A follow up sighting to 4223722 showing one of the Sawfly larva going through the process of moulting. In the first image the external skin being shed can be seen splitting along the legs. The larva was observed repeatedly throwing the top half of its body backwards and gradually exiting the old skin.
In lieu of a comprehensive study or guide to the larvae of the nearly 60 species in subfamily Perginae; subfamily level identification is the only valid option.