Dolerus junci (Stephens, 1835) - Black-tailed Weeper
=Dolerus cothurnatus sensu Benson

Recorded widely across all of mainland Britain (Musgrove, 2023).

Abdomen red with dark apex. At least the front legs with some red about the knees. Mesopleura with crater-like punctures in the middle. Entire mesonotum black. Female 8-9mm. Male 7-8mm.

Dolerus junci  larvae feed on water and marsh horsetail. 

Jump to other Dolerus species

GB IUCN Status: Least Concern
GB Rarity Status: None

Distribution: England, Scotland, Wales, Ireland

Flight period: May to July

Plant associations: Equisitum fluviatile and palustre (water horsetail and marsh horsetail)


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.

Liston, A., Mutanen, M., Heidemaa, M., Blank, S.M., Kiljunen, N., Taeger, A., Viitasaari, M., Vikberg, V., Wutke, S. and Prous, M., 2022. Taxonomy and nomenclature of some Fennoscandian Sawflies, with descriptions of two new species (Hymenoptera, Symphyta). Deutsche Entomologische Zeitschrift, 69(2), pp.151-218.

Musgrove, A.J. 2023. A review of the status of sawflies of Great Britain - Phase 2: The Athaliidae and the Tenthredinidae (excluding Nematinae). Natural England, unpublished