Wheat Stem Borer - Cephus pygmeus

Description

5-10mm. The commonest of the three Cephus species, often found visiting yellow flowers such as dandelions and buttercups. The abdomen is long and thin - black with narrow yellow bands. The wings are clear with a dark stigma. In females, the hind tibia is mainly dark, possibly with yellow just on one side.

Similar Species

Cephus spinipes is very similar but has bifid claws where the inner tooth is more perpendicular and not in line with the terminal tooth. Females have a yellow hind tibia with black just at the apex.

Identification difficulty
ID checklist (your specimen should have all of these features)
  • More swollen antennal club (pre-apical segments broader than long)
  • Hind tibia with darker markings on inner side at apex or over all of tibia
  • Sawsheath protrudes inline with body profile when viewed side-on
  • Claws bifid at the apex – the teeth being more or less parallel
Recording advice

Microscopic examination is necessary. Please comment how you reached an ID.

Habitat

Around fields where wheat is grown.

When to see it

Peak is June and July.

Life History

The larvae bore into the stems of wheat and a few other cereals and grasses.

UK Status

Widespread and thought to be fairly frequent in England and Wales.

VC55 Status

Status in Leicestershire and Rutland not known.

Leicestershire & Rutland Map

MAP KEY:

Yellow squares = NBN records (all known data)
Coloured circles = NatureSpot records: 2025+ | 2020-2024 | pre-2020

UK Map

Species profile

Common names
Wheat Stem Borer
Species group:
Sawflies
Kingdom:
Animalia
Order:
Hymenoptera
Family:
Cephidae
Records on NatureSpot:
28
First record:
06/06/2013 (Calow, Graham)
Last record:
21/06/2024 (Dejardin, Andrew)

Total records by month

% of records within its species group

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