Blair's Shoulder-knot isn't some terrible muscular problem affecting the Prime Minister, it's a moth that arrived in Britain in 1951 and has been spreading northwards ever since, arriving in Cumbria in 1996. This was a Dr. Blair, an entomologist who worked at the British Museum and retired to the Isle of Wright to discover this and two other moths in the space of nine years. By this time it had unfortunately become common practice to name moths, rather boringly, after the discoverer.

Much more interesting are the 18th century names chosen by the early lepidopterists. Before the 1700's no-one had bothered to distinguish moth species. In Cumbria all were apparently called 'owls' or 'bustards'.

The first species to acquire individual names were those with large distinctive larvae, like the Elephant (hawk moth) with its grey trunk-like body and head and the Puss with its cat-shaped saddle complete with ears. The Drinker had an alleged habit of repeatedly dipping its head into droplets of dew and, perhaps the oddest, the Goat, acquired its name because its larvae emit a strong unpleasant smell ....of billy-goat!.

A few species acquired names based on the colours of the adult, for example the Magpye (sic) and the Fox. One species The Egger (now Oak Eggar) was so named because it pupates within a large egg-shaped cocoon on the ground.

By the 1770's a few hundred species had been identified and it must have become harder to think up obvious names, so the Gentlemen entomologists turned to Georgian dress codes for their names. So here we get the sombre Quakers, shining Satins, furry Ermines, raised Brocades and, for the ones they couldn't be much bothered with, the Rustics in drab brown garb! Back in upper class mode and the home, there are the Footmen (wings folded straight back like a liveried servant standing to attention), the Wainscots (the texture of oak panelling in the drawing rooms of the day), the Mochas (the pattern of a semi-precious stone) and the pretty Carpets.

About this time it was realised that several species of moth had a prominent projection to the trailing edge of the forewing, very noticeable when the moth was at rest with wings folded back. They became known as the Prominents - of the ten related species found in the UK eight are recorded in Cumbria. My favourite has to be the Iron Prominent. Its iron-grey forewings have red-brown smudges that suggest it is going rusty. Indeed it was originally called the Rusty Prominent and I wish that name had stuck - very appropriate for the Lake District climate.

Butterflies, like plants, had many local names, which underwent many changes over the centuries before there was some national consensus. In contrast moths had a minority following and most of the names have remained largely unchanged from the beginning. Two rather charming ones that have changed, however, were given to two of our green moths. The Common Emerald was for some reason originally called the Small Green Housewife, while the Blotched Emerald (recorded for the first time in Cumbria in 2000 by Rob Petley-Jones) was the Maid of Honour (a pun on Honor in London where it was first discovered).

As scientific observation improved and it was realised that many moth species had very specific larval food plants, names were sometimes chosen to reflect this. So we have the Butterbur, the Swordgrass (an old name for sedges) and the Sallow (see photo right). But this doesn't always prove to be a reliable guide, as sometimes they just seem to have got it wrong. The Spinach may have been found in gardens but its food plants are red and black currants, the Alder moth feeds on many tree species but rarely finds Alder and the food plant of the Knot Grass is not Knot Grass!!

A species that does feed on Knot Grass is the Shuttle-shaped Dart. Now that's a literally descriptive name that takes some beating. Darts have a dart-shaped streak on the forewing and we have a whole string of them in Cumbria with self-explanatory names - Garden Dart, Double Dart, Deep Brown Dart, Sand Dart, White-line Dart etc. One exception is the Archer's Dart, which sounds like it belongs to someone who shoots arrows or darts but, as its a specialised coastal species discovered late on, it got one of those boring names (of a person). Another relative, the Northern Dart, was last recorded in Cumbria in 1981, but then not many people lug their moth traps and generators 450 metres (1500 feet) up a mountain in the middle of the night, which is where one might expect to find it!

Finally, after reading all this, I hope you don't share the fate of one of our scarce local moths and be described as the Confused. Now there's an unhelpful name if ever there was one and goodness knows who thought it up and why!