Rhadinoceraea micans - Iris Sawfly
Benson (1952) considered this a rather local species north to Cheshire. It is now known to occur widely throughout England and Wales north to Durham, and can be fairly easy to detect (including as a larva), hence something of a range expansion seems to have occurred (Musgrove, 2023).
An entirely black species often seen flying around the host plant. Very similar to Phymatocera aterrima which feeds on Solomon's seal. In Rhadinoceraea micans the antennae are about twice as long as the width of the head and about as long as the abdomen. In aterrima the antennae are at least three times as long as the width of the head and as long as the whole body.
The larvae feed on water-loving irises.
Size: 7 - 8mm
GB IUCN Status: Least Concern
GB Rarity Status: None
Distribution: England, Wales
Flight period: April to June
Plant associations: Iris pseudacorus. (flag iris, and other water-loving irises)
Benson, R.B., 1952. Handbooks for the Identification of British Insects. Hymenoptera, Symphyta, Vol 6, Section 2(a-c), Royal Entomological Society, London
Liston A, Knight G, Sheppard D, Broad G, Livermore L (2014) Checklist of British and Irish Hymenoptera - Sawflies, ‘Symphyta’. Biodiversity Data Journal 2: e1168. https://doi.org/10.3897/BDJ.2.e1168
Musgrove, A.J. 2023. A review of the status of sawflies of Great Britain - Phase 2: The Athaliidae and the Tenthredinidae (excluding Nematinae). Natural England, unpublished