Pseudohemitaxonus sharpi - Sharp's Fern-sawfly

A rare or overlooked species, with only 10 records in total, spread from Sussex to south-west Scotland with little clear pattern. Since 1990, the only records have come from Trawscoed in North Wales  in 2017 and Keldy Ponds in the North York Moors in 2019 (Musgrove, 2023).

Overall a black sawfly with pale legs. The front lobe of the mesonotum, the scutellum, the stigma, the mesopleura and most of the abdomen are black. The abdomen has some degree of brown from the middle to the apex.

Pseudohemitaxonus sharpi larvae have not been observed in Britain but are known to feed on Lady Fern in Finland.

Jump to information on the genus Pseudohemitaxonus

Size: 4 - 5.5mm

GB IUCN Status: Near Threatened
GB Rarity Status: Nationally Rare

Distribution: England, Scotland, Wales

Flight period: May to June

Plant associations: Filices incl. Athyrium filix-femina (ferns incl. Lady Fern)


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.

Musgrove, A.J. 2023. A review of the status of sawflies of Great Britain - Phase 2: The Athaliidae and the Tenthredinidae (excluding Nematinae). Natural England, unpublished

Vikberg, V., 2010. Pseudohemitaxonus sharpi (Cameron)(Hymenoptera: Symphyta: Tenthredinidae) in Finland. Sahlbergia vol.16.1, 11-16