To me this looks rather like the wonderful Deaths Head Hawk Moth Caterpillar Acherontia atropos the largest hawk moth found in the UK. Certainly worth loosing the Jasmin over, although I belive they prefer potato plants. http://ukmoths.org.uk/show.php?bf=1973&map=true. I am so jealous.
Sure is the Deaths Head Hawk-moth - can you email me at firstname.lastname@example.org details of the locality, your name, date etc. and I will pass this interesting record on to the lepidoptera recording scheme.
Although this impressive moth is a known, though occasional migrant, to the UK there has been a lot of captive breeding of this species in the UK with inevitable releases of adults. Still a superb find though and no way of telling if these are the progeny of a natural migrant or released UK bred stock.
Along with Lewis I am also quite jealous.
But you may exclude a phenomenally rare ichneumonid or other parasite.
A case in point - a good friend of mine came across Goat Moth larva, a nice find, and took it home to rear through. Almost a year later instead of an impressive goat moth two spiky tachinid flies emerged from the pupa. Now these flies, which as a group are parasitoids of other insects, are specific parasitoids of the Goat Moth and turn out to be only the second time that this species of fly has been found in the UK. The only other specimens known are 1 ex here in the NHM collections and 2 ex in the Oxford collections.
Caterpillars have flies upon their backs to bite 'em and rarer caterpillars have rarer flies and so ad infinitum ..
Thanks very much for your responses. I feel privileged to have a couple of these caterpillars in the front garden. Is there anywhere you can recommend where I can find out more about the lifecycle of the Deaths Head Hawk Moth?
The name rang a bell - I think this moth featured in the film "Silence of the lambs"
'It rubs the lotion on it's skin'. Yup the Deathshead Hawkmoth played quite a pivotal role in The Silence of the Lambs, although this was the Asian version Acherontia styx. There is plenty of general information available on the web on this great moth. How big are the caterpillars at the moment?