Although a common insect the common green shieldbug (Palomena prasina) is not often seen. This is a species hidden deep in garden shrubs, hedgerows and woodland where, in summer, its colouring and relatively small size gives it protection from its many predators.
At first glance you can see immediately why this and its related species are called shieldbugs. Their general shape, formed by its wing cases, is the form of a classic heraldic shield. They are part of the order hemiptera which is the scientific name for bugs and so shieldbug seems the obvious name for them.
The common green shield bug is a bright green with a darker triangular patch to the rear. On close inspection you can see that the wing cases have tiny holes in them. Later in the summer the insect turns a darker colour becoming almost brown before it hibernates for the winter. This change of colour helps it adapt to its surroundings during the winter whilst asleep and so helps to disguise its presence.