Nematinus steini Blank, 1998

Nematinus steini

[NB. This species is given as luteus in Benson's key.]
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.
In both sexes there are hairs on the lower part of the mesopleura above the sterno-pleural line. These hairs are absent in the English, Welsh and Irish form of the similar luteus but present in the Scottish form of luteus.
Larvae feed on alders and pupate in the ground.

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

Status: Common

Distribution: England, Scotland, Wales, Ireland

Flight period: June to August

Plant associations: Alnus spp. (alders)

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