This colorfull shieldbug had entered the house and was roaming about the hallway. It is a Brassica shieldbug (Eurydema oleracea) [1,2], a species that I had not seen before: a new garden species!
The shieldbug can be found in two color scheme variants: black and white, or black and red .
References1 Nederlands Soortenregister
2 Aukema, B., Th. Heijerman & V.J. Kalkman 2016. Veldgids wantsen deel 1. – EIS Kennis centrum Insecten, Leiden.