Added by Liston and Blank in 2006. The three species of Xyela can be difficult to identify from single specimens due to the few available characteristics.
Males and females are piceous and more or less marked with yellow. The female head is usually extensively yellow. Adults may be found on neighbouring birch trees when in flower.
Xyela julii 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. They can be swept from birch trees in flower or from herbaceous vegetation at ground level adjacent to pines. Larvae emerge from the cones 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 - 3.5mm
Distribution: England, Scotland, Wales, Ireland
Flight period: Mid-March to mid-May
Plant associations: Pinus spp. (pines) incl...
Pinus sylvestris (Scots pine) preferred (1)
Pinus nigra (Austrian pine) (2)
1. Benson, R.B., 1952. Handbooks for the Identification of British Insects. Hymenoptera, Symphyta, Vol 6, Section 2(a-c), Royal Entomological Society, London
2. 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
3. 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