The world-wide demand for pesticide is predicted to grow to a staggering £35 billion by 2014, and with so much money being spent on killing off pests, there are times when it’s hard to remember that not all insects want to bite or sting you, or compete for your food! Fortunately alongside all the freeloaders, there are some incredibly beneficial insects to be found roaming the countryside – largely unsung heroes that between them are responsible for doing a huge amount of good in our gardens and fields. Here’s the list of our top five.
OK, so there are no surprises here; everyone but everyone knows about bees. They’re nature’s good guys; if they sting, it’s only as a last resort, and even then they really, really don’t want to – but have you any idea just how much good they actually do?
According to the government figures, if you had to pay someone to pollinate all the plants they do, you’d be facing a bill of over £200 million each year – and the sale value in the shops of the food they pollinate stands at a whopping £1 billion. That’s in the UK alone and it only takes into account honeybees – not the amount of work done by the huge numbers of bumblebees and solitary bees that also live in Britain. Small wonder that Albert Einstein is quoted as saying “if the bee disappeared off the surface of the globe then man would only have four years of life left. No more bees, no more pollination, no more plants, no more animals, no more man.”
The bee has got to be the number one beneficial insect of all time!
If ever an insect looked like a cartoon character, then it’s the familiar red and black spotted ladybird. It’s the appetite of this well-known bug for aphids that makes it such a much-loved favourite amongst gardeners and both in its adult form and most particularly during its time as a grub, the ladybird is a voracious predator of greenfly and their relatives.
Encourage these instantly-recognisable insects to your garden with one of the purpose-built shelters on sale in most garden centres and DIY shops, and you should find that the number of aphids sucking the life out of your plants will soon start to drop.
Leave a light on and the curtains open during the summer and sooner or later, a lacewing or two will turn up against the glass, looking like a diminutive green mantis, with its iridescent golden eyes and those large, intricately veined wings that give it its common name.
From an aphid’s point of view, lacewings are only one step behind ladybirds in the top ten list of bugs best to avoid, largely since lacewing grubs munch their way through huge numbers of greenfly on their way to growing into adulthood. Although once they are fully grown, they abandon their aphid-eating ways, their single-minded determination to consume as many as they can as larvae earns them a well-deserved mention in any list of beneficial insects.
Often confused with bees or wasps, hoverflies are commonly seen flitting swiftly from flower to flower in warm weather, typically with the sort of mid-flight hovering skills that you normally associate with dragonflies – or perhaps helicopters! It’s this feature that lies behind their common English name, but it is their love of flowers, especially yellow ones, that gives them the name ‘flower flies’ in America – and given some of the recent studies by scientists, our friends in the US could be onto something. It seems hoverflies may play a much larger role in pollinating many garden and commercially important plants than was previously thought. While this alone would make them strong candidates for inclusion on the beneficial insect list, they have one claim to fame that has been known about for years – and it’s another case of bashing those pesky aphids!
The females of a number of kinds of hoverflies seek out plants which are being bothered by aphids to lay their eggs, and once the maggots hatch out a few days later, they’ll spend the next three weeks or so happily tucking in to the meal. Talk about precisely targeted pest control!
The famous biologist, Charles Darwin, once remarked that one of the greatest things that his study of the natural world had taught him, was that God was really very fond of beetles, and it’s easy to see why. There are more species of insect on the planet than all the other kinds of animals put together – and most of them are beetles. In fact, they’re just so common, that we often overlook how useful they can be.
Many kinds, particularly the likes of ground beetles and rove beetles, are natural predators on a range of insects and other invertebrates that we view as pests, including – yes, you’ve guessed it – aphids along with a number of hungry caterpillars and grubs. Some of the larger varieties, such as the fearsome-looking Devil’s Coach-horse, will even attack and eat slugs, a habit which understandably tends to endear them to many of Britain’s gardeners.
As a group, insects do a staggering amount of damage to crops and property around the world, but it’s nice to know that they’re not all bad and that human beings have a few beneficial bugs on their side!