EUURA PROXIMA GROUP

Euura proxima - Willow Bean-galler

Nematus proximus Serville, 1823
Pontania proxima (Serville, 1823)
Nematus gallicola Stephens, 1835
Nematus vallisnierii Hartig, 1837
Nematus festivus Zaddach, 1884
Euura flavipes Cameron, 1885

North to Orkney. This species is the most frequently recorded sawfly, albeit a minority of records might actually apply to E. triandrae if the host tree was misidentified (Musgrove, 2024).

See Liston et al (2017) for determination of adults. Males are rare. Within this group, males of Euura proxima, bridgmanii and triandrae cannot be separated.

Euura proxima larvae feed on a range of narrow-leaved willows causing coffee bean shaped galls that transect the leaf blade but grow more on the upper surface . Often many galls per leaf. Galls do not always contain an egg or larva and empty decoy galls may serve to attract predators away from larvae. The galls are green becoming reddish above and usually knobbly or ribbed. As the larvae mature they make a hole in the gall through which frass is expelled. Larvae sometimes leave the gall temporarily to feed on the leaf blade. 

Jump to other group proxima species

Size: Female: 2.9 - 4.6mm, male: approx. 3.2mm

GB IUCN status: Least Concern
GB rarity status: None

Distribution: England, Scotland, Wales, Ireland

Flight period: Bi- or multivoltine

Plant associations: Salix fragilis (preferred), Salix alba and hybrids (various narrow-leaved willows)

The National Biodiversity Network records are shown on the map below. (See terms and conditions)

References:

Al-Saffar, Z. Y. & Aldrich, J. C. 1997: Factors influencing the survival of Pontania proxima that attack crack willow Salix fragilis. - Biology and environment: Proceedings of the Irish Academy. Section B., Dublin 97B(3): 219-223

Al-Saffar, Z. Y. & Aldrich, J. C. 1998: Pontania proxima (Tenthredinidae: Hymenoptera): natural enemies and defensive behavior against Pnigalio nemati (Eulophidae: Hymenoptera). - Annals of the Entomological Society of America, Lanham/Maryland 91(6): 858-

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

Carleton, M. 1939: The biology of Pontania proxima Lep., the Bean Gall Sawfly of willows. - The Journal of the Linnean Society of London, Zoology, London 40: 575-624.

Higton, R. N. 1991: Studies in gall induction with special reference to the Pontania-Salix system. - Doctoral dissertation, University of Oxford : 351 pp.

Kehl, A.; Rambold, G. 2010: Interference of host plant morphology and phenology and their correlation with abundance patterns of the leaf galling sawfly Pontania proxima. - Population ecology: a publication of The Society of Population Ecology, Tokyo : 8p

Liston, A.D., Heibo, E., Prous, M., Vårdal, H., Nyman, T. and Vikberg, V., 2017. North European gall-inducing Euura sawflies (Hymenoptera, Tenthredinidae, Nematinae). Zootaxa, 4302(1), pp.1-115.

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

Musgrove, A.J. 2024. A review of the status of sawflies of Great Britain - Phase 3: The Tenthredinidae (subfamily Nematinae). Natural England, unpublished