Length 9 to 11 mm. A fairly large shieldbug, the two Eurygaster species are often known as Tortoise Bugs. The ground colour and intensity of the markings are variable. In adult E. maura the second antennal segment is approximately twice as long as third, whereas in adult E. testudinaria the second antennal segment is less than twice as long as third segment; genital examination is necessary to differentiate this species from E. maura - if this has not been done, please record as Eurygaster (cf) testudinaria (meaning 'likely to be'). 

Eurygaster maura is very similar and can only be reliably separated from E. testudinaria by genital examination. 

Determination of this species requires genital examination.

Dry and damp grasslands.

Adult: All year.

Nymphs feed on grasses between May and August, becoming adult from June.

Previously uncommon, it is now widespread in southern Britain and Ireland in and is expanding its range northwards.

True status in in Leicestershire and Rutland is not known at present and has been clouded by difficulty of identification.

https://www.britishbugs.org.uk/heteroptera/Scutellerideae/e_testudinaria.html