Country diary: Hungry wasps have surrounded the willow tree

Langstone, Hampshire: Autumn is their true season, more than summer, as they go in search of their liquid dietDuring spring and summer, common wasps (Vespula vulgaris) feed their larvae dissected insects and carrion. In return, the developing young secrete a carbohydrate-rich sugary fluid for the attendant adults to drink - an exchange known as trophallaxis. By early autumn, a single nest can contain up to 10,000 sterile female workers, but just as the population reaches its peak, the queen stops laying eggs and the number of larvae rapidly declines, sending the colony out in search of alternative sources of sustenance. So, despite their reputation for plaguing summer picnics, it's at this time of year that wasps really make their presence known.While the larvae are carnivorous, the hourglass-figured adults subsist solely on a liquid diet. At first, they feed on nectar, but as temperatures cool and flowers begin to fade, they turn their attention to other sweet substances. In recent weeks, it's become impossible to enjoy a pint of cider in the pub's beer garden without an interloper or two crawling into my glass to sup the dregs. And every time I've attempted to gather fermenting windfall fruit from beneath my crab apple and pear trees, I've roused a rabble of erratically flying, inebriated insects. Continue reading...