Female chasing a male

[Phil Bowler]

9.10.23 An unusual occurrence witnessed in our butterfly garden: on this gorgeous warm and sunny autumn day a female Brimstone being observed feeding from French marigolds, rose up at a passing male and chased him around the garden, in exactly the same way as the males do in the spring.After a few minutes they both flew into the neighbouring field, the male still being pursued by the female! Why? Especially in the autumn? I’m confused – maybe she was! Any suggestions anyone?