Nematinus steini - Stein's Alder-cutter

North to northern Scotland. Seemingly common and widespread, although assessment is clouded by unhelpful nomenclatural issues. Records assigned to Benson's "Nematinus luteus" refer to what we now know to be steini and records assigned to willigkiae refer to luteus (Musgrove, 2024).

An almost entirely orange-yellow species.

In the female, the sawsheath is broad, parallel sided and slightly indented at the apex. The thorax may be flecked with black, as may be the post-scutellum, the mesosternum and the basal tergite. The subcostal, marginal and anal veins are dark basally becoming yellow towards the apical half of the wing.

In the male, yellow are the costa, clypeus, tegula, edge of pronotum and the mesopleura.

Larvae feed on alders and pupate in the ground.

Jump to other species of Nematinus

Size: Females: 6 - 8.5mm. Males: 5 - 6.5mm.

GB IUCN status: Least Concern
GB rarity status: None

Distribution: England, Scotland, Wales, Ireland

Flight period: June to August

Plant associations: Alnus spp. (alders)

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

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 Natural England, unpublished