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BugGuide Gathering
Smoky Mountains
University of Tennessee Biological Field Station
August 8-10, 2008
 
Photos from the gathering
 
Photos from the 2007 gathering in Minnesota

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Species Megaselia scalaris

Classification
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Class Insecta (Insects)
Order Diptera (Flies)
No Taxon (Aschiza)
Family Phoridae (Scuttle Flies)
Genus Megaselia
Species scalaris (Megaselia scalaris)
Numbers
the most common species of phorid fly encountered in homes and other buildings; Phoridae specialist Brian Brown estimates that 90 percent of specimens sent to him for identification are Megaselia scalaris
Size
body length of adult males 2+ mm; females 3+ mm
Identification
the female's abdominal tergite 6 is short, narrow, shiny, and extends laterally on the segment, unlike tergites of preceding segments [this feature can only be seen in a clear close-up photo taken at the proper angle, or by examination under a microscope]
Range
cosmopolitan
Habitat
larvae live in a variety of habitats: moist decaying plant or animal material, sanitation filter beds, sludge in sewer pipes and trash cans in public washrooms and homes, lab cultures of Drosophila, fresh or fermenting fruit, and sometimes in external wounds or in the digestive tract of animals, including humans
larvae display a unique behavior of swallowing air when exposed to pools of liquid; the swallowed air allows them to float, and may prevent drowning during flood conditions in their normal habitat
Season
year-round indoors
Food
larvae are scavengers on a variety of decaying organic material
Life Cycle
see family page for description of the general phorid life cycle
Internet References
pinned adult images showing diagnostic characteristic on female abdomen (Brian Brown, Los Angeles County Museum of Natural History, phorid.net)
Questions and Answers on phorid flies (Brian Brown, Los Angeles County Museum of Natural History, phorid.net)
overview of habits and biology (Alan Christensen, U. of Nebraska)
account of myiasis [invasion of living tissue by dipteran larvae] by M. scalaris in wounds of hospital patient (P.R. Hira et al, Kuwait U., Kuwait, courtesy of US National Institutes of Health)
images of all life stages; PDF doc compared to Drosophila melanogaster, and discussion of adult & larva locomotion and behavior (D.A. Harrison and R.L. Cooper, U. of Kentucky)