Pupae cases built by ants

[Dave Horsley]

The ants with this potential pupa covering?

I posted this on the General forum but had no reply so I thought I would try the species forum for Chalkhill blues.
I went looking for Chalkhill blue larvae last week - found some but also found some ants tending a small, brown, open case which just looked perfect for a larva to pupate in. There was a lot of ant activity. I don't think it was last year's case so do the ants build the cases to put the larva/pupa in? This seems a bit unlikely and requires some foresight. Does anyone out there know whether this might be a possibility?

[Padfield]

I saw your post, and thought the photo was brilliant, but I didn't know the answer, so didn't reply. I'm sure someone does, so keep this one alive!

Guy

[Pete Eeles]

Hi Dave,

There's no description that I'm aware of that would suggest that ants build cocoons for any species - any cocoon being built by the larva itself.

Cheers,

- Pete

[Dave Horsley]

Jeremy Thomas says in The Butterflies of Britain and Ireland

lives concealed in an earthen cell moulded by ants beneath the vetches

which is exactly where I found this.
Dave

[Pete Eeles]

Thanks Dave - I'd not read this. I also wonder what Jeremy means by "moulding" and "earthen cell"

Cheers,

- Pete

[Dave Horsley]

It would be nice to think that is exactly what the photo shows!
Dave