EUURA AMERINAE GROUP

Euura amerinae - Bay Willow Shoot-galler

Cynips amerinae Linnaeus, 1758
Tenthredo salicis pentandrae Retzius, 1783
Tenthredo saliceti Fallén, 1808
Nematus medullarius Hartig, 1837
Nematus populi Hartig, 1837
Nematus buccatus Thomson, 1863
Pontania jorgenseni Strand, 1908
Nematus impunctatus Herrich-Schäffer, 1840
Cryptocampus pentandrae (Retzius, 1783)

Northern and western Britain, more occasional in south-east where foodplant occurs (Musgrove, 2024). See Liston et al (2017) for determination of adults. 

Larvae feed on shoots of Bay Willow causing a large walnut shaped gall to form on one side of the shoot, often bent and containing several larvae.

Size: Female: 3.5 - 5.1mm, male: 3.8 - 6.0mm

GB IUCN Status: Least Concern
GB Rarity Status: None

Distribution: England, Scotland, Wales, Ireland

Flight period: Univoltine

Plant associations: Salix pentandra (Bay Willow)

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

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.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 Natural England, unpublished