Female Common Blue - Odd behaviour
- Trev Sawyer
- Stock Contributor
- Posts: 855
- Joined: Sun May 07, 2006 8:37 am
- Location: Cambridgeshire
Female Common Blue - Odd behaviour
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?
Last edited by Trev Sawyer on Sun Aug 18, 2024 10:09 am, edited 1 time in total.
- Trev Sawyer
- Stock Contributor
- Posts: 855
- Joined: Sun May 07, 2006 8:37 am
- Location: Cambridgeshire
Re: Female Common Blue - Odd behaviour
A still from the video
- David Lazarus
- Posts: 463
- Joined: Sun Oct 08, 2023 5:06 pm
- Location: Chelmsford, Essex
Re: Female Common Blue - Odd behaviour
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?
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:
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.

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?
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:
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.



David Lazarus
Chelmsford, Essex
Chelmsford, Essex