Taxonomy
Trichopsomyia flavitarsis
Distribution
Species Biology
Preferred environment
Wetland; rich and acid fen, marsh, boggy moorland, including Myrica stands; oligotrophic Molinia grassland (formed by invasion of old peat cuttings); brook floodplains; tall herb open areas in Alnus incana alluvial forest; humid, unimproved grassland with flushes in montane and subalpine pasture and Pinus mugo ssp. uncinata forest; towards the southern fringe of its range also in humid deciduous forests. In Ireland this species occurs in various wetland situations. In the east of the island it is not infrequent beside streams and in boggy moorland in mountainous country. In the Midlands it is frequent in poorly drained pasture with Juncus, around raised bogs and in fenland. In the west it may be found in all of these situations, plus wet hollows and Schoenus fen in the karst limestone grasslands and also in the landward parts of machair systems. It may be found in large numbers in the Burren. Its larvae are associated with Juncus and it is much less frequent in most parts of the Atlantic zone than in Ireland. This is not an insect of the standard farm landscape of green fields and hedges, or of conifer plantations.
Adult habitat & habits
Flies low among dense vegetation; males hover in groups within 2m of the ground, beside small bushes, rocks etc. This species is as easily located by use of a sweep net as by direct observation.
Flight period
May/July, with some specimens into August, especially at higher altitudes. Larva: described by Rotheray (1997) and incorporated into the keys provided by Rotheray (1994), where it is distinguished from larvae of related genera; a predator of a gall-making psyllid (Homoptera) on the stems of a Juncus species.
Flowers visited
Berteroa incana, Frangula alnus, Narthecium, Potentilla, and Ranunculus.
Irish reference specimens
In the collections of NMI and UM
Determination
See key provided in StN Keys volume, plus Verlinden (1991) and Goeldlin (1997). Care is still needed to distinguish the adults of this species from those of T. lucida, and it is doubtful that these two species could be effectively separated until Verlinden's (1991) keys appeared. The adult of T. flavitarsis is illustrated in colour by Bartsch et al (2009b), Stubbs and Falk (1983), Torp (1984, 1994) and van der Goot (1986). The male terminalia are figured by van der Goot (1981), Verlinden (1991) and Goeldlin (1997).
Distribution
World distribution(GBIF)
From Fennoscandia south to the Pyrenees and northern Spain; from Ireland eastwards through northern Europe and mountainous parts of central Europe into European parts of Russia and on to the Pacific coast; also in the former Yugoslavia. It is probably most frequent in the Atlantic zone of Europe, becoming very localised further north and in central Europe. It is not recorded from the Mediterranean zone. Its range extends through northern Europe into Siberia and thence eastwards across to the Pacific.
Irish distribution
Recorded as occurring in Ireland in Coe (1953). T. flavitarse is frequent in the west of Ireland, and in wetland/humid grassland in the midlands. This species is not threatened in Ireland, but neither is it generally distributed here.
Temporal change
Records submitted to Data Centre in 2024
The following map is interactive. If you would prefer to view it full screen then click here.
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.