Swirling swarms, virgin queens and carrier ants
Flights of fancy: winged ants. Illustration: Michael Viney
In all that heat last month, and near enough to the silly season, these islands conjured not a single insect “plague”. No kamikaze squadrons of water beetles hammered the bonnets of shiny cars, mistaking them for ponds. No clouds of migrant ladybirds sent bathers shrieking from the beaches. No hordes of wasps pursued lickers of ice creams as they fled from St Stephen’s Green. (Indeed, where are the wasps? I haven’t seen one for weeks.)
For a really significant Irish insect plague, indeed, one could go back to 1688, when millions of cockchafers – “maybugs” – arrived on the coast of Connemara, borne, most improbably, on a southwest wind. Their locust-like progress inland, as far as Headford, was recorded by Dr Thomas Molyneux, one of the most active and observant Irish naturalists of his day.
“A short while after their coming,” he wrote, “they had so entirely eat up and destroy’d all the leaves of the trees for some miles round about, that the whole country, tho’ it was in the middle of summer, was left as bare and naked as if it had been in the depths of winter [and] the grinding of the leaves in the mouths of this multitude all together, made a sound very much resembling the sawing of timber . . .”
In due course, their “spawn” became fat white grubs underground, devouring the roots of corn, so that “the poorer sort of the native Irish (the country then labouring under a scarcity of provision) had a way of dressing them and lived upon them as food.” This could interest the current advocates of mass insect consumption, if already echoed in the historical diet of Australian Aborigines.
The spectacular migration of cockchafers, as Molyneux guessed, originated in France and stemmed from their own search for food. An abundance of food, on the other hand, can produce a population explosion. In 2009, millions of painted lady butterflies arrived in Britain and Ireland – “snowing” butterflies in parts of this island. The original source was the Atlas mountains of Morocco, where the wettest winter in decades had produced a forest of thistles, the food plant of the butterfly. The extra thousands of pupae launched the first northward pulse of this continuously-breeding species.
In Ireland, a totally natural and regular mechanism produces an annual swarming of ants in the sky, a phenomenon celebrated over Dublin in high, ecstatic swirlings of the city’s swifts, starling and gulls, feasting as they fly. It occurs over several afternoons about now; may, indeed, already have happened, if humidity, windspeed and temperature were right. It is triggered by an astonishing synchrony of body-clocks in millions of ants in thousands of separate colonies.