EVERYONE loves a bit of help in the garden, and some of the best helpers are happy to work all day, every day, for nothing.
They’re called insects and beneficial insects will devote their entire lives to managing pests and diseases in your garden, if you let them.
Much of the pollinating work in the food garden is performed by insects, most notably bees, hoverflies, and butterflies.
So it’s important to provide nectar sources by planting flowers.
They fall into three broad groups – pollinators, predators and parasites.
Pollinators fertilise flowers, which increases the productivity of fruit and vegetable crops.
Predators consume pest insects as food. Parasites use pests as nurseries for their young.
Predators, such as lacewings, ladybugs and hoverflies feed on insect pests.
Some of the adults feed on pollen, nectar and honeydew, and some on insects.
All lay eggs that produce predatory larvae, which feed on aphids, thrips, mites, scale, mealy bugs and caterpillars.
Lacewing larvae, known as aphid lions and wolves, feed for 15-20 days, eating 100 plus insects a day.
Most ladybugs are predators with ravenous appetites for aphids and other soft-bodied insects.
Adult ladybugs will eat several hundred aphids before mating and laying eggs on aphid-infested plants.
The larvae feed on aphids as well. Some ladybug species prefer other pests, like mites, white flies, or scale insects.
A few even feed on fungus or mildew – you might see them feeding on cucumber or zucchini leaves if you have powdery mildew.
One small sub-family of ladybugs includes leaf-eating beetles.
Some beetles in this group are pests, but by far the majority of ladybugs are beneficial predators of pest insects.
Adult hover flies feed on pollen and nectar and are often mistaken for bees.
The female lays its white oval eggs amongst colonies of aphid or mites.
The eggs yield maggots which feed on aphids and other soft-bodied insects.
Parasites deposit eggs on or into the pest or its eggs.
The larva then hatches and ultimately consumes and kills the pest.
Parasites tend to be host-specific, that is, they will only attack a particular species of pest. Most parasites are either wasps or flies.
Parasitic wasps and flies are small, and don’t sting.
There are many species, and the adults usually feed on nectar and pollen.
If you want to get some of these bugs working for you, there are two things you need to do.
First, reduce or eliminate the use of pesticides in your garden.
Many sprays, including pyrethrum, will kill good bugs as well as bad ones, making pest control harder.
There are some safe, selective pest control products on the market, so do your research before reaching for the sprays.
Second, give the good bugs a reason to take up residence in your garden by providing food and shelter for them.
You can intersperse the insect-attracting plants in your veg patch, or place them in a separate, nearby area.
Flowers are a source of food for many pest-controlling insects, particularly in their adult form.
Many have short mouthparts, so simple open flowers or small flowers are best.
Among the favourites are flowers such as fennel, dill, Italian parsley, daisies, cosmos, zinnias, dandelions, marigolds, tansy, sunflowers, thistle, and yarrow.
Members of the cabbage family are good too – their simple flowers are full of nectar and pollen.
Mustards and rocket work in the same way.
And they’ll also bring in beneficial insects like lacewings and hoverflies which are really good at controlling aphids.
Here’s an example. Lacewing larvae will consume vast numbers of aphids, so you can plant tansy, fennel, dill and Italian parsley to attract them the adults, which will in turn lay eggs producing the predatory larvae to feast on aphids.
Learn to recognise these good bugs, in all the stages of their lives.
Ladybug larvae don’t look much like ladybugs, so it would be easy to dismiss them as unimportant.
Be careful with pesticides, choosing products that are selective and won’t harm the good guys.
One of the beautiful things about this approach is that it helps us to appreciate the full life cycle of the plant, not just the period when we can eat it.
Instead of getting miserable when the coriander goes to seed, you can now delight in the fact that those pretty flowers will attract beneficial insects that will feed and breed, thus providing free, natural pest control for your garden.
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