EUURA OLIGOSPILA GROUP

Euura frenalis - Bridled Willow Nematine

Nematus frenalis Thomson, 1888
Pteronus fastuosus Konow, 1904
Nematus (Pteronidea) fastosus var. ponojense Hellén, 1948
Nematus (Pteronidea) fastosus var. punctiscuta Hellén, 1948

Scattered records north to northern Scotland. Benson (1958) listed a single record from 1934. Thereafter, there were no further records until a run of a dozen between 1997 and 2021. The species seems to be local but potentially overlooked amongst other species (Musgrove, 2024).

Green in life but a very variable species. In the female the postocellar area, the scutellum, the mesosternum and more or less top of the abdomen are often marked with black. In the male there is a spot on the front and back of the head and the thorax, and the top of the abdomen are marked with black. The clypeus, orbits, rear corners of the pronotum, tegulae, and more or less the coxae and trochanters are whitish. Underside of the abdomen and legs are light brown. The antennae are light brown and darker dorsally.

Euura frenalis larvae feed on willows.

Jump to other species in the oligospila group

Size: Female: 5.0 - 6.5mm, male: 4.5 - 5.0mm.

GB IUCN status: Near Threatened
GB rarity status: Nationally Scarce

Distribution: England, Scotland, Wales, Ireland

Flight period: May to June

Plant associations: Salix spp. (willows).

The National Biodiversity Network records are shown on the map below. (See terms and conditions)

References:

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

Muche, W.H., 1974. Die Nematinengattungen Pristiphora Latreille, Pachynematus Konow und Nematus Panzer (Hym., Temthredinidae). Deutsche Entomologische Zeitschrift, 21(1/3), pp.1-137.

Musgrove, A.J. 2024. A review of the status of sawflies of Great Britain - Phase 3: The Tenthredinidae (subfamily Nematinae). Natural England, unpublished

Prous, M., Liston, A., Kramp, K., Savina, H., Vårdal, H. and Taeger, A., 2019. The West Palaearctic genera of Nematinae (Hymenoptera, Tenthredinidae). ZooKeys, 875, p.63-127

Prous, M., Liston, A., Mutanen, M. 2021. Revision of the West Palaearctic Euura bergmanni and oligospila groups (Hymenoptera, Tenthredinidae. Journal of Hymenoptera Research. http://zoobank.org/1459B177-AF2B-4D39-9483-E8BA21E70E67