Taxonomy
Microdon myrmicae
Distribution
Species Biology
Preferred environment
Wetland/open ground and Betula/Pinus swamp forest; characteristic of the ecotone between wetland (raised bog and fen) and humid grassland or heath; under certain conditions may also occur within wetland (where the host ant can establish long-lived colonies in tussocks that remain above the level of seasonal flooding, e.g. around bog woodland), or unimproved, humid grassland, for instance along the edge of brook floodplain systems. This wetland species occurs in association with fen and the margins of raised bog and cutover bog (including blanket bog) in Ireland. It has been found most abundantly on a site (All Saints bog) where indigenous bog woodland of Betula is present on an ancient fen now in transition to raised bog. M. myrmicae occurs at that site in nests of the ant Myrmica scabrinodis, in huge, ancient tussocks of moss mixed with Eriophorum and Vaccinium oxycoccus.
Adult habitat & habits
Flight period
May/June. Larva: larval and puparial features are figured by Schonrogge et al (2002a). Gammelmo and Aarvik (2007) provide high quality coloured photographs of the larva, the puparium and the anterior spiracular processes of the puparium. See also the key provided in this volume. Schonrogge et al (2002a) established that M. myrmicae lives in nests of the ant Myrmica scabrinodis, in wet situations (available information suggests that the ant occurs in a much wider range of habitats than M. myrmicae, though this situation could change as M. myrmicae becomes better known - especially once data are available from parts of continental Europe). The developmental stages of M. myrmicae have been found with this ant in tussocks of grasses, moss (including Sphagnum) and sedge. A coloured photo of typical M. myrmicae habitat is provided by Gammelmo and Aarvik (2007). It is not yet known whether M. myrmicae can occur with Myrmica vandeli (Bondroit), which is apparently parasitic upon M. scabrinodis and replaces it, such that erstwhile M. scabrinodis nests in wetland can quite rapidly become M. vandeli nests (Elmes et al, 2003). However, Stankiewicz (2003) confirms the occurrence of M. myrmicae with species of Myrmica other than M. scabrinodis, namely M. gallienii and M. rubra. The puparia of M. myrmicae tend to be found in the uppermost galleries of the ant in the highest part of the nest, just below to outer layer of vegetation roofing the nest.
Flowers visited
Not known to visit flowers.
Irish reference specimens
In the collections of NMI
Determination
See keys provided in the StN Keys volume. M. myrmicae was described by Schonrogge et al (2002a, 2002b) from the developmental stages, used by those authors to distinguish this taxon from other European Microdon species. Speight (2002a) provides an additional feature for distinguishing M. myrmicae from M. mutabilis (L.) sensu Schonrogge et al, based on the larval mouthparts. M. myrmicae would be keyed out as M. mutabilis in Doczkal and Schmid (1999). The adult fly may be distinguished from other European Microdon species except M. mutabilis, using the keys provided by Doczkal & Schmid (1999). Separation of the adults of M. mutabilis and M. myrmicae cannot be carried out with confidence at present, but these species do exhibit reliable morphological differences in at least the puparium. The adult of M. myrmicae is of somewhat smaller size than the average M. mutabilis specimen, though small specimens of M. mutabilis are similar in size to M. myrmicae. Its close similarity to M. mutabilis can be seen from the coloured photo provided by Gammelmo and Aarvik (2007). Until and unless more precise features can be defined for separation of the adults of these species, their ecology may remain the best guide to which is present in a locality - a record from dry grassland suggests M. mutabilis, whereas one from wetland suggests M. myrmicae. But to confirm the presence of the species would at present necessitate search for larvae or puparia in nests of the appropriate ant species, at an appropriate time of the year, which can be a laborious and destructive process. The general appearance of M. myrmicae is shown in the coloured figure provided by Bartsch et al (2009b).
Distribution
World distribution(GBIF)
Uncertain, due to confusion with M. mutabilis. At present, the presence of this species is confirmed from Ireland, Great Britain, the Netherlands, Germany, France, Norway, Poland and parts of European Russia (Karelia). Confirmation of the presence of this species is dependent upon availability of determined larval or puparial material.
Irish distribution
Added to the Irish list by Speight (2002); presence in Ireland confirmed by Speight (2003). It can be presumed that records of "Microdon mutabilis" from wetland sites in Ireland refer to this species (see Speight, 2002), but such records are few and scattered (see accompanying distribution map). This species has to be regarded as a candidate for inclusion in any list of invertebrates requiring protection throughout 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.