The head is shiny black; the body greenish brown, becoming darker with age.

[5][6] The adult iris sawflies lay their eggs in May on the leaves of irises (especially the yellow flag).

[7] The larvae are serious garden pests and can completely defoliate irises, especially the yellow iris, when these are growing by water.

[9] The iris sawfly is endemic to Europe, being found in Britain, France, Sweden, Finland, Denmark, Netherlands, Germany, Poland, Italy, Bulgaria and Romania.

It is absent from Spain, Sicily and the Mediterranean islands, Greece, former Yugoslavia and countries east of Poland.