Fairly large shieldbugs, the two Eurygaster species are often known as Tortoise Bugs. The ground colour and intensity of the markings are variable. This species is distinguished from the slightly smaller and rarer E. maura
by the slight central depression at the front of the head and the slightly more protruding hind corners (‘shoulders’) of the pronotum. These characters are not always reliable; genitalic examination may be necessary. Females show a gap between the genital plate and the previous segment (often visible in the field with a hand lens), while the male aedaegus has 4 internal spines (requires dissection).
Nymphs feed on grasses between May-August, becoming adult from July. Previously uncommon, it is now widespread in southern Britain and Ireland in dry and damp grasslands and is expanding its range northwards.
Adult: All year
Length 9-11 mm… British Bugs