A genus of slender, elongate sawflies. Ametastegia carpini has an entirely black thorax, abdomen and mostly dark hind legs though the hind trochanter is always pale apically. The scutellum is shining and impunctate in the middle. In the female the tegulae are usually white. In the male, the tegulae vary from yellowish-brown to black.
Larvae are free living and feed on hardy geraniums and crane's-bills.
Size: 6 - 8mm
Distribution: England, Scotland, Wales, Ireland
Flight period: bi- or multivoltine, May to June, July to August
Plant associations: Geranium spp. incl. robertianum, pratense, sanguineum, sylvaticum (crane's-bills)
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