July 31, 2009

Ladybugs Plague Denmark

After the American Century

"The air was filled with countless dancing gnats, swarms of buzzing flies, ladybugs, dragonflies with golden wings, and other winged creatures." -- Hans Christian Andersen, "The Marsh King's Daughter"

A veritable army of ladybugs has descended on Denmark, as often happens at this time of year. Other nations suffer from plagues of grasshoppers or locusts, and for decades Americans have worried about the northward progress of the killer bees. But as befits a small and peaceful nation, Denmark suffers a more genteel nuisance, as swarms of ladybugs invade the land.

This morning, I found ladybugs all over my car, crawling vigorously around my garden, and diving by the drove into my rain barrel. They seem to have no natural predators at this time of year, proliferating exponentially. Based on the number in my side yard, I conservatively estimate that there are at least five per square meter, more than 1,000 in my small yard alone. Extrapolating from this admittedly inadequate sample, it is possible that there are somewhere between two and five billion ladybugs here at this time of year.

However, this may be too small an estimate. A neighbor back from a vacation in the wilds of Jutland reported seeing clouds of ladybugs at dusk, turning the sunset a darker red. Strangely, they often swarmed on the beaches, attacking German tourists, nipping their sunburned skin. Apparently they cannot resist the smell of certain suntan lotions.

Scientific studies are not yet complete, but it appears that the ladybug plagues are intensifying as a result of global warming, which prolongs their mating season, making it possible to produce at least one additional generation each summer. In wet years, their food supply is also greater. Longer and wetter summers apparently account for the sudden multiplication of ladybugs in late July. Since ladybugs consume aphids and mites, gardeners the world over are glad to have them around, and one can only speculate over whether there is some unintentional connection between the policies of the current Danish government and what must be an enormous production of garden pests sufficient to feed these beneficent predators. (Polling is incomplete, but the vast majority of ladybugs appear to be social democrats.)

New species of ladybugs have also invaded Denmark, however. There are about 5,000 kinds of ladybugs worldwide, and I make no pretense to being able to identify them. As one might expect, some are from Southern Europe, brought home by Danish tourists in their cars or in their suitcases, usually as unnoticed eggs that hatch after arrival. However, there are also more exotic ladybugs, including one large, individualistic North American variety. There is also a Chinese one that is a bit flatter and rounder, with stubby wings for steering, which appears to spin like a miniature flying saucer.

In my back garden is a multicultural ladybug nation, a globalized phenomenon, a trillion footed buzzing society that has chosen Denmark as its preferred destination. Within a few days, I expect my garden to be striped clean of aphids, mites, and insect eggs. I expect they will also drive away any lurking conservative politicians. And as the sun sets over Denmark, look for the telltale reddish-black cloud of ladybugs heading for another summer evening at the beach.