Athalia

Athalia

This genus of small black and orange sawflies is restricted to Eurasia and Africa. In Britain and Ireland there are a total of 9 species, though there is some evidence to suggest that Athalia circularis is a species complex. Athalia cordata is probably the most common. There are further species on the near continent that may be present undetected in Britain and Ireland. Athalia rosae are known to migrate from the continent and significantly boost the local population.

The antennae are 10 to 12 segmented. The clypeus is subtruncate apically or slightly rounded. The hind wing has two medial cells. The mesopleural suture is sinuate.

The Athalia tend to be multivoltine meaning that numbers can build rapidly in a season. Some species can therefore become a pest of agricultural crops, primarily brassicas (mustard, turnips, etc). Different species will often congregate and fly together it is therefore possible to catch several species in one sweep of the net.

Larvae are generally gregarious and their ground colour is bluish black or grey, some with obvious warts. Athalia rosae has historically been a pest of turnips, mustard and radish, etc. Athalia lugens can be a pest of similar crops though seemingly not in Britain.

Cheat sheet to the Athalia of Britain and Ireland

Species list:

Athalia ancilla Serville, 1823

Athalia bicolor Serville, 1823

Athalia circularis (Klug, 1815)

Athalia cordata Serville, 1823

Athalia cornubiae Benson, 1931

Athalia liberta (Klug, 1815)

Athalia lugens (Klug, 1815)

Athalia rosae (Linnaeus, 1758)

Athalia scutellariae Cameron, 1880

References:

Benson, R. B. 1931: Notes on the habits and the occurrence of Athalia species in Britain. - The Entomologist's Monthly Magazine, Third Series, London 67(17): 134-137

Benson, R. B. 1932: Sawfly Notes. - II. Parallel Variation in Athalia lugens Kl. and Athalia cordata Lep. (Hymenoptera Symphyta). - The Annals and Magazine of Natural History, including Zoology, Botany, and Geology; Tenth Series, London 9: 183-188

Benson, R. B. 1932: Sawfly Notes. - III. On some Species of Athalia from Central Asia and from the Mount Everest Region (Hymenoptera Symphyta). - The Annals and Magazine of Natural History, including Zoology, Botany, and Geology; Tenth Series, London 9: 5

Benson, R. B. 1946: A mass-movement of the sawfly Athalia cordata Lep. in North Devonshire (Hym., Tenthredinidae). - The Entomologist's Monthly Magazine, Fourth Series, London 82(7): 87

Benson, R.B., 1952. Handbooks for the Identification of British Insects. Hymenoptera, Symphyta, Vol 6, Section 2(a-c), Royal Entomological Society, London

Benson, R. B. 1962: A revision of the Athaliini (Hymenoptera: Symphyta). - Bulletin of the British Museum (Natural History). Entomology series, London 11: 333-382

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