well, when you see two butterflies in an apparently tumbling flight, wait and look closer and you will see that this is a courtship dance....and without giving too much away, it ends like this below.....
It is a dance of seduction and intoxicating perfume.
The best time for this is around midday, as females and males overlap (very generally speaking) in the flights at this time.
You may follow a zig zagging butterfly, and then if its a male finding a ripe female he will cast tight circles around her.
It can be a challenge to keep them in sight, but occasionally the stars align and you can witness a very elaborate courtship.
The female flies straight, letting off an invisible plume of scent particles: pheromones that she distributes into the air, and that he follows. He will then follow this trail, and also drag his own scent glands near to her, so she is also aware of his smell and would be intent.
She will then either fly off with an "i'm not interested" flutter of the wings, or she will settle, and then follows a much more intimate ritual, which can take place over a few hours. ahhhhh.
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