The species of shieldbugs & allies found in the UK
Shieldbugs are a common name we give to true bugs whose shape does remind one of the shields, knights used to defend themselves with in medieval times.
Scientifically however, whilst all belonging to the Superfamily Pentatomoidea, there are members of several different families.
First of all we have the true shieldbugs (Pentatomidae). They can be told apart from the other families by their large scutellum or shield, the triangular shield immediately behind the thorax shield. The Acanthosomatidae is the second family. Having no common English names the members of this family usually are also referred to as shield bugs. Bigger species certainly do look like shield bugs, but many smaller species do not. The burrowing bugs, also called burrower bugs (Cydnidae), shield-backed bugs (Scutelleridae) and ebony bugs (Thyreocoridae).– historically called (Corimelaenidae) – are also in part called shield bugs, but both families are much smaller than the previous ones.
There are also many members of the squash bugs and leaf footed bugs (family Coreidae) which really do look like the shield bugs.
In Britain several species are at or close to the northern edge of their range and most have a southerly distribution. Just 12 of the 69 British species are found in Scotland. Whilst some seem to be in decline in certain areas, others have increased their range. As recently as 2003, another species of shield bug, the southern green shield bug (Nezara viridula) was found breeding for the first time in the London area. This is the latest arrival from elsewhere in Europe.
The larval forms are like miniature versions of the adult but may have a different colour pattern and are without wings. They pass through five nymphal instars before moulting into fully winged adults.
We illustrate here the adult bugs unless stated otherwise.