Nematus septentrionalis

Alternative names
Craesus septentrionalis

The head, thorax and upper body of the adult sawfly is black, the lower half of the body is reddish brown. The legs are distinctive being broader nearer to the feet than above.

Identification difficulty

Adult, Larva and leafmine (when the host plant is identified)


Usually seen as larvae feeding on the leaves various deciduous trees

When to see it

Adults can be seen during the summer months.

Life History

The larvae are usually seen feeding in groups from late August to October and have a black head with a yellow collar. The body is a greyish green with rows of quite large, circular black spots running the length of the body.

UK Status

Fairly frequent in England, most records coming from the south.

VC55 Status

Fairly common in Leicestershire and Rutland.

Leicestershire & Rutland Map


Yellow squares = NBN records (all known data)
Coloured circles = NatureSpot records: 2020+ | 2015-2019 | pre-2015

UK Map

Species profile

Species group:
Records on NatureSpot:
First record:
25/09/2008 (Calow, Graham)
Last record:
28/06/2024 (Calow, Graham)

Total records by month

% of records within its species group

10km squares with records

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