Newly-minted large yellow underwing moth

We found this large yellow underwing moth Noctua pronuba crawling across a pavement just after it had hatched from its pupal case. At that point the wings were very small - about one third of the length of the body - but by the time I'd carried it home, after half an hour later, they had almost fully expanded.

It sat on a leaf holding its wings vertical above its back for the final stages in their development, revealing the bright yellow underwings and also ....

... this small bristle on the underwide of the lower wing, which seems to lock into a slot on the underside of the upper wing - presumably a mechanism for holding them together in flight to produce a larger, more rigid wing surface.

Here the wings are about 90% expanded and you can see the yellow 'flash coloration' that is thought to alarm and deter predators when they disturb the moth.

While it was extending its wings the moth also had a practice uncoiling of its proboscis.

Finally, here it is, fully winged and ready for flight. A dull-looking moth until you disturb it and it exposes those colourful underwings.

These moths are very vulnerable in the hours between their emergence and the final development of their wings - click here for images of one that was not so lucky....

Unlucky Moth

Large yellow underwing moths have been hatching out all over our garden during the past week but this one chose a very bad moment to emerge from its cocoon - just as a passing wasp was looking for a meal. Although they have a liking for sweet things, wasps are ferocious carnivores and kill vast numbers of garden pests, which they feed to their brood. They'll tackle prey much larger than themselves and I've several times seen a wasp kill a caterpillar and chew it into bite-sized chunks small enough to carry back to the nest. I've never seen one tackle something as large as this moth. I noticed the moth lying on its back on the path, fluttering its wings weakly - and then I saw the wasp attacking it, repeatedly stinging its prey's abdomen and trying to chew off the moth's head and legs. At this stage the moth was still fighting back and briefly succeeded in dislodging its attacker. The wasp seemed to be very irritated by the caterpillar hairs on the cocoon (still visible in the top photo under the tail of the moth) and by the hairs on the moth's body, and it stopped its attack several times to clean the hairs off its eyes and antennae (bottom photo). Then it retreated for a while, waited for the venom to take effect, then returned to finish its meal. After about half an hour, all that was left of the moth was the wings and holow thorax. Its adult life span had been measured in minutes.....