The scuttle fly

What is a scuttle fly? The scuttle fly, Megaselia scalaris, is a Dipteran fly in the family Phoridae named for the short, rapid bursts of running motion characteristic of adults. The species is alternatively referred to as the ‘humpbacked fly’ because of its hump-backed appearance (Figure 1), or the ‘coffin fly’ because of its ability to dig deep into the ground to reach buried carrion and penetrate closed containers such as coffins. It is predominantly a warm climate species, but has been found in all biogeographic regions in North America, Asia, Africa, and Europe. Scuttle flies are present in habitats ranging from urban buildings to tropical rainforests, and thrive in unsanitary conditions such as trash containers, public restrooms, sewer pipes, and litter boxes. M. scalaris is an omnivorous species, reportedly consuming a wider range of organic materials than any other insect. The larvae are capable of developing in living or decaying plant, animal, and fungal tissues, feces, milk, paint, and boot polish, and will consume almost anything that is, was, or came from a living organism. Larval development averages about seven days, with the subsequent puparial stage lasting approximately ten days; however, developmental time and percentage survival have been shown to decrease with increasing temperature from 21°C to 32°C. Scuttle fly adults grow to 2–3 mm in size, with females slightly larger than males. Females copulate soon after pupal emergence, and lay their eggs directly after copulation. Male fertility is purportedly limited to a short period after pupal emergence. M. scalaris is readily cultured in the laboratory, and its use as an experimental species in genetics, developmental biology, and drug and pollutant bioassay studies is increasing. Studies have compared the size, development, behavior, and genetics of M. scalaris to Quick guide Drosophila in particular. Although M. scalaris eggs and adult males are both similar in size to those of Drosophila melanogaster, the larvae and pupae of M. scalaris are much larger than those of similarly reared D. melanogaster. The life cycle of M. scalaris is significantly longer than that of D. melanogaster, with a much slower rate of maturation. External temperatures influence the fecundity, sex ratio, and longevity of M. scalaris.