Another Life Michael VineyThese are bluebottle afternoons. A window left open snares a passing female blowfly, sidling in to explore some promising hint of fetor or corruption.
A rolled-up copy of New Scientist thuds maniacally on to walls, doors, windowsills, dragging my arm after it, each time a nanosecond too late to escape detection in one of the myriad lenses of Calliphora vomitoria. The bluebottle's buzz is pitched, it seems, at a precise note of discordance with human creativity and concentration; only the bouncing of a football off one's gable can have quite the same galvanising consequence.
The buzz is related to her wing-beats, somewhere under 200 per second (those with an absolute sense of musical pitch can, it is claimed, tell the rate of vibration from the tone).
What helps the fly in its instant, darting manouevres is a "click" mechanism of the flight muscles, which stretch and contract automatically to control the position of the wings: just switch them on and they do the impossible beating up and down. (The curious may test this in a freshly-killed blowfly; press the wings downwards and they suddenly click all the way.) This more or less spontaneous function allows the fly to concentrate on flying sideways or backwards to escape the descending magazine.
The vomitoria bit in the bluebottle's name gives a generous clue to its eating habits, a treat, I presume, still in store for fans of the new grande guignol television genre of criminal forensics, already expert in the succession of blowfly eggs and maggots as aids to dating the corpse.
How one feels about insect necrophagy signals quite a lot about attitudes to nature. I have watched in half-appalled fascination as a large sexton beetle buried a dead wren in a corner of the greenhouse; its industry in scooping out soil particles from underneath the bird was utterly prodigious.
The dead wren was to serve as cradle and larder for the beetle's larvae, hastening, in the process, the recycling of avian base- materials.
John Stewart Collis, the Dublin-born, hands-on philosopher of nature (who wrote, most famously, The Worm Forgives the Plough), once steeled himself to monitor the entire process by which the bluebottle babies dismantled a dead bird he had picked up. His descriptions of them "building up new life in the abominable ferment of corruption" are enough to ambush the most robust sensibilities, but he insists that one goes through it without flinching. "The bluebottle is necessary," he says. "The bluebottle is good." It is this side of the fly's existence, however, besides its buzzing and its swarthiness, that tends to put them all beyond the Pale. Outside my window blooms a tall thicket of angelica, wild, native version of the garden herb that is used to make green curlicues on fancy cakes. It is an umbellifer, like cow parsley, with enormous, domed flower-heads that might have been designed by Buckminster Fuller. At this time in August, the little, lacy umbels that construct the domes are thronged with bluebottles, dark and crowded company for other blowflies in green metal jackets. They are all males and flower-lovers, probing for a honey-flow and innocent of all designs on the unwrapped Sunday joint.
Innocent or not, they are not much fun to watch. A few feet away, perched on rose leaf or oak twig, another, far more beguiling, insect occupies this sun-trap of a clearing between the hedgerow trees and the white house wall.
Quite as predictable as blowflies on angelica, or migrating swallows on the wire above, a red admiral butterfly takes up this territory in August and defends it against all invaders. With its path of grass and its clump of nettles (the food-plant of red admiral caterpillars), it is a classic habitat for the species and it is this, not any fancied "loyalty" of migrants, that explains the dependable annual presence of a territorial male.
While it waits to intercept a passing female, it dashes at almost any flying object of its own size: cabbage whites, meadow browns, even a queen bumble bee may swerve from the assault. Indeed, the butterfly's restless aggression outside the window can grow quite irritating at the corner of the eye. But when a female comes by, the courtship dance demands to be watched and wondered at; the insects rising in a spiral, a taut, flamenco weave of scarlet, white and black twirling up into the sky.
This has been a butterfly August, good for both native and migrant species (http://www.butterflyireland.com). The national influx of African painted ladies in late May and June will now have produced an abundant Irish generation. Watch, too, for the hummingbird hawkmoth, hovering on blurred wings to drink nectar from garden flowers.