Taxonomy
Neoascia tenur
Distribution
Species Biology
Preferred environment
Wetland; flushes and streams in blanket bog, around the periphery of raised bogs, acid and rich fen, humid, oligotrophic grassland, pond and lake margins and along brooks. In Ireland, this is a species of fen, marsh and humid, seasonally flooded grassland. But it is an insect associated with oligotrophic conditions and there are no data to suggest it may take advantage of the presence of cow dung as a larval microhabitat, or that it is in other ways supported by current animal farming practices, except in that it can occur in Ireland in association with (and has been bred from) constructed wetlands, introduced to farmland for treatment of livestock waste. Neither is this an insect which occurs in association with garden compost heaps or garden ponds. As general nutrient levels increase in farmland, with persistent use of fertilisers, this species can be expected to decrease.
Adult habitat & habits
Flies low among and settles within, dense vegetation, usually close to water and as a result its presence is more easily recognised by sweeping than by direct observation.
Flight period
End April/September, with peak June/July. Larva: larvae and puparia described and figured by Maibach and Goeldlin (1993), from puparia collected at around the level of the water-surface, within stem sheaths of dead Typha, in a slow-moving stream.
Flowers visited
Caltha, Cicuta virosa, Filipendula ulmaria, Potentilla erecta, Ranunculus, Salix repens.
Irish reference specimens
In the collections of NMI and UM
Determination
Barkemeyer & Claussen (1986), who figure the male terminalia. The adult insect is illustrated in colour by Bartsch et al (2009b), Stubbs and Falk (1983) and Torp (1994).
Distribution
World distribution(GBIF)
From Iceland, Fennoscandia and the Faroes (Jensen, 2001) south to Iberia and the Mediterranean; from Ireland eastwards through most of Europe into Turkey and European parts of Russia and on through most of Siberia. It is frequent in Scandinavia, from northern Norway southwards and in Atlantic parts of Europe. It is markedly less frequent in the continental and Mediterranean zones of Europe.
Irish distribution
Recorded as occurring in Ireland in Coe (1953). This species remains common and widely distributed in Ireland.
Temporal change
Records submitted to Data Centre in 2024
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References
Publications
Speight, M. C. D. (2008) Database of Irish Syrphidae
(Diptera). Irish Wildlife Manuals, No. 36. National Parks and Wildlife Service.
Department of Environment, Heritage and Local Government, Dublin, Ireland.
Speight, M.C.D. (2014) Species accounts of European
Syrphidae (Diptera), 2014. Syrph the Net, the database of European Syrphidae,
vol. 78, 321 pp., Syrph the Net publications, Dublin.