Rambur's Pied Shieldbug (Tritomegas sexmaculatus) closely resembles the Pied Shieldbug (Tritomegas bicolor).
However, Rambur's Pied Shieldbug has a completely dark (black) membrane while the Pied Shieldbug has a brownish or translucent wing membrane.
In addition, Rambur's Pied Shieldbug features more extensively white side-margins on its 'shoulders' (pronotum) compared to the Pied Shieldbug.

Hortobágy-Halastó, Hortobágy National Park, Hungary, 2 May 2019