Female Common Blue - Odd behaviour

[Trev Sawyer]

I watched a female Common Blue through my close-up binoculars this afternoon flitting low to the ground and was expecting it to lay an egg. It landed on a plant with very sharp spines on the leaves (Bristly Oxtongue) and seemed to be testing the leaf with its ovipositor. Strange I thought as I didn't think it would use THAT as a foodplant. Instead of producing an egg, the ovipositor seemed to get caught up in the spines and the butterfly then walked around in a circle - still attached. It carried on going round in circles until it had pulled quite a length of its (presumably) reproductive organs out. I tried to get a bit closer and the butterfly tried to take off, but was still stuck. It finished up flapping around under the leaf still attached by its "bits" and I thought for a minute a crab spider had grabbed it from underneath. I turned the leaf over and the butterfly freed itself - there was no spider there. The butterfly immediately flew to a second Bristly Oxtongue flower and repeated the process of dragging the still-exposed tail end around more sharp spines. When it moved on to a third plant and again repeated the process, I had to video what it was doing on my phone. I can add this video if thought useful, but what was it up to? Thinking about it now, I have my own idea, but has anyone else ever seen this and what conclusions did they come to?

[Trev Sawyer]

A still from the video

[David Lazarus]

Hi Trev, very weird behaviour especially given that she did not learn from her narrow escape.

Not unique, as coincidentally I came across this poor female Speckled Wood who had become stuck to a Prickly Sow Thistle leaf.

I saw this and thought, what is going on here?

Speckled Wood female
One Tree Hill 13/08/2024

I was like, she cannot possibly be laying an egg on a Sow Thistle leaf high up above the ground. I thought I would snap away just in case:

Speckled Wood female
One Tree Hill 13/08/2024

I noticed she was stuck by her abdomen and had to rescue her by tearing the leaf and gently trying to peal her off - she gleefully flew off but left some fluid behind so she is damaged.

I am hoping, in her case, that she did not try it again.