Steel Blue Saw Fly

This is a wasp in fact and is called "steel blue" because of the steel-blue colour of the larvae. It is hefty-looking because of its built-up thorax on the dorsal side which is a rich dark chocolate colour and has a creamy white patch. The long wings cross over the body completely covering it.
The lower part of the legs are also a pale colour.
The wasp is about 24mm in length.