Synonyms and other taxonomic changes
Syrphus obesus Fabricus 1775
Musca obesa Gmelin 1790
Volucella obesa Wiedemann 1830
Ornidia obesa Lepeletier & Serville 1828
Volucella obesoides Giglio-Tos 1892
Ornidia obesoides Curran 1930
Identification
Body shiny, metallic, green or purplish-blue. Wings mostly hyaline, but with two spots along anterior margin: one near middle, the other smaller and before the apex. Scutellum with a shallow transverse depression before posterior edge.
Range
Widespread and common in the New World tropics...reaching north into our area from Colorado east to Massachusetts and New York (also in Hawaii).
Native to New World tropics; historically had spread to various tropical islands of the Pacific & Indian Ocean, and to parts of tropical Africa (see
GBIF map), but has become less common in the Old World with improved sanitation [Thompson(1991)]
Habitat
Has been found breeding in semiliquid synanthropic material, such as animal dung, human feces, sewage, and rotten fruits and vegetables [
(1), Martins et. al. (2010)].
A hemisynanthropic species, meaning one associated with and making use of resources available in (often rural) human settlements, but not restricted to or entirely dependent on such habitat.
Remarks
Known to carry bacteria of public health importance (Salmonella, Shigella, Mycobacterium) [Thompson(1991), Martins et. al.(2010)]
Maggots convert coffee-production waste into protein sources for cattle feed [Lardé(1990)]
In a large scale study of the role of insects in reclamation of urban solid waste through compost (sampling 4000 kg, i.e. more than 8.4 tons), undertaken in the tropics (near Medellín, Columbia), more than 95% of the insects present were found to be dipterans, and of those O. obesa was highly important as the dominant species present throughout the process [Morales & Wolff(2010)].
Print References
Lardé, G. (1990). Growth of
Ornidia obesa (Diptera: Syrphidae) larvae on decomposing coffee pulp. Biological Wastes 34: 73−76. (
Abstract)
Martins, E., Neves, J. A., Moretti, T. C., Godoy, W. A., & Thyssen, P. J. (2010). Breeding of
Ornidia obesa (Diptera: Syrphidae: Eristalinae) on pig carcasses in Brazil. Journal of Medical Entomology, 47(4), 690–694. (
Full Text)
Morales, G.E. & Wolf, M. (2010). Insects associated with the composting process of solid urban waste separated at the source. Revista Brasileira de Entomologia 54(4): 645–653 (
Full Text)
Rotheray G. E., Hancock E. G., Marcos-García M. A., Zumbado M. (2005). Early stages and breeding sites of three species of Neotropical Ornidia (Diptera, Syrphidae). Studia Dipterol. 12: 419–427.
Thompson F. C. (1991). The flower fly genus
Ornidia (Diptera: Syrphidae). Proc. Entomol. Soc. Wash. 93: 248–261 (
Full Text)
Internet References
"Zoomable" specimen image from the Smithsonian insect collection.
GBIF species page, with distribution map, images, and other info.
