EUURA MYOSOTIDIS GROUP

Euura leionota - Smoothback Birch Nematine

Pteronidea leionota Benson, 1933
Nematus amaurus Vikberg, 1982
Nematus nigritus (Lindqvist, 1958)
Nematus clavicercus Lindqvist, 1957
Nematus leionotus (Benson, 1933)
Pteronidea microserrata Lindqvist, 1941
Nematus microserratus (Lindqvist, 1941)
Pteronidea verticalis Lindqvist, 1958
Nematus verticalis (Lindqvist, 1958)
Euura amaura (Vikberg, 1982)
Euura microserrata (Lindqvist, 1941)
Euura clavicercus (Lindqvist, 1958)
Euura verticalis (Lindqvist, 1958)

Scattered locations north to northern Scotland. Benson (1958) knew of four records. No more came to light until 1990, then a small number were found up to 2010 but none subsequently, which seems a surprising absence with no artefactual reason behind it. All have been females (where sex noted) (Musgrove, 2024).

This species is mainly yellow with reddish on the top of the head, the thorax and the abdomen. The following are marked with black: a spot on the base of the antennae, the two basal antennal segments and more or less the dorsal face of the antennae, an ocellar spot, the posterior corners of the pronotum, the longitudinal grooves on the mesoscutum and the sunken parts of the metanotum, the rear edge of the scutellum and the postscutellum, more or less the propleurae and the sternal and pleural parts of the thorax. The abdomen is also black on the first tergite and more or less the basal 4 to 6 tergites in the middle. Males are undescribed.

Euura leionota larvae feed on birches.

Size: Female: 7.0mm, male: 4.5 - 5.0mm.

GB IUCN status: Endangered
GB rarity status: Nationally Scarce

Distribution: England, Scotland, Ireland

Flight period: April to May

Plant associations: Betula spp. (birches).

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