4 first half ds followed by 4 second half ds, repeated for 8 times. That is called also "victorian set", as I found it here: http://www.georgiaseitz.com/setstitch.html
Then there's a face inward picot, there's various methods to do it, I've just mine that I showed in a drawing in Flickr: https://flic.kr/p/agHxVU
Wings are joined along the body. It may be finished at this point, a pretty butterfly side viewed on a flower, so we need the pattern for a flower. Priscilla's pansy?
The pointed bottom of the body has two stitches made with the second shuttle, an effect that Jon called Pointed chain:
That is how I do it:
For the last antenna I have a trick. In the first I made, that actually came out very floppy, the tension can't be perfectly regulated at the end. So I thought to fold the core thread as in a SSSC, tat the zig zag chain and the last ring (with 2nd shuttle). Blocked the core thread loop with the ball thread, at the end I had just to pull the first shuttle to adjust the antenna.
I hope to see your butterflies soon! Happy tatting!