Taxonomy

Didea fasciata

Distribution

Species Biology

Preferred environment

Forest; most types of deciduous and coniferous forest and conifer plantations. D. fasciata is an inhabitant of both deciduous and coniferous forests. While still found in deciduous woodland situations in Ireland, this species has now managed to colonise conifer plantations here to a significant extent. What is surprising is that the third European Didea species, D. intermedia (Loew), remains unrecorded from Ireland, associatedas it is with humid pine forests up to the level of the tree line in continental Europe. D. intermedia can be expected to colonise pine plantations in Ireland sooner or later, and care should be taken in determination of Didea specimens derived from Irish conifer plantations in case D. intermedia is among them.

Adult habitat & habits

Tracksides, clearings etc.; fast-flying, frequently flies around tree foliage at some height; males patrol flowering trees, zig-zagging rapidly among the branches.

Flight period

May/September, with scattered records for October. Larva: described and figured by Heiss (1938) and illustrated from a preserved specimen in Rotheray (1994); aphidophagous larvae arboreal, on both conifers and deciduous trees; Laska & Stary (1980) provide data on larval biology.

Flowers visited

White umbellifers; Arbutus unedo, Chaerophyllum, Crataegus, Galium, Hedera, Hypochoeris, Polygonum cuspidatum, Rubus fruticosus, R.idaeus, Sambucus, Urtica dioica, Viburnum opulus.

Irish reference specimens

In the collections of NMI and UM

Determination

Stubbs & Falk (1983). See Key provided in StN Keys volume.The male terminalia are figured by Vockeroth (1969). The adult insect is illustrated in colour by Kormann (1988), Stubbs and Falk (1983) and Torp (1994).

Distribution

World distribution(GBIF)

Fennoscandia south to the Pyrenees and Spain; Italy and Greece; from Ireland eastwards through Eurasia to the Pacific coast; in N America from British Columbia south to New Mexico and east to New York; in the Oriental region to N India and Formosa.  D. fasciata is widely distributed in Ireland, though not common. The same may be said of it in most of Europe. It occurs outside Europe through Asiatic parts of the Palaearctic region to the Pacific and also extensively in the Nearctic region.

Irish distribution

Recorded as occurring in Ireland in Coe (1953). D. fasciata is widely distributed in Ireland, though not common. The same may be said of it in most of Europe. It occurs outside Europe through Asiatic parts of the Palaearctic region to the Pacific and also extensively in the Nearctic region.

Temporal change

Records submitted to Data Centre in 2020

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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.

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