Gilpinia hercyniae - European Spruce Combhorn
A non-native species, appearing in spruce plantations from 1906 onwards. Records remained at fairly low levels, although widespread in southern England, until a major outbreak in Wales in the 1970s. This subsided and there have been no subsequent outbreaks. There are few records from northern England and none to date from Scotland. Since 1977 there are only two dated records, from 2000 and 2011, both in Surrey. It seems highly plausible that the species remains present at low density in spruce plantations (Musgrove, 2022). This species is parthenogenic in Britain with males being exceedingly rare. The female's inner apical spur of the hind tibia is shaped like a scale. Apex of the sawsheath in dorsal view is much broader than the apical breadth of the hind tibia. The underside of the thorax is dark. The costa of the fore wing is yellow and the stigma is yellow with a dark margin and base.
Larvae feed singly on spruces, especially Norway Spruce. They prefer older needles.
Size: 6 - 8mm
GB IUCN Status: Data Deficient
GB Rarity Status: Nationally Rare
Distribution: England, Wales
Flight period: Bivoltine, May to June, and sometimes July to September
Plant associations: Picea spp., especially excelsa (Norway Spruce).
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
Musgrove, A.J. 2022. A review of the status of sawflies of Great Britain - Phase 1: families other than Tenthredinidae. Natural England, unpublished