Taxonomy
Cheilosia psilophthalma
Distribution
Species Biology
Preferred environment
Open ground/forest: open, grassy areas within sparse woodland and unimproved, montane/subalpine grassland from above 1500m, down to grassy, open areas within karstic Quercus pubescens forest. until recently, this species has been totally confused with C. urbana (Meigen) in literature. As yet, insufficient is known of C. psilophthalma for difference between its ecology in Ireland and elsewhere to have become apparent. To some extent, the paucity of Irish records must reflect the species' early flight period, but its apparent association with unimproved, reasonably well-drained, oligotrophic, low altitude grassland and scrub also requires to be taken into consideration in considering its status, given the scarcity of this habitat in Ireland. The larvae are known to develop in the aerial parts of Hieracium pilosella and H. caespitosum. It remains an enigmatic species, not least because all Irish records are based on single specimens. It is a pronouncedly anthropophobic insect in Ireland, entirely absent from the standard farmland landscape of green fields and hedges, from conifer plantations and from suburban gardens and parks.
Adult habitat & habits
Settles on low-growing vegetation, e.g. clumps of dead Molinia and visits flowers of shrubs.
Flight period
April/May and on to July at higher altitudes. Larva: not described, but reported by Grosskopf et al (2001) as developing in the aerial parts of Hieracium pilosella and H. caespitosum. The species evidently overwinters as a puparium, among ground surface litter.
Flowers visited
Acer platanoides, Anemone nemorosa, Primula veris, Prunus spinosa, Salix spp., including S. repens.
Irish reference specimens
In the collections of NMI
Determination
Claussen and Kassebeer (1993) and Speight (1996) distinguish this species from the closely similar C. latigenis, C. mutabilis (Fallen) and C. urbana Meigen. Claussen & Doczkal (1998) provide distinctions from C. vujici; another closely related central European species. Various of these authors figure the surstyli of the male terminalia, as do Stubbs and Falk (2002). In other recent keys this species would usually key out to C. urbana, but without certainty, since C. psilophthalma can have antennae that are from pale orange to almost black, and the keys do not accommodate this range of variation. The closely-related C. urbana often occurs in great numbers, but, inexplicably, only single individuals of C. psilophthalma are usually found. Added to the Irish list by Speight (1978c), under the name praecox (Zetterstedt). The known Irish material of C. praecox was reviewed by Speight (1996b), resulting in withdrawal of praecox from the Irish list and recognition of all Irish specimens as belonging to C. psilophthalma.
Distribution
World distribution(GBIF)
Uncertain, due to confusion until recently with C. latigenis and C. urbana, but confirmed from southern Norway, Sweden, southern Finland, Ireland, Britain, France (Vosges, Alps, Cevennes), Poland, Switzerland, Greece, Montenegro, Serbia and European Russia. Elsewhere in the Atlantic zone of Europe it was until recently only known from the Netherlands, but a few scattered localities are also now known for the species in Britain. In central Europe this species becomes more frequent in the Alps, along the tree line in unimproved alpine grassland. It appears to be endemic to Europe.
Irish distribution
The few Irish records of C. psilophthalma are from the southern half of the island. It has to be regarded as threatened here and would be a candidate for inclusion in any national list of Irish insects requiring protection.
Temporal change
Records submitted to Data Centre in 2024
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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.