Overview
An exceedingly diverse family with large faunas in every region of the globe. It includes the ubiquitous housefly (
Musca domestica
(L.)), whose habits of feeding on excrement and entering houses make it a serious vector of enteric diseases; also the familiar pest, the Australian bushfly (
Musca vetustissima
Walk.). There are two blood-feeding species: the stable fly (
Stomoxys calcitrans
(L.)), which is a pest of humans and domestic animals, and the buffalo fly (
Haematobia exigua
(Meijere)), which can cause serious loss of condition in cattle. Species of
Atherigona
, too, are minor pests of cereal crops and species of
Hydrotaea
are tertiary blowflies of sheep.
The family has been well studied in Australia, with some 200 described species, although no doubt more await discovery. The subfamily Muscinae is well represented generically (12 genera), but, by comparison with other regions, poorly at the species level (only 29 species). On the other hand our nine genera of Phaoniinae account for about 100 species; principally in
Atherigona
(26 species, 10 endemic),
Dichaetomyia
(23 species, 18 endemic), and
Helina
(35 species, 32 endemic). Coenosiinae, too, are well represented by 60 species in 10 genera. Of the remaining subfamily, Mydaeinae, we have only some eight species in five genera.
Little is known of the vast majority of species, but it is thought that most larvae live in decaying organic matter, including faeces and carrion. However, some pest species of
Atherigona
have larvae that bore in the shoots of grasses and cereal crops; also, larvae of
Passeromyia
inhabit birds' nests, either as scavengers or ectoparasites, feeding on the blood and tissues of the nestlings. Adults of
Limnophora
are common on mud around ponds and streams where they may feed on the microfauna, while adults of many other Coenosiinae prey on small insects.
Description
The diversity of structure makes the family difficult to define. However, the combination of the bare meron and the sinuous vein Sc, plus the common (but not invariable) presence of a plumose antennal arista, lack of anepimeral bristles, and vein M that is straight or gently curved, serve to distinguish muscids from members of other families.
Distribution
Approximately 50% of Australian species are not known from elsewhere, but our most speciose genera,
Atherigona
,
Dichaetomyia
,
Helina
, and
Lispe
, have many close relatives in the Oriental Region and (especially) New Guinea and Oceania. Little is known of distributions within Australia; but some genera (e.g.
Dichaetomyia
) are mainly tropical, whereas species of
Helina
are found mostly in south-eastern Australia.