Taxonomy
Parhelophilus versicolor
Distribution
Species Biology
Preferred environment
Wetland/freshwater; fen, marsh and reed beds with patches of standing water, also along canals and water-filled ditches. P. versicolor can occur in water that is more nutrient-rich than can be tolerated by P. consimilis and can be expected wherever the larger species of bulrush (T. latifolia) is to be found in standing water, its larvae occurring just below the water surface on decaying Typha stems, beneath the outer stem-sheathing leaves. However, this hoverfly can occur in the absence of Typha, which is the case in many of its Irish localities. P. versicolor is an insect of water bodies in marsh and fen, rather than bog habitats, and can sometimes be found in farmland in Ireland, in association with permanent pools/ponds or permanently water-filled ditches. It can also occur in Ireland in association with constructed wetlands, introduced to farmland for treatment of livestock waste. It does not seem to be found in association with temporary water bodies, or with garden ponds. Its tolerance for eutrophication thus lies somewhere between that of P. consimilis (intolerant) and Helophilus pendulus (very tolerant).
Adult habitat & habits
Flies very fast, with a characteristic, high-pitched whine and a zig-zag flight, within stands of tall vegetation (e.g. Scirpus, Phragmites) bordering fen pools etc.; males hover at 1 - 2m over animal tracks etc. in reed beds; settles on emergent vegetation, e.g. Menyanthes, Typha.
Flight period
May/August (plus April and September in southern Europe), with peak in June/July. described and figured by Hartley (1961), from larvae collected from decaying rhizomes of Typha, in a pond; aquatic.
Flowers visited
White umbellifers; Aegopodium podagraria, Cardamine, Cistus, Crataegus, Euphorbia, Filipendula ulmaria, Galium, Leontodon, Sorbus aucuparia.
Irish reference specimens
In the collections of NMI and UM
Determination
See Key provided in StN Keys volume, also Bartsch et al (2009b), Thompson (1997) and Reemer (2000a), who figures the male terminalia. The colour of the fore tibiae is usually used as a diagnostic feature for separation of males of this species from males of P. consimilis. However, although usually entirely yellow in males of P. versicolor, the front femora may be marked with black antero-laterally in this species, as in P. consimilis. Females of this species can be difficult to distinguish from females of both P. frutetorum and P. crococoronatus. The adult insect is illustrated in colour by Bartsch et al (2009b) and Torp (1994).
Distribution
World distribution(GBIF)
From southern Fennoscandia south to Iberia, the Mediterranean and N Africa; from Ireland eastwards through most of Europe into Turkey and European parts of Russia; in Siberia from the Urals to the River Ob. It is also widely distributed in Europe, from the southern tip of Norway to the Mediterranean, and becomes more frequent towards southern parts of the continent.
Irish distribution
Recorded as occurring in Ireland in Coe (1953). In Ireland, P. versicolor is infrequent, though widely distributed. However, it is not a threatened species here.
Temporal change
Records submitted to Data Centre in 2023
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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.