Plagues of aphids, the bane of gardeners and farmers, have a use, after all - they are being recruited by weather forecasters to predict summer storms.
Meteorologists at the University of Reading have discovered that billions of tiny greenfly, blackfly and other bugs floating around in the air can help them to forecast where showers and storms are likely to break out.
Localised showers are almost impossible for weather forecasters to pin-point; a downpour in one place can leave somewhere else a few miles away completely dry, but accurate forecasts would help to prevent disasters.
Although weather radar is useful, it shows only where the rain is actually falling. But one telltale sign of an imminent shower is flows of humid air converging at one place.
On a typical summer’s day sea breezes from the coast can penetrate inland and crash into other winds. Those collisions thrust the air upwards, like cars crashing head on, and their moisture condenses into clouds and eventually rain. When Reading scientists pointed their weather radar up at clouds they noticed their signals caught an interference from the air below.
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“We always had radar echoes in the lowest part of the atmosphere, and we tried to get rid of them,” explained Anthony Illingworth, of the university, “but then we realised they were insects.” These were tiny insects, mostly aphids, floating like tiny balloons in the air up to two kilometres (1.2 miles) high and they made excellent tracers for the airflows into the clouds.
“We found that the leading edge of clear, cooler air from sea breezes swept up insects like a brush,” explained Professor Illingworth. “The same happens when cold air comes down from a thundercloud.”
Once the flow of insects is located, a Met Office team based at Reading is using an experimental, powerful, computer model to predict showers and thunderstorms down to 1.5km detail on a map, about three times more precise than current forecast models.