Wall Mason Wasp

Ancistrocerus parietum


Over all length 7 to 12mm. There are nine very similar wasps in this genus. A. parietum is best distinguished from the others by a notch in the front of the first segment of the abdomen, which none of the others possess.


A wide range of habitats are used, including gardens, river banks, parks and woods. The female nests in hollow bramble or elder branches, tubular holes in walls where she deposits larvae of moths and butterflies to feed her young.

Status and distribution

Widespread but thinly recorded in England, but less common in the West Country, Wales and Scotland. Thinly recorded in Nottinghamshire and recorded once at Netherfield Lagoons.

Best time to see

June and July.