---

Louis is right - both Eurygaster testudinaria and E. maura are very similar, and examining the genitalia is often the only way to separate them reliably. Checking up on their British distribution, it looks like testudinaria is the most likely species in Sussex, though maura does occur in neighbouring counties and is associated with drier grassland. Unless there are other recent records from Sussex, I guess it would be safer to go with testudinaria.