Cluster flies (a.k.a. grass flies or attic flies) are flies of the genusPollenia in the family Polleniidae. Unlike the more familiar blow flies, such as the bluebottle genus Phormia they do not lay eggs in human food. They parasitise earthworms; the females lay their eggs near earthworm burrows, and the larvae then feed on the worms. But the biology of this group is relatively poorly known and a few have been recorded from other hosts including caterpillars and bees.[13]
Cluster flies seek refuge in cold weather and find their way into attic spaces and similar areas indoors. They often emerge on warm days, and cluster at windows attempting to exit (hence the name).[14]
The typical grass fly Pollenia rudis is about 7 mm long and can be recognised by distinct lines or stripes behind the head, short golden-coloured hairs on the thorax, and irregular light and dark grey areas on the abdomen. Cluster flies are typically slow-moving.
Cluster flies have a widespread distribution. Eight species are found in Britain and 31 in Europe. Pollenia species are also numerous in Australia and New Zealand (over 30 species); they are common in North America. P. rudis has spread widely in association with humans.[15]
^ abcdRobineau-Desvoidy, André Jean Baptiste (1830). "Essai sur les myodaires". Mémoires presentés à l'Institut des Sciences, Lettres et Arts, par divers savants et lus dans ses assemblées: Sciences, Mathématiques et Physique. 2 (2): 1–813. Retrieved 15 July 2018.
^Curran, C.H. (1927). "Some new Australasian and African Diptera of the families Muscidae and Tachinidae (Dipt.)". Entomologische Mitteilungen. 16: 345–357.
^ abcEnderlein, G (1936). "Ordnung: Zweiflügler, Diptera. In: Brohmer P, Ehrmann P, Ulmer G (Eds)". Die Tierwelt Mitteleuropas. Insekten, Teil II. 6 (22): 1–259.
^ abJacentkovský, D. (1941). "Pollenia mayeri n. sp. Calliphoridae, Tachinoidea) nová kuklice z Moravy [Pollenia mayeri n. sp. (Calliphoridae, Tachinoidea) eine neue Raupenflige aus Mähren". Entomologické listy (in Czech). 4: 14–16.
^ abcJacentkovský, D (1942). "Beitrag zur Kenntnis der gattung Pollenia R.D. (Calliphoridae, Tachinoidae, Diptera)". Rozpravy Vedecké Spolecnosti Badatelské pri Ruské Svobodné Universite v Praze. 11 (16) (84): 193–225.
^ abJacentkovský, D (1944). "Další příspěvek k zvířeně kuklkic (Tachinoidea, Dipt.) Moravy [Weiterer Beitrag zur Fauna der Raupenfliegen (Tachinoidea, Dipt.) Mährens]". Entomologické listy (in Czech). 7: 45–49.
^ abcdefghLehrer, A. Z. (1963). "Études sur les Diptères Calliphorides. I. – La classification des Polleniinae palearctiques et leur dispersion en Roumanie". Bulletin et Annales de la Société Royale d'Entomologie de Belgique. 99: 285–310.
^Sivell, Olga (2021). "Blow flies (Diptera: Calliphoridae, Polleniidae, Rhiniidae)". RES Handbooks for the Identification of British Insects. 10 (16): 1–208. ISBN9781910159064.
^Rohdendorf, B.B. (1926). "Morphologisches Studium an äusseren Genitalorganen der Calliphorinen (Diptera)". Russkii Zoologicheskii Zhurnal (in Russian). 6: 83–128.
^Wainwright, C.J. (1940). "The British Tachinidae (Diptera): Second supplement". Transactions of the Royal Entomological Society of London. 90 (14): 411–448. doi:10.1111/j.1365-2311.1940.tb01028.x.
^ abMeigen, J.W. (1826). Systematische Beschreibung der bekannten europäische n zweiflugeligen Insekten. Hamm: Vierter Theil. Schulz-Wundermann. pp. xii + 412 pp., pls. 42–54.
^ abcdMalloch, J. R . (1930). "The calyptrate Diptera of New Zealand. Part III. Family Calliphoridae". Records of the Canterbury Museum. 3: 313–324.
^ abcRognes, Knut (1992). "Revision of the cluster-flies of the Pollenia vagabunda species-group (Diptera, Calliphoridae)". Entomologica Scandinavica. 23: 95–114. doi:10.1163/187631292X00056.
^Jacentkovský, D. (1939). "Über einige interessante Sarcophagiden (Tachinariae, Diptera) aus Bulgarien". Izvestiia Na Tsarskitia Prirodonauchni Instituti V Sofiia. 12: 188–192.
^ abHardy, G.H. (1932). "Two new Australian species of Pollenia". Proceedings of the Linnean Society of New South Wales. 57: 388–340.
^ abcFeng, Y. (2004). "Five new species of the tribe Polleniini from Sichuan, China (Diptera, Calliphoridae, Calliphorinae)". Acta Zootaxonomica Sinica. 29: 803–808.
^Senior-White, R.A. (1923). "Notes on Indian Muscidæ". Memoirs of the Department of Agriculture in India. 8: 35–52.
^Malloch, J. R. (1927). "Notes on Australian Diptera, No. xi". Proceedings of the Linnean Society of New South Wales. 52: 299–335. Retrieved 23 June 2021.
^ abGrunin, K. Ya. (1966). "New and little known Calliphoridae (Diptera) mainly bloodsucking or subcutaneous parasites of birds". Entomologicheskoe Obozrenie. 45: 897–903.
^Mawlood, N. A.; Abdul-Rassoul, M. S. (2009). "A new species in the genus Pollenia Rob. -Desvoidy, 1830 (Diptera Calliphoridae)". Bulletin of the Iraq Natural History Museum. 10: 59–65.
^ abMalloch, John Russell (1936). "Notes on Australian Diptera – XXXV". Proceedings of the Linnean Society of New South Wales. 61: 10–26. Retrieved 26 June 2021.
^Macquart, J (1834). "Insectes Diptères du Nord de la France. Tome V. Athericères: Créophiles, Œstrides, Myopaires, Conopsaires, Scénopiniens, Céphalopsides. Daniel L, Lille, 232 pp". Mémoires de la Société Royale des Sciences, de l'Agriculture et des Arts, de Lille. 1833: 137–368.
^Kurahashi, H. (1987). "The blow flies of New Guinea, Bismarck Archipelago and Bougainville Island". Occasional Publication by the Entomological Society of Japan. 1: 3 unnumbered pp. + 1–99.
^Senior-White, R. A.; Aubertin, D.; Smart, J. (1923). The fauna of British India, including the remainder of the Oriental Region. Diptera (Vol. VI). Calliphoridæ. London: Taylor and Francis. p. 288.
^Zumpt, Fritz (1956). "64i. Calliphorinae". In: Lindner e (Ed.) die Fliegen der Palaearktischen Region. 11 (Lieferungen 190, 191, 193). Schweizerbart’sche Verlagsbuchhandlung, Stuttgart: 140.
^Jacentkovsky, Dimitrij (1936). "Beitrag zur Kenntnis der Raupenfliegen (Tachinariae, Diptera) Bulgariens". Bul-gariens. Izvestiia Na Tsarskitia Prirodonauchni Instituti V Sofii. 9 (109–134).
^Rognes, Dr Knut; Pape, Dr Thomas (19 April 2007). "Taxon details: Calliphoridae". Fauna Europaea version 1.1. Archived from the original on 1 November 2005. Retrieved 31 May 2008.
^Macquart, P.J.M. (1847). Diptères exotiques nouveaux ou peu connus. 2.e supplement. Paris: Roret. pp. 5–104, 6 pls.