As with all Tenthredopsis species Tenthredopsis friesei is variable in colour. The description given here follows Blank and Ritzau 1998 but it should be noted that British specimens may differ in colour from continental counterparts.
In the female the middle area of the second tergite is significantly smoother and glossier than the third. The eye orbits and vertex are black or only slightly pale. The pronotum is black as is most of the mesoscutum. The abdomen is black but broadly red on at least tergite three to six.
Males of this species can be distinguished by the penis valves which have needle-like projections that are shorter than the hind femur inner apical spur. Males also lack a peripheral vein on the hind wing. Females have a black abdomen with a red girdle.
Larvae feed on grasses.
Size: 10 - 11mm
Distribution: England, Scotland, Wales, Ireland
Flight period: May to July
Plant associations: Gramineae
The National Biodiversity Network records are shown on the map below. (See terms and conditions)
Benson, R.B., 1952. Handbooks for the Identification of British Insects. Hymenoptera, Symphyta, Vol 6, Section 2(a-c), Royal Entomological Society, London
Haris, A. and Gyurkovics, H. (2014) The genus Tenthredopsis Costa, 1859 in Hungary (Hymenoptera: Symphyta). Natura Somogyiensis, 24 pp. 99-124.
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