Arge

The Argidae are the second largest family of sawflies globally. They are stockily-built, slow flying insects characterised by having the flagellal segments of the antennae fused into a single filament. In males the flagellum either has a brush of setae on the underside, or is shaped like a tuning fork.

The genus Arge is distinguished from other genera within the family by having an enclosed apical cell in both the fore and hindwing and the hind tibia has a pre-apical spine. In the males, the antennae are simple. There are over 250 species of Arge globally and they are the dominant genus in tropical regions of Africa. There are 13 species in Britain and seven in Ireland. Arge metallica is present in Ireland but not known from Britain. Adults will often visit umbellifer flowers. The larvae are free feeding on Rosaceae, Salix, Betula and Quercus species.

Key to the Arge species of Britain and Ireland

Species list:

Orange abdomen species

Arge cyanocrocea (Forster, 1771)

Arge melanochra (Gmelin, 1790)

Arge ochropus (Gmelin, 1790)

Arge pagana (Panzer, 1797)

Black abdomen species

Arge berberidis Schrank, 1802

Arge ciliaris (Linnaeus, 1767)

Arge enodis (Linnaeus, 1767)

Arge expansa (Klug, 1834)

Arge fuscipes (Fallén, 1808)

Arge gracilicornis (Klug, 1814)

Arge metallica (Klug, 1834)

Arge nigripes (Retzius, 1783)

Arge rustica (Linnaeus, 1758)

Arge ustulata (Linnaeus, 1758)

References:

Benson, R. B. 1939: On a new and some little known European species of Arge Schr. (Hymenoptera Symphyta). - (The) Proceedings of the Royal Entomological Society of London. Series B: Taxonomy, London 6: 114-117

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. D. 1992: Taxonomy of European Arge related to nigripes (Retzius) (Hymenoptera, Symphyta: Argidae). - Entomologische Berichte Luzern, Luzern 27: 135-140

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