Dear Readers, Jersey Tiger moths seem to have been popping up almost everywhere in the East Finchley area this week – with their Vulcan Bomber shape and bold black and white wings, they’re a hard moth to ignore. The one below was on my kitchen window and had somehow managed to get itself behind a spider’s web. I don’t usually interfere with nature, but the web looked as if the spider hadn’t repaired it for a few days so I removed it, and the moth flew away into the garden with that startling flash of their red underwings. I suspect that they’re either unpalatable to birds or pretending to be inedible, hence their extraordinary confidence.
Jersey Tigers are still listed as ‘rare’ on the Butterfly Conservation website, but they seem to have increased markedly in numbers where I live in the past few years. Some could possibly be migrants, but I have a gut feeling that they’re established and breeding, not just in Devon and Dorset but right here in London. Climate change has led to warmer winters and so, as the species spends the winter as a tiny caterpillar it probably has a better chance of survival. However, a study in Austria showed that, as hot days increase, these moths (along with several other day-flying species) are increasingly being found in caves, presumably so they can find shelter from the increasing temperatures. Like most animals, Jersey Tigers have a fairly limited range of temperatures at which they can operate, so they may also be moving north because things are hotting up too much in southern Europe.
The caterpillars of the Jersey Tiger moth are what’s known as polyphagous, meaning that they eat lots of different plants. However, they seem to have a great fondness for Hemp Agrimony (which my garden is positively awash with at the moment), including stinging nettle, dead-nettles, borage, ground ivy, plantains and brambles. As the caterpillars hatch in September and pupate in May, it’s another reason not to tidy up too much in the winter, tempting though it is. All sorts of creatures are living amongst and inside those tatty plants.
Incidentally, Jersey Tigers look completely different from underneath – they have a kind of rosy glow (much like me after a brisk walk) but they are also have a pale and fleshy quality which is slightly unnerving (ditto). The wings look a bit like stained glass though, which is very pleasant.
So, I think that the Jersey Tiger is somewhat underreported in London in particular, and I would be very curious to know if any of you lovely Readers in the UK but outside London have spotted any. Incidentally, Butterfly Conservation’s Big Butterfly Count is on from now until 6th August – all you have to do is survey your garden/park/piece of countryside for 15 minutes and report what you see. And one of the insects that they’re asking you to look out for is, indeed, the Jersey Tiger, so hopefully we should get a better idea of what’s happening with the numbers. It will be interesting to see if it is travelling further north and west, or increasing its population. Either way, keep your eyes open for this striking new addition to our fauna.