Poke about among the leaves and stems of your plants and you will discover an exciting world home to hundreds of species. These invertebrates are incredibly varied but can be divided into one of four primary functional groups based on what they eat;
Examples: caterpillars and beetles (chewing mouthparts), thrips, aphids and other true bugs (sucking mouthparts)
Food chain function: eat living plants. The group contains generalists which are able to feed on a wide range of plants and some very specialist feeders which only feed on a few plant species. They sometimes damage garden plants
Examples: predatory beetles (e.g. ladybirds), true bugs, spiders and parasitoid wasps
Food chain function: eat other animals. They are vital in any healthy ecosystem and help keep some problematic invertebrates in check, including many herbivores
Examples: the harvestman (relative of the spider) and common earwig (feeds on other insects, such as aphids, as well as the leaves of some plants)
Food chain function: eat both plants and animals. This broad feeding strategy makes them very adaptable if one food source becomes scarce
Examples: springtails, woodlice and some beetles that feed exclusively on dead material
Food chain function: eat decomposing organic matter, of animal or plant origin. They are vital in recycling dead material in the garden. Many also feed on fungal and algal growths
Why are these invertebrates important?
While some of these animals are traditionally regarded as pests by gardeners, they support populations of natural predators, which in turn help maintain a balance of invertebrates in general. They break down dead plant material and recycle nutrients. They also provide food for garden birds and mammals such as hedgehogs. In short, an abundance of bugs of all types equates to a healthy garden ecology.
Does a plant's origin affect how well it supports these invertebrates?
In the context of garden plants, it would appear plant origin does have a bearing. However, other factors such as vegetation density also play an important role. Below are the findings and recommendations to gardeners from recent research.