Monoctenus juniperi

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

Status: Rare

Distribution: Scotland, Ireland

Flight period: Univoltine, May to June

Plant associations: Juniperus spp. (junipers)


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.

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