As any of my readers who follow me on Facebook know, a few days ago I had a beautiful Jersey Tiger Moth (Euplagia quadripunctaria) in the garden; in fact feeding on our buddleia. As my photograph shows, these are very distinctive creatures.

I love seeing them, not just for their beauty but also because they are a success story of something extending its range.

As you might guess from their name they originate (as far as the British are concerned) in the Channel Islands, although their range extends across much of Europe and western Asia.

Until relatively recently the moth was absent from the British Isles. However they are now found along the southern coast of England: first in Devon, then Cornwall. While some moths are likely migrants from the Continent (or Channel Islands), they clearly are now breeding here as they have extended their range to much of southern England and London.

The first one I saw was in Lyme Regis, on the border between Devon and Dorset. It was sitting, bold as brass, on a bedding plant in a park. This was in 2006. Since then I’ve seen an odd specimen most years here in west London, and this year I have a couple of other reports of the moth in the local area. On Twitter there are lots of recent reports of sightings from around southern England; I’ve even seen a mention by one enthusiast with a moth trap who had over 3 dozen trapped one night recently. (Of course I can’t now find that post!) They do seem to be becoming more common and spreading slowly northwards – too much for them all to be migrants.

For the UK they’re a fairly large moth, with a wingspan of 50-65mm. Like most moths they fly largely at night, although they do fly during the day. I spotted the one I photographed because of the movement of its flight. They do also seem to have a habit of resting in the open in rather conspicuous places on leaves, tree trunks etc.; presumably they rely on their warning colouring for protection, if not camouflage.

As well as the bold black and white forewings, their hind wings are a bright reddish-orange. There is though a colour morph with yellow hind wings; and a melanistic form with all black forewings.

Now instinct says that such a boldly coloured moth would be a garden pest, but actually they aren’t. The larvae feed on a wide variety of plants such a nettles, raspberries (OK not so good that one), dandelion, dead-nettle, ground ivy, groundsel, plantain, and more. The larvae are mostly black and (often gingery) brown and hairy. They overwinter as small larvae. The moths are generally on the wing from mid-July to early-September.

What I find interesting is that every image of a Jersey Tiger I’ve ever seen appears to be female. How do you sex a moth? Well with most species the males have frilly antennae to pick up the female’s pheromones – because shagging, y’know! But there are exceptions to the rule and wonder if the Jersey Tiger is one of them.

You would think that something this highly coloured and day-flying would be a butterfly. But no, there are day-flying moths. And there’s an easy way to tell a moth from a butterfly: butterflies have small knobs on the end of their antennae; moths don’t. Again I’ve no doubt there are exceptions, but I don’t off-hand know of one.

Don’t confuse the Jersey Tiger with the Garden Tiger Moth (right) which has more broken, less linear, patterning to the forewings and a brown furry head. The caterpillar of the Garden Tiger is what we always knew as kids as a Woolly Bear. Garden Tigers do seem to have become much less common over the last few decades. There’s also the Scarlet Tiger Moth in UK, but that is even more different, is around earlier in the year, and is quite locally distributed.

As always there is a lot more information on the internet and Wikipedia is as good a place as any to start.