Green stripey caterpillar

[Mischa]

Hello, I'm far from an expert, just have developed an interest in insects, as long as not too tiny or difficult to identify!

Last Sunday I encountered a large caterpillar, about an inch long, green body, with black bands (horizontal). On the bands were yellow/orange spots. It was on a path and at first I thought had been partly crushed because it seemed to be oozing fluid. But on closer inspection this looked like a load of greenish jelly, like a lot of eggs (but caterpillars don't lay eggs, I know that much!). It seemed to be coming out of either front or back end (stupidly I didn't look closely enough) and the caterpillar itself looked intact. I wasn't able to take a photograph. Looking at photographs it most resembles a swallowtail but I know it can't be that because of the location. I read on this site that there are some migrant swallowtails but that seems unlikely as well. Photographs of emperor moths are also very similar, especially the bands, but as far as I recall it wasn't at all hairy (but again I may not have looked hard enough).

The location was Walthamstow Marshes, NE London. The habitat where it was is mostly long grasses, there is also vetch, michaelmas daisies, brambles, reeds, purple loose strife, birds foot trefoil, thistles, as well as others. There are small heath butterflies, blues, meadow browns, and others that flit around and don't rest. I've never seen anything like an emperor moth (now knowing what they look like) but maybe it is a night flyer.

Was it most likely an emperor? And what about the strange oozy stuff?

Regards

Mischa

[bugboy]

Ooooh Walthamstow Marshes, my local patch ! When I was reading your description I must admit swallowtail and Emperor moth were my first guesses but I've never seen Emperor moths there (it's been my local patch for 6 years now), although thats not to rule them out, and as you say very unlikely to be a swallowtail. Emperor Moths fly day and night and this is the right time of year to find their caterpillars and they do feed on a variety of plants, many of which do grow exactly where you say you found it.

From your description of the location I think I know almost exactly where you saw it too, I may take a look in that part next time I'm there, probably in the next couple of days with the bloody tube strike stopping trips further afield. From your description I can't think of anything else it could be....

[Essex Bertie]

Emperor moth would be my guess too. They seem quite locally distributed in Essex away from the sea walls, but there are recent records for large unimproved grassland sites in urban areas - Wanstead Flats and the Beam Valley in Dagenham. So near Walthamstow, they probably still use the heaths in Epping Forest and the river valleys for breeding.

[Mischa]

Hello thanks to both. Bugboy - it was on the field that is between Horseshoe Thicket and the railway embankment/bridge, not very far from the gate that leads from the river pathway near the railway bridge, the path that kind of goes diagonally north easterly (roughly). I was actually concentrating on blackberrying that day (bumper year) so it was a bonus to see something I'd never seen before. So if it was an emperor, it sounds like they could be spreading.

[bugboy]

Hello thanks to both. Bugboy - it was on the field that is between Horseshoe Thicket and the railway embankment/bridge, not very far from the gate that leads from the river pathway near the railway bridge, the path that kind of goes diagonally north easterly (roughly). I was actually concentrating on blackberrying that day (bumper year) so it was a bonus to see something I'd never seen before. So if it was an emperor, it sounds like they could be spreading.

Thats precisly where I thought you described! Might go there tomorrow and have a good old search, some sun has been forecast and it's been a fare few years since I've seen an Emperor Moth at any stage!

[bugboy]

Hi Mischa, I had a wander over there today but no luck with any green stripey caterpillars. To be fair it was a bit of needle and haystack scenario though. You're right about the bumber crop of blackberries though!

taste good as well