Monoctenus juniperi - Juniper Combhorn

Seemingly widespread in the Scottish Highlands but no records yet from the more southerly Juniper stands (Musgrove, 2022).

This is the only Diprionidae species in Britain and Ireland where the anal vein of the forewing is divided into two cells by vein 1A and 2A being fused rather than connected by a short cross-vein. In the males, the antennal flagellae have comb-like protruberances on one face only, rather than the double comb of other Diprionidae males. The head and thorax are mainly black. The female has lateral yellow marks each side of the abdomen and is mostly yellow ventrally. The stigma is pale with dark margins and the tibia and tarsi are pale.

Monoctenus juniperi larvae feed on junipers.

Jump to other Diprionidae genera and species

Size: 5 - 6mm

GB IUCN Status: Least Concern
GB Rarity Status: Nationally Scarce

Distribution: Scotland, Ireland

Flight period: Univoltine, May to June

Plant associations: Juniperus communis (Juniper).

The National Biodiversity Network records are shown on the map below. (See terms and conditions)

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

Musgrove, A.J. 2022. A review of the status of sawflies of Great Britain - Phase 1: families other than Tenthredinidae. Natural England, unpublished

Ooststroom, S. J. van 1974: De Jeneverbes bladwesp, Monoctenus juniperi L., (Hym., Diprionidae). - Natura, Amsterdam 71(4): 58-61