Dr Stephen Henning, a zoologist, started out explaining how many different animals already live in our gardens. He explained how food chains and food webs work, with plants as producers of food at the bottom of the chain, then animals eating the plants, and other animals eating those plant eaters. He showed how, once a balance is established in our gardens, we will find that most garden pests can be kept under control by their natural predators with no need for using artificial insecticides or herbicides.
It was interesting to find out that a blue tit chick will eat 100 caterpillars a day, and there may be as many as 16 chicks in a nest. So the parents of those chicks could be foraging for 1600 caterpillars in our gardens every single day! This should drastically reduce the damage done to our plants, if we can make sure birds are welcome and safe in our gardens.
We also heard about the benefits of wasps in the garden – many of them parasitise caterpillars which might otherwise cause problems in the garden. As many as 95% of butterfly and moth caterpillars are likely to be parasitised if wasps are left to do their work.
And we looked at the lacewings and ladybirds which prey on aphids – left to their own devices, they will help control these pests very effectively, but they will also be killed by any insecticide used on the aphids. Any artificial poison will knock the balance out.
Thrushes and hedgehogs eat slugs and snails – and so, occasionally, do wood mice! So we should be encouraging all these animals into our garden to help keep everything in balance.
Stephen emphasised the importance of having a pond or bucket of water with access for small animals in our gardens, of having as much indigenous planting as possible with some wilder areas left to grow freely, and of aiming to grow single, rather than double varieties of flowers, as these are much more useful for insects which are so important in the ecology of our gardens.
We were given the chance to make our own small insect hotels out of flowerpots, pinecones, sticks and other plant matter. If we have plenty of habitats in our garden, the diversity of wildlife will increase.