Taxonomy
Cheilosia pubera
Distribution
Species Biology
Preferred environment
Forest/open ground/wetland; unimproved montane pasture and fen carr and beside streams in Fagus/Picea forest. In the Alps this is primarily a species occurring close to water in open areas within Picea forest from 700m to 1000m, though records range from 400m to 2000m. Records from alpine pasture at higher altitudes are often due to confusion with the closely similar C. grisella. In the West of Ireland the altitudinal range from sea level to 400m appears to be roughly equivalent, faunistically, to the 700-1000m range in the Alps, but Picea is not native to Ireland and any indigenous forest which was present has been almost completely eradicated, and has entirely vanished from above 250m. Under these circumstances, it is perhaps surprising C. pubera has survived in Ireland at all. The record from totally treeless montane slopes in Sligo, rather than being regarded as an anomaly, could be interpreted as an indication that C. pubera has persisted here in its montane environment despite forest loss, since the species can occur in similar open situations elsewhere. Its occurrence in thick fen carr by L. Neagh, at Masserene, has no parallels in central Europe, but does mirror lowland records from Britain. These rather curious habitat details would presumably become more comprehensible were the larval food plant(s) to become more certainly known - one of them is supposedly Caltha, but nothing definitive has been published to confirm this.
Adult habitat & habits
Adults are low flying, over ground vegetation in grassland and in open areas along streams within forest, settling on the foliage of large leaved plants.
Flight period
End April/June at lower altitudes and June/July at higher altitudes/more northerly latitudes. Exceptionally, there appears to be a second generation in Ireland, July/August. Larva: undescribed. This species occurs in at least two rather different types of situation. This may be due to the larvae having plant hosts with rather distinctly different ecological requirements. The morphology of the chorion of the egg is figured by Kuznetzov (1988).
Flowers visited
Acer platanoides, Caltha, Cardamine, Prunus padus, Pulsatilla alpina, Ranunculus,Taraxacum.
Irish reference specimens
In the collections of UM
Determination
See key to males of European Nigrocheilosia species in the StN Keys volume; Barkalov and Ståhls, (1997) figure the male terminalia. Females of this species are not satisfactorily dealt with in keys at present. The adult insect is illustrated in colour in Bartsch et al (2009b), Stubbs and Falk (1983) and Torp (1994). C. pubera has a quite different appearance in the figures provided by Bartsch et al (2009b) and Stubbs and Falk (1983).
Distribution
World distribution(GBIF)
Fennoscandia, the Ardennes, northern Spain (Cordillera Cantabrica) and the Alps; from Ireland eastwards through northern and central Europe (plus mountainous parts of northern Italy and the former Yugoslavia) into European parts of Russia.
Irish distribution
Added to the Irish list by Speight et al (1975). Nash and Speight (1976) cite further records of C. pubera from the locality given in Speight et al (1975). Occurrence of this species in Ireland would be expected to be restricted to the north and west, with perhaps additional records from mountainous country elsewhere in the island, given what is known of its general ecology. It's primary association with forested biotopes would render it scarce in Ireland at all altitudes today, due to loss of forest cover during the historic period and the widespread and intensive overgrazing by sheep, to which all montane environments have been subject in Ireland recently, would ensure that montane populations of this hoverfly occurring away from forest are now also under extreme threat. The fact that C. pubera has been recorded from only two Irish stations so far is thus very probably a reasonable reflection of its status in Ireland. Also, the factors most likely to have led to the scarcity of this species here are still operating, so it should be regarded as threatened in Ireland and as an appropriate candidate for inclusion on lists of species requiring protection in the island.
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.