When I was mystified the other day by what turned out to be the common and regular visitor at this time of the year, a Straw Underwing, one of the extremely helpful experts on the Upper Thames Moths blog, Martin Albertini, described the species as 'a major banana skin', because the key to its ID lay in its hindwing, so often hidden when a moth is at rest.
I am not sure what I can do about this, because getting a moth to reveal its pants, as it were, usually involves annoying it so much that it flies away. But occasionally even skittish moths, such as the Willow Beauty in my first two pictures today, allows a longer look, especially when they choose to perch on the light trap's transparent cowl, thus revealing their underwings.
That is the view in the first picture; not an ideal study because my cowl is so old and bashed about, but it gives a pretty clear impression. The second picture shows the species' familiar topside which is what I normally see.
The hindwing problem is less easily solved; an issue which did not arise in my younger days when cameras were so hopeless for close-up work - at least the ones which I could afford such as the Brownie 127 - that killing specimens was the general rule. You then 'set' them by spread-eagling them on cork boards with a slot down the middle to take the insect's body. Here are some examples from a visit I paid to Sulawesi in Indonesia where the butterflies are among the most striking in the world:
I am adding a close-up of the wonderful blumei Swallowtail in the top left-hand corner which I caught after a dramatic and prolonged hunt along a jungle river. Killing is out of order now except for serious scientific researchers but I am happy that this butterfly and its colleagues in the display case have done a lot of posthumous good, through enthralling visitors and interesting quite a few of them in a subject which they had disregarded previously.
Back at home and up to date, my musings on the trap cowl prompt me to show a couple of visitors this morning: a Poplar Hawk using the decaying remains of Sellotape on a crack repair to cling upside-down, and a Swallow Prominent whose presence on the outside of the cowl - unmolested by birds which seem unable to detect a completely passive moth -had dried up the surrounding dew.