Nematus umbratus Thomson, 1872

Nematus umbratus

This species is similar to leucotrochus, but differs in the following features. The costa in the fore wing is pale at least in the basal two-thirds and the antennae are always completely black. On the mesonotum, the edges are often yellow and the abdomen is mostly all yellow. In the male, the upper side of the abdomen is yellow with a black stripe (completely black in leucotrochus, except for the ninth tergite).

Larvae feed on birches, elms, hazel and alders.

 

Size: Female: 5.5 - 7.5mm, male: <6.5mm.

Status: Rare

Distribution: England, Scotland, Ireland

Flight period: May to June, July to September

Plant associations: Betula spp., Ulmus spp., Corylus spp. and Alnus spp. (birches, elms, hazel and 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

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

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