Good Vibrations from Bugs
Or, How Biodiversity Keeps Your Garden Growing
Last spring I saw a commercial on TV where a woman opened her screen door and was instantly accosted by the amplified sound of an unseen flying insect that may have been trapped in the mouthpiece of a megaphone. The announcer advised the viewer of the benefit of frantically eliminating every outdoor insect you come upon. While using the advertiser’s product the woman has developed the peaceful look of a Stepford wife. With propaganda of this nature, it’s no wonder that there is a hysterical fear of all insects. But the truth is that spraying pesticides indiscriminately is the worst thing you can do for your garden.
Now, I’m not saying that there aren’t insect problems such as mosquitoes and ticks, but even that problem isn’t diminished with hand-spraying every insect you see.
For anyone on the receiving end of the huge advertising budgets of multi-billion dollar toxic chemical companies it may come as a surprise that the beneficial insects in our yards and gardens far outnumber the pest insects. As a matter of fact they keep harmful insects in check by parasitizing or feeding on them. Many insects also become a part of the life cycle of the plants by acting as pollinators. When we use chemicals to rid the garden of pests we mostly eradicate beneficial insects, with the additional side effect killing some song birds, frogs and other beneficial native fauna. The result is an amplification of an already existing imbalance that affects the overall health of the garden.
Why insects should be protected
Most insects are so tiny and mobile that most people never even realize that they exist. Take some time one afternoon to sit quietly in your garden and watch your plants, you will be amazed at the amount of life that exists there! Appreciating all of the life in your garden is part of being an organic gardener and a friend of the earth.
Slowing down and observing your garden you may think about Edward O. Wilson’s description of insects as “the little things that run the world.” Certainly, as far as the garden goes, this is true. A healthy, productive garden depends on a diversity of insects: pollinators such as the bumblebee, solitary bee species, butterflies and hawk moths; beneficial insect predators such as hoverflies, lacewings, parasitic wasps and ladybugs; and the pests themselves, such as aphids.
Birds are another great form of natural pest control. Birds and bats live off of bugs. It is ironic that pesticides often end up killing or harming local birds. Plant your garden near tall trees. Birds will establish nests in the trees and visit your garden to eat pesky beetles, moths and flies.
The nature of biodiversity
The truth is we need greater local biodiversity. The more insects and other fauna in our garden, the less likelihood the pests have of surviving. If you are having a problem with pests in your garden, you probably have an imbalance of fauna or an imbalance of soil nutrients.
In un-touched nature, pests and plant diseases do exist, but rarely get out of hand. This is because there is a natural system of checks and balances, which keep these things under control. Of course, your garden is not “untouched nature”- it is quite touched. You have planted plants here, which are not naturally occurring, you weed and dig and manipulate the earth and you will likewise have to encourage a balance in natural diversity. Encourage beneficial insects to visit your garden.
Many beneficial insects are vagabonds which are always in search of prey. Flowers will attract beneficial insects to your garden, nourish them, and induce them to search your garden for pest insects. Planting flowers will increase the likelihood that beneficial insects will colonize your garden and lay many eggs on your garden plants. After hatching, their young will crawl around the garden plants and feed upon pest insects such as aphids, caterpillars, leaf beetle larva, thrips, spider mites and whiteflies.
Next week we’ll talk about steps you can take increase the beneficial insect population in your garden.
