Old observation. Found on the rocks right on the waters edge. Really unusually colouring. The Landcare Hymenoptera key isn't working for me, so help with this one much appreciated https://resources.landcareresearch.co.nz/InteractiveKeys/family_key/Key/Guide%20to%20the%20Family%20Level%20Identification%20of%20Hymenoptera%20in%20New%20Zealand.html