Ancistrocerus trifasciatus



Conservation status

Not Assessed

Species Biology


  • Body length: 7-12mm, males smaller than females
  • Primarily black body with three (sometimes four) yellow bands on the abdomen
  • Legs yellow and black
  • First yellow band on the abdomen expanded at the sides in females
  • Could be confused with Symmorphus bifasciatus or other Ancistrocerus species. The medium build, yellow and black legs and three abdominal bands can help with identification but ideally a microscope and specialist keys are needed.


Not well known in Ireland, but it has been recorded from partially wooded areas, gardens, parks and damp scrub and wet grassland. Apparently more likely to be found in damper areas than some of its relatives.

Flight period

June-September, peaking in June and July.

Nesting biology

In Ireland it has been observed nesting above ground in bored timber and bee hotels. It has also been reported using old plant stems, disused galls and holes in masonry. The nesting holes are divided into cells, each one with several small moth caterpillars and a single egg laid by the female wasp.  These are usually several centimeters deep and capped with soft mud. The larvae hatch and consume the caterpillars before pupating and emerging the following year. 

Flowers visited

Not an avid nectar feeder, but will occasionally visit Bramble (Rubus sp.), Hogweed (Heracleum sphondylium) or Thistles (Cirsium sp). 

Native region

Europe, Temperate Asia

Similar species

  • Symmorphus bifasciatus
  • Other Ancistrocerus species (see above)


World distribution(GBIF)

Temporal change

Records submitted to Data Centre in 2022

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How can you help

This species has been under-recorded in Ireland. Surveying suitable habitats and sending in records of this species would be greatly appreciated.



Stelfox, A. W. (1924). A List of the Hymenoptera Aculeata (Sensu Lato) of Ireland. Proceedings of the Royal Irish Academy. Section B: Biological, Geological, and Chemical Science37, 201–vi.