The adult sawfly 5-6 mm and mainly all-black. The hind tibia are generally black but on the outer side of the base it may be considered dark rather than black. The head has deep supra-antennal grooves. The antennal pedicel is as broad as, or broader than, it is long. The tarsal claws have a basal lobe and are bifid with the inner and outer tooth close together.

Larvae have branched spines.

Larvae feed on Meadowsweet, avens and Bramble.

Adults emerge in spring.

Larvae feed mainly on Raspberry but will also feed on the leaves of species such as Geum and Filipendula as well as other Rubus species.

Exact status in Britain is difficult to determine due to lack of records, but it seems to be fairly widespread.

Status in Leicestershire and Rutland not known.

https://www.sawflies.org.uk/monophadnoides-rubi/