Thursday, 5 May 2011

Singing the blues

Blue. I pine for blue in UK moths. In vain. There is a scrap of it on the Lesser Angle Shades and a couple of pale mauve ribbons on the very rare Clifden Nonpareil which I will be extremely lucky ever to see. I have wondered several times before on this blog about the reason for its absence and promised to investigate when I retire. I am already sure, however, that the answer has something to do with daylight, because we have a great collection of beautifully blue day-flying UK butterflies.

Here's one, above, the Holly Blue, and even in a photo as bad as mine, you can see the lovely colouring of its forewings. Unfortunately, like most blues, it is reluctant to show these when at rest and so I have had to make do with the powdery underwing, dotted with dark blueish-black spots. There can be a delicate sheen of brighter blue near the insect's body, caused perhaps by reflective mirror or prism scales, but needless to say I have not managed to capture this. I think my camera was fazed by the brightness thrown off by the underwing in our continuing sunshine.

This butterfly is 'mud-puddling' at the edge of our pond. Not a very salubrious spot but good for the insect to draw up minerals through the disagreeable looking 'nectar' of pond sludge. It was absolutely absorbed in the task and lost all the skittishness which is normally typical of small butterflies whizzing between flowers. So I had time to get the picture. I have seen this process on a very large scale in Indonesia, with swordtails and swallowtails in their hundreds on the edge of jungle rivers. When you disturb them, they fly up like a blizzard in reverse.


Banished To A Pompous Land said...

I don't know what it is about blue in moths either Martin. Its not just over there, I checked BugGuide and it seems very very rare. All I found was:

Even that is edgeing more into the violet than the pure blue.

I was thinking perhaps something to do with low light visiblity, maybe blue doesnt show well at night... or is TOO visible to predators. But then why not more blue day-fliers?

Anonymous said...

Hi B

Interesting points about high or low-viz which is pretty crucial to moths' survival. I shall keep checking the scientific data but haven't found anything beyond Prof E B Ford's recommendation in his great book Moths in the Collins New Naturalist series that this subject should be more fully researched!

all v best


Toni said...

We once found a Holly Blue 'mud-poodling' - drinking from the muddy legs of our standard poodle Archie. A real contrast of muddy dog ruffian and tiny jewel butterfly.

Anonymous said...

Hi Toni

That's a great variant!

I often wonder what butterflies (and moths) see and how much than can detect of us and the potential threat we pose - or the potential for a snack. It's a good moment when one is trusting or curious enough to alight on a sleeve - or a poodle's muddy leg

I'll remember your story - thanks!

warm wishes