Taxonomy
Platycheirus rosarum
Distribution
Species Biology
Preferred environment
Wetland/freshwater; pond, stream and river margins with tall herb vegetation and fen, around the periphery of raised bogs, Salix swamp, also humid, seasonally-flooded, unimproved grassland. The habitat range occupied by P. rosarum in Ireland is very similar to that of P. granditarsus, and these two species may often be found together. Also, what can be said of the impact of intensification of farming activity on P.granditarsus applies to P. rosarum (see P. granditarsus species account). P. rosarum is more a species of the ecotone between deciduous woodland and wetland than is P. granditarsus, but both typically occur where tall herb vegetation is found in seasonally-flooded grassland.
Adult habitat & habits
Flies among tall waterside and fen vegetation; males hover within 2m of the ground in sparsely vegetated patches.
Flight period
May/September. Larva: not described. The morphology of the chorion of the egg is figured by Kuznetzov (1988).
Flowers visited
Caltha, Knautia, Lythrum, Potentilla erecta, Ranunculus.
Irish reference specimens
In the collections of NMI and UM
Determination
van der Goot (1981). Until recently, this species was consigned to a separate genus, Pyrophaena. Vockeroth (1990) argues convincingly that Pyrophaena should be synonymised with Platycheirus. The male terminalia are figured by Dusek and Laska (1967). The adult insect is illustrated in colour by Stubbs and Falk (1983), Torp (1984, 1994) and van der Goot (1986).
Distribution
World distribution(GBIF)
From Fennoscandia south to Iberia and the Mediterranean; from Ireland eastwards through most of Europe (extremely localised in the Alps) into European parts of Russia; in Siberia from the Urals to the Altai; in N America from Alaska to Nova Scotia and south to New Jersey. It has a wide range of Europe and onwards into Asiatic parts of the Palaearctic and occurs also in the Nearctic. Only in mountainous parts of central Europe is it anywhere regarded as threatened.
Irish distribution
Recorded as occurring in Ireland in Coe (1953). P. rosarum is generally distributed in Ireland, though largely absent from the standard farmland landscape of green fields and hedges.
Temporal change
Records submitted to Data Centre in 2025
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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.