Acantholyda posticalis - Keeled Pine Spinner

Acantholyda posticalis is one of two species in this genus in Britain. Records have historically been distributed widely across Britain. However, recent years have seen a contraction to what might be considered to have been a natural range in Caledonian pinewoods, with almost none seen around more recently planted pines in the south of the range (Musgrove, 2022). The head and thorax are richly marked with cream on a black background. The abdomen is black above with orange sides and white underside. 

Larvae feed on pine in communal webs.

Jump to other Pamphiliidae

Size: 11 - 15mm

GB IUCN Status: Near Threatened
GB Rarity Status: None

Distribution: England, Scotland, Wales

Flight period: May to July

Plant associations: Two-needled pine trees (Pinus spp) including Pinus sylvestris (Scots Pine) and sometimes Pinus nigra (Austrian pine).

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, 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 Natural England, unpublished

Viitasaari, M. ed., 2002. Sawflies (Hymenoptera, Symphyta), I: a review of the suborder, the Western Palaearctic taxa of Xyeloidea and Pamphilioidea (Vol. 1). Tremex Press.