Cytisogaster genistae (Benson, 1947)

Cytisogaster genistae

One of three small species formerly included in the Rhogogaster picta group. All three have bicolorous blue-green/black stigma. This species is likely parthenogenic without any males or males undistinguishable from other species. The hind tibia are lined with black on the anterio-dorsal face. Facial markings and saw teeth are diagnostic (see Benson).
Larvae feed on broom and dyer's greenweed.

Size: 6 - 8.5mm

Status: Common

Distribution: England, Scotland, Wales

Flight period: May to July

Plant associations: Cytisus scoparius (broom), Genista tinctoria (dyer's greenweed)

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