This species was previously conflated with Fenella nigrita. A very little-known species, only reported on four occasions to date, as both adult insects and leaf-mines. Records are distributed from Yorkshire north the Speyside, matching the core range of Wood Crane's-bill in Britain (Musgrove, 2023).
Fenella monilicornis has long antennae (twice the breadth of the head) with 13 to 16 segments. The ratio of the third to fourth antennal segments is about1.2 to 1.0. Vein M is more curved in the basal one-third than in the apical two-thirds.
Larvae mine the leaves of wood crane's-bill.
GB IUCN Status: Data Deficient
GB Rarity Status: Nationally Rare
Distribution: England, Scotland
Flight period: Assumed bivoltine May to June and August to October
Plant associations: Geranium sylvaticum and possibly other Geranium spp. (possibly wood crane's-bill and other crane's-bills)
Benson, R.B., 1952. Handbooks for the Identification of British Insects. Hymenoptera, Symphyta, Vol 6, Section 2(a-c), Royal Entomological Society, London
Benson, R. B. 1953: Some changes and additions to the list of British sawflies with the descriptions of two new species (Hym., Tenthredinidae). - The Entomologist's Monthly Magazine, Fourth Series, London 89(14): 150-154
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. 2023. A review of the status of sawflies of Great Britain - Phase 2: The Athaliidae and the Tenthredinidae (excluding Nematinae). Natural England, unpublished