Euura krausi - Kraus' Aspen Nematine

Two species have previously been confused under the name Amauronematus puniceus. Benson gives puniceus as feeding on aspen. This equates to Euura krausi. The other Salix feeding species is now called Euura punicea which is not currently recorded from Britain or Ireland. The females are yellow-brown to red-brown with black markings on a spot that encloses the ocellae extending to antennal bases, the bases of the mandibles and large areas of the back of the head. The antennae are black. On the thorax the propleura and mesosternum are mostly black and there are three broad stripes on the mesoscutum with the two outer ones converging towards the scutellum. The mesepimeron, metapleuron and dorsum of the metathorax are partially black on the sutures. The scutellum is yellow-brown with a narrow, dark front edge. The abdomen is extensively darked though this reduces to smaller dorsal black marks on the apical few tergites or even completely pale apically. The sawsheath is darkened apically. The head and thorax are densely and finely sculptured with a silky sheen. The tarsal claws are bifid. The saw is a valid characteristic for identification.

The males are significantly darker than the female with yellow on the clypeus, labrum, base of the mandibles base, malar space and to some degree lightened on the outer orbits.

Euura krausi larvae are green and feed on aspen.

Size: 5.5 - 7.5mm

Status: Data deficient

Distribution: England

Flight period: April to May

Plant associations: Populus tremula (aspen)


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.

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

Taeger, A. and Blank, S.M., 1998. Beitrag zur Kenntnis einiger Nematinae (Hymenoptera: Tenthredinidae). Pflanzenwespen Deutschlands (Hymenoptera, Symphyta). Kommentierte Bestandsaufnahme. Goecke & Evers, Keltern, pp.247-277