Taxonomy
Syrphus rectus
Distribution
Species Biology
Preferred environment
Forest/open ground/cultures; patchy deciduous scrub and grassland, crops. Improved pasture and unimproved grassland with thickets of deciduous scrub seem to characterise the habitat of this taxon, both in Ireland and elsewhere. But its uncertain identity makes it difficult to say more than that. There are as yet no indications that its habitat range differs from that of S.vitripennis, the species with which S. rectus is so intimately confused in Europe.
Adult habitat & habits
No data.
Flight period
July/August (Europe); May/October (N America). Larva: not described. Short and Bergh (20005) illustrate the eggs of N American S. rectus, where the larva of this species is apparently a significant predator of the aphids on fruit trees, including the woolly apple aphid (Eriosoma lanigerum).
Flowers visited
No data.
Irish reference specimens
In the collections of NMI
Determination
See Key provided in StN Keys volume; Goeldlin (1996), Vockeroth (1992). There is considerable uncertainty over the status of European specimens referable to this taxon. Goeldlin (1996) drew attention to the occurrence of specimens of apparently this N American species in Europe. In N America it is known only from the female, the male being virtually indistinguishable from S. vitripennis, according to Vockeroth (1992). The female specimens consigned to this species by Goeldlin (1996) were regarded as sufficiently different to warrant designation as a separate subspecies, S. rectus bretolensis. His key separates these European specimens from the other Syrphus species known in Europe, but it has to be recognised that, even if the N American material consigned to this taxon represents a separate species, there is no certainty that European specimens consigned to S. rectus either belong to that species or to any discrete taxon. The female looks superficially like S.ribesii, in its possession of almost entirely yellow legs, but may be distinguished from that species through possession of wings with extensive areas bare of microtrichia. In these characters it resembles S. sexmaculatus, from which it may be distinguished by having black peg-like bristles beneath the mid-tarsi and a more extensively yellow frons. Ssymank et al (1999) tentatively synonymise S. rectus bretolensis with S. vitripennis, but without explanation. There is clear need for the correct taxonomic status of European S. rectus-type females to be established. Until a satisfactory basis exists for decision, it is practical to give separate identity to this taxon, so that the frequency and geographic extent of its occurrence can be better documented. For further discussion of this enigmatic taxon, see Speight (1999a).
Distribution
World distribution(GBIF)
Uncertain, due to confusion until recently with other European Syrphus species; its presence is so far confirmed from Finland, Denmark, Ireland, Luxembourg, Germany, France/Switzerland (Col de Bretolet). In N America it is known from southern Canada south to Colorado. This species may be to a significant extent migratory. S. rectus was first recognised as a European species by Goeldlin (1996), based on material from central Europe, but it is still unclear whether, in Europe, this taxon is a separate species or a variety of Syrphus vitripennis (Mg). There is a reasonable basis for accepting that, in N America, S. rectus is a distinct species, which occurs together with S. vitripennis (Vockeroth, 1992). It is treated here as a distinct species.
Irish distribution
Added to the Irish list by Speight (1999b). One Irish specimen referrable to this taxon has been collected in Co. Donegal, another in Dublin and the third in Co. Cork, all of them from the end of August/beginning of September. Given its uncertain taxonomic status, the conservation status of this taxon in Ireland has to be regarded as indeterminate.
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.