The ladybird, that neat little orangey-red creature with black spots, which looks so pretty on your plants, is a great meat-eater and can polish off 50 aphids in a day, according to an organic gardener. But what sounds so unlikely is the news, from the same source, that it can clear a beach of humans.
The writer, Val Bourne, in The Countryman for June/ July, has this to say: "If you've ever been trapped on a Norfolk beach in August, you'll have felt the power of their jaws. They travel across East Anglia in huge swarms, feeding on the aphids found on crops until they reach the sea. After several moments of confusion, when they hover over the water's edge, they turn inland once again - with a vengeance. Deprived of food, they bite unsuspecting holidaymakers. The straw mat you were once lying on is quickly rolled up and used as a weapon of defence. They are discerning creatures - they go for the ladies, attracted by their female hormones (or is it their higher body fat!). When a swarm descends, the beach empties within a couple of hours".
It may be possible to buy ladybirds through the post from Britain, but in America, according to this article, ladybirds are a big commercial crop, sold by the bucketful, and raised by special ladybird farmers. A gallon bucketful holds about 135,000 dormant male and females. Apparently you release them in spring just as blossoms open. They breed quickly and their grubs, described as "lizard-like" feed on aphids, too.
The Californian fruit crop was once saved by ladybirds, and the creatures are imported from American ladybird farmers by fruitgrowers from South Africa, Australia and South America. Your average gardener here may only distinguish a couple of different ladybirds, but this article says there are about 40 species in Britain and we may not be so different. But worldwide there are three hundred. They belong to the beetle family of Coccinellids. The ladybird's colour, says the writer, is Nature's way of saying "I don't taste very nice", so they tend not to get eaten by fellow creatures. If attacked, they have a secret weapon: "they lie on their backs and squirt smelly liquid from their legs." They live one year, mating in the spring after hibernating; the female laying her eggs on a leaf with plenty of greenfly. One female can lay up to 500 eggs.