The other day I followed a pair of Common Blues hoping they would mate. The female led the male a merry dance. Whenever she settled the male would join her and examine her rear end, then she would be off again. I shot a lot of photos as my eyesight is poor. It is clear that the tip of her abdomen is raised vertically. No mating took place.
This morning Dave Redhead, our Pembs. Butterfly recorder, came past. He told me that this female was already impregnated and was just wanting to lay her eggs and that the raised tip of her abdomen is a rejection sign. I hope the male eventually left her in peace and found a more suitable and willing partner.
I’ve added a photo of a successful mating. Another couple.