The Delta Petiolata Potter Wasp is quite large at around 20 to 30mm, although males are smaller and thinner. It is marked with yellow, brown and black. The yellow colouring forms a distinctive pattern on the thorax.
Despite its menacing appearance, it is totally harmless and has a surprisingly mild sting, and will generally not attack.

Delta Petiolata Potter Wasp

Delta Petiolata Potter Wasp