Taxonomy
Helophilus pendulus
Distribution
Species Biology
Preferred environment
Freshwater/wetland; an anthropophilic species which has become ubiquitous in some regions of Europe because of its ability to use a wide range of standing water and sub-aqueous habitats for larval development. This syrphid is markedly anthropophilic, occurring in garden ponds, rain-water barrels, silage seepage, wet ditches etc. and various more natural situations in which water-sodden vegetable matter accumulates, including shallow, temporarily water-filled depressions on the surface of bog. In Ireland, H. pendulus is almost ubiquitous, and omnipresent in farmland. It can occur in Ireland in association with (and has been bred from) constructed wetlands, introduced to farmland for treatment of livestock waste.
Adult habitat & habits
Flies low over and among waterside vegetation; also found away from water along woodland tracks, in suburban gardens, along field hedges, in pasturage etc.
Flight period
April/October (March in southern Europe and stragglers on into November). Larva: described and figured by Hartley (1961) and illustrated in colour (apparently from a preserved specimen) by Rotheray (1994). Larvae occur in standing water of ponds (including garden ponds), canals, wet ditches, open tree hollows and garden water butts and in sub-aqueous decaying vegetable matter such as cow-dung, wet compost heaps and slurry pits.
Flowers visited
Compositae; Rosaceae, including flowering understorey trees; Umbelliferae and a wide range of other white and yellow flowers (see de Buck, 1990), including Berberis, Menyanthes, Polygonum and Salix; also at pink flowers such as Cirsium and Succisa.
Irish reference specimens
In the collections of NMI and UM
Determination
See Key provided in StN Keys volume. The adult insect is illustrated in colour by Bartsch et al (2009b), Haarto & Kerppola (2007), Kormann (1988), Stubbs and Falk (1983) and Torp (1994).
Distribution
World distribution(GBIF)
Very widely distributed in Ireland, and more frequent here than in most other parts of Europe. This species also has an extensive range outside Europe.
Irish distribution
Recorded occurring in Ireland in Coe (1953). H. pendulus is abundant and well-nigh ubiquitous in Ireland and over most of Europe, except in the Mediterranean zone, where is becomes more localised, occurring in humid forest and wetland.
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.