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.
Size: 5 - 6mm
Distribution: Scotland, Ireland
Flight period: Univoltine, May to June
Plant associations: Juniperus spp. (junipers)
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
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
Ooststroom, S. J. van 1974: De Jeneverbes bladwesp, Monoctenus juniperi L., (Hym., Diprionidae). - Natura, Amsterdam 71(4): 58-61