10 mm or more. An all-black sawfly, similar to others in the Dolerus genus so detailed examination is needed for a secure identification. Females have a sawsheath which narrows to a point and with setae (when viewed from above) which are largely straight. Tergites are dull due to surface sculpture and tergite 1 is punctured throughout. Males have tergite 8 with a wide triangular, unpunctured area which is glabrous and occupies around one third of the apical margin.

Other Dolerus species.

Unless identified by a recognised expert, photographic evidence is required and the specimen should be examined with a microscope. In the comments box, state the key or ID method used. Note the size and describe the identifying characters.

Various habitats including grassland and hedgerows.

May to July.

Whilst the larvae are associated with several grasses, the adults are nectar feeders visiting flowers such as umbellifers.

Widespread in the southern half of Britain.

Most probably common but under-recorded in Leicestershire and Rutland.

https://www.sawflies.org.uk/dolerus-poodolerus-niger/