Arge enodis - Clouded Fusehorn

Arge enodis is one of the black species. With only a single post-1950s record from 1970, this species was considered extinct in Britain in the 2022 status review (Musgrove, 2022). Prior to 1970, although infrequently recorded, it was widespread in England west to Cornwall, east to Norfolk and north to County Durham. A female of the species was taken in Bedfordshire in 2022 and a second female was found in Bedfordshire in 2025. The species has a more pronounced turquoise iridescence than other black Arge species. The apex of the wing (beyond the stigma) is clear, contrasting with a deeply infuscate base. Vein 3rm in the forewing is straight distinguishing this species from the similar Arge nigripes and the apex of the sawsheath is more rounded in enodis.

Larvae feed gregariously on willows. Eggs are lain into fully developed leaves between the serrations along the leaf margin. The larvae feed from the leaf margins to the midrib. At maturity they drop to the ground and construct a cocoon just below the soil surface.

Fenili (1981) notes that the larvae have also been reported as feeding on roses, alder and bird cherry across its European range. However, this may be as a result of misidentification.

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Size: 8 - 10mm.

IUCN Status: Regionally Extinct
GB Rarity Status: Extinct

Distribution: England, Scotland

Flight period: Bivoltine, May to August.

Plant associations: Salix spp. Smooth-leaved willows including European Violet-willow, Salix daphnoides, Crack Willow, Salix fragilis, White Willow, Salix alba, and Purple Willow, Salix purpurea (Fenili, 1981)

The National Biodiversity Network records are shown on the map below. (See terms and conditions)

References:

Benson, R.B., 1952. Handbooks for the Identification of British Insects. Hymenoptera, Symphyta, Vol 6, Section 2(a-c), Royal Entomological Society, London

Fenili, G. A. 1981: Contributi alla conoscenza degli Hymenoptera Symphyta. Arge enodis (Linneo) (Tenthredinoidea, Argidae, Arginae). - Redia. Giornale di Entomologia, Firenze 64: 13-52; Tav. I

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 Natural England, unpublished