Unseasonal fruit flies drive us all bananas

IS IT global warming? In these middle weeks of October, we have had fruit flies everywhere about the house, and even mosquitoes here and there.

They are the real early-warning mosquitoes, as encountered in the tropics, the kind which, just as you’re dropping off to sleep signal their arrival with a high-frequency whine close to the ear, telling you that you are on tonight’s menu and that there’s not a lot you can do about it short of turning the bedclothes into a tent and spending the night like an overheated Bedouin.

I haven’t been bitten yet — but they’re there, waiting, I know. There are 33 species of mosquitoes in these islands. Most do not bite people but of the biters, the most painful is the aptly named Culex pipiens molestus, for molest us they surely do. Happily, they are less common than Culiseta annulata, the main biting type, whose banded black-and-white legs are a ‘dead giveaway’, so to speak.

However, as any summer-evening turf-cutter, meadow-scyther, hill walker or pond angler will attest, mosquitoes are minor irritants compared with Biting Midges, the crepuscular swarms of which would drive a saint demented. Give me a mosquito injection any time, rather than a vicious midge bite. Mosquitoes are usually lone, stealthy freebooters; only the females bite; the blood is protein for egg development.

Midges, on the other hand — and foot and ear and neck and ankle — come in dense swarms. I recall, one evening, watching a man makes hay cocks in a mown meadow on Slea Head looking out at the Blaskets, whose entire upper body was barely visible inside a midges’ swarm.

Meanwhile, I am astounded by the miraculous multiplication of the fruit flies this October. The procreative energy of Drosophila funebris is legendary; females lay eggs every day. Thank God for it and yet no thanks to God either. They may be useful to science, but hey are mightily bothersome when they procreate with alarming multiplicity in the house.

Is it climate change? In my house, upstairs and down, fruit flies fill the air. Fruit flies hover over the open wine bottle on the table and, as you are about to lift your glass, the odds are you will spy one floundering on the surface, probably inaudibly screaming for help, and you either rescue it delicately with a small fingertip and flick it at a spider web or throw away the wine.

Regularly, fruit flies drone past your nose or between you and your screen, half asleep or half drunk, and you can’t stop yourself but throw out your open palm and then snap, knowing full well that when you open it, there will be nothing there and the fruit fly will be nowhere to be seen.

But, never mind. A few minutes later, another will hover before your line of vision and you will waste your energy once more. Soon, you will begin to reflect that it may be the same fly coming back again and again to annoy you. This makes you swear that you’ll get it next time: however, if you begin to snatch at the air too often, what will people think? My theory is that the air displaced by my open palm shooting out and snapping shut blows the fruit fly an inch out of my grasp. It banks, and recovers its balance, and hovers serenely away.

We thought the windfalls brought in from the orchard of an old estate was the reason for the influx. Decades upon decades of apples rotting into the soil would have generated multitudes of insects living in symbiosis, useful to the trees, the trees useful to them. Mosquitoes have been around for 170 million years: fruit flies in their myriad, hovering over windfalls, probably as long. They may have evolved little but, now, because they have especially large salivary gland chromosomes and short life spans they are the main aid for geneticist scientists working on ageing, Alzheimer’s, diabetes and heart disease.

By altering their genes, some flies have been given a life up to 85% longer than the norm — from 50 days to 85 days. However, the research isn’t so much about helping us live to 120 as preventing disease.

Hormones may eventually be used to alter the ageing process, and gene alteration in fruit flies points to new advances in longevity, thinness and the mechanisms of sleep. Most fruit flies sleep 12 hours a day but there are minisleepers who manage on much less.

However, they die younger, all burnt out, I suppose, having crammed the same number of hours of activity and procreation into fewer days.

All this goes to prove that while exercise is good, saving energy also pays dividends, and grabbing at passing fruit flies may well shorten one’s life.