www.ukbutterflies.co.uk

Can anyone tell me what type of caterpillar this is? Photographed on nettles in West Yorkshire recently.

Hi Dormousey

Welcome to the site. I would guess that it is a Peacock but if I am wrong I am sure someone will shout.

My initial reaction was Peacock, but the light colouring near the prolegs (near the head) leads me to think this is possibly a dark Small Tortoiseshell. Less likely is Painted Lady or Red Admiral (especially since it's out in the open!).

Cheers,

- Pete

By a process of elimination, and looking at the available features, I would put money on this being a very dark Small Tortoiseshell larva. In fact it would the the darkest dorsal view I have ever seen.

Vince

I've seen some dark Small Tort larvae this spring. The spotting pattern looks more Small Tort than Peacock and the head 'cheeks' look wider than on a Peacock larva. Caterpillars are hard enough without these sort of variations!

I agree with small tortoiseshell. This chap stowed away in my camera case in 2009 and because it wasn't even on foodplant I had no idea what it was:



I gave it a place to pupate and a month-and-a-half later this popped out:



Guy

Thanks Guy
Your photo clearly shows the line that runs along the back of the larva (which Peacocks don't have). Peacock larvae also have much larger silvery spots and different spines. In any case, a clearer side view would have shown further characteristic features which distinguish between the species.

Vince

Thanks for your replies. I have a side view here.
I'd also noticed the other caterpillars I'd seen a few days earlier had appeared to have shrivelled up. Not sure what happened there.

Your caterpillars haven't actually shrivelled up; they've just shed their skins or moulted, and moved off to continue to feed elsewhere in the nettle patch.

M.

Oh that is good. I was hoping it might be something like that but I wasn't sure if caterpillars shed their skin.

Dormousey,

As already confirmed, your caterpillar is a Small Tortoiseshell. I have seen a couple of dark coloured ones this year too and would certainly concur that the Peacock has distinctive white/silver spots which your example hasn't.
The larvae will have a total of four moults (instars) before they finally pupate.

I have been blessed with some Peacock larvae on nettles in my garden this summer, which I have helped shield from preying blackbirds in order to follow their instar cycle. They have now wandered off to pupate (of which I have located one). In due course I plan to share my photos of the process from caterpillar to Butterfly.

Regards Kev