The small invertebrates with the big job of maintaining the ecological balance
Here I am focusing on some of the smaller creatures that are often overlooked in our gardens and green spaces. Even a small garden (unless it is covered in paving or gravel) will usually be home to a wide range of fascinating invertebrates, many of which are essential for maintaining the ecological balance of these important habitats.
It is easy to dismiss them as ‘pests’, though in reality few seriously damage garden plants. Aphids can certainly be a problem at times, as can snails and slugs in wet weather, while wasps can be a nuisance to people, especially in barbecue season. Most however are of positive benefit, or at least neutral in their effect, all are fascinating, and many are beautiful. A garden with a variety of micro-habitats can support a huge range of ‘mini-beasts’ that are well worth getting to know.
It is often children who are most interested in garden wildlife and they tend to observe even the smallest creatures without prejudice, thus allowing pure observation, uncluttered by negative associations. Our four-year-old grandson for example takes great pleasure in searching under logs and stones for snails, slugs and woodlice and is immensely proud that he knows that insects have six legs, spiders have eight, and woodlice fourteen!
One of our larger true bugs is the forest shieldbug (Pentatoma rufipes). It is quite common in gardens and feeds on the sap of a range of trees. The bright yellow spot in the centre of its back is distinctive.
There are plenty of moths about, and they have been especially active during the warm dry nights we experienced earlier this month. Only about 60 species of butterfly occur regularly in the UK, but we have more than 2,500 kinds of moth. Local naturalist and photographer Jon Heath has seen more than 500 species of moth in his Cambridge garden and has kindly provided some of the images for this article. Jon catches the moths in a garden light trap, photographs them, and then releases them unharmed the next night.
One of the most remarkable of common moths is the strange buff-tip (Phalera bucephala) which has taken camouflage to the extreme, resembling when at rest the broken twig of a tree. Another common species found in gardens is the stunning creamy-white swallow-tailed moth (Ourapteryx sambucaria) whose hind wings sport short, pointed tails.
Hoverflies have also been much in evidence during the warm, dry weather, and two of the larger species are the great pied hoverfly (Volucella pellucens) and the hornet hoverfly (Volucella zonaria). The former likes to feed on bramble flowers in shady, wooded areas, and is quite common in summer, while the latter has increased over recent years and will sometimes visit flowers in the garden. Both are boldly marked, the hornet hoverfly gaining safety from avian attack through its superficial resemblance to that large wasp. The larvae of both these species live in the nests of common and German wasps.
Speaking of wasps, I recently found a robin’s pincushion on one of our roses. This curious object is produced by a species of gall wasp. The wasp lays her eggs in the developing leaf bud, and chemical distortion causes a feathery gall to grow instead of a normal leaf. The tough woody chamber inside is home to about 60 wasp grubs that develop there and emerge the following spring. The gall causes no further harm to the rose plant and has a distinctive beauty of its own.
To see more of Jon’s wildlife photographs check out his Twitter feed at https://twitter.com/Jon_Heath_