These wasps are black with yellow spots. They have a narrow waist (pedicel) about the same length as the rest of the abdomen. They range in total length from 24 to 28 mm.
These insects owe their name to the short golden hairs that cover the thorax and head.
They have black antennae and orange or golden brown wings. The legs are orange, except for the coxa, the part nearest the body, which is black. Great golden digger wasps have a narrow waist and a bi-coloured abdomen: orange-red in front and black behind. Their total length is 15 to 27 mm, and males are slightly smaller than females.
These insects come in widely varying sizes (10 to 55 mm long), but all have an elongated abdomen attached to the thorax by a characteristic “thread-waisted” long, narrow, petiole-shaped structure. They may be entirely black or brown or dark with white, yellow or red markings. The females’ forelegs often have specialized structures for digging.
The larvae are pale coloured and legless.
In the past, the Sphecid family included the Crabronidae [lien], a fairly similar-looking group of wasps that now forms a separate family.