Xyela curva - Curved Daggertail
The three species of Xyela can be difficult to identify from single specimens due to the few available characteristics. Three records exist, from Thetford Forest in 1985 and Newborough Warren in 2009 and 2010. The sawfly could be present more widely in plantations (Musgrove, 2022).
Males and females are piceous to brown. The male is pale around the eyes and mouth and with reddish legs and is best identified by genital dissection. The female abdomen is laterally pale and pale along the posterior margins of the tergites. The hind claws have a small subapical tooth. The hind femora is mostly pale with a dark longitudinal stripe on the anterior face. The sawsheath is distinctly curved downwards.
Xyela curva larvae feed on the developing pollen in immature male cones causing the cones to become bent out of shape. Several larvae may feed in each cone. Larvae emerge and drop to the ground to pupate. They hatch the next spring or may enter diapause for two to three years. The pupa has free legs and can run around on the surface before the adult emerges from the exuvia.
Size: approx. 2.5 - 4.5mm
GB IUCN Status: Data Deficient
GB Rarity Status: Nationally Rare
Distribution: England, Wales
Flight period: Mid-April to mid-May
Plant associations: Pinus nigra (Austrian Pine).
Blank, S.M., 2002. The Western Palaearctic Xyelidae (Hymenoptera), pp. 197-233. In: Viitasaari, M. (editor), Sawflies (Hymenoptera, Symphyta) I. A review of the suborder, the Western Palaearctic taxa of Xyeloidea and Pamphiloidea, Tremex, Helsinki
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 Natural England, unpublished