Muscidae

The family Muscidae has worldwide distribution and includes many species that are common on carrion, excrement, and the products of decomposition. Muscidae have a close relationship with humans and are therefore considered synanthropic flies. This association has led to the inadvertent distribution of this family across the world, where it thrives in association with humans (McAlpine, 1981). In general, muscid flies tend to arrive after blowflies when colonizing a carcass and are therefore considered secondary colonizers (Byrd & Castner, 2010). Many of the species are associated with refuse and fecal matter and are common in rural areas, especially near large numbers of confined animals, such as poultry farms (Hewitt, 1912; McAlpine, 1981).

Musca domestica (Linnaeus)

Musca domestica is commonly known as the housefly and is a synanthropic species that has followed humans around the world. The adult is 6-9 mm in length, with an overall gray coloration. It is easily distinguished from other Muscidae by the sharp angle in its fourth long wing vein, and the presence of four black stripes on the dorsal thorax. It is commonly found indoors where it will search out food, refuse, feces, or carrion. The adult feeds on most anything with moisture and is particularly attracted to the products of decomposition. Larvae are often found in fecal matter in pastures or agricultural buildings, although they have the ability to develop on carrion. It is distributed throughout North America from Alaska and the northern regions of Canada down through the southern regions of the United States (James, 1947).

Musca autumnalis (DeGeer)

Musca autumnalis is commonly called the face-fly and is most often identified as a pest of cattle. The fly adults will feed on the body secretions of large animals, especially around the eyes and muzzle, andwill cause irritation to animals and humans in large numbers. It is native to the Old World and was introduced into North America during the 1940s. It is currently found through the mid- to northern United States and up into southern Canada, in areas with moderate summer temperatures. It is currently not found in Arizona, New Mexico, Louisiana, or Florida. The body resembles M. domestica but may be distinguished by a bright orange-yellow abdomen with a black median stripe in the males. The adults may be found aggregating indoors or under cover, and the larvae develop readily on cattle droppings. It will rarely infest carrion in the larval stage, but when present is attracted to fresh carrion and found in the first wave of decomposers (Huckett, 1975; McAlpine, 1981).

Hydrotaea (Ophyra) leucostoma (Wiedemann)

Hydrotaea leucostoma is a shining, blue-black species that is common around lavatories, slaughterhouses, and confined animals. It is widely distributed in North America and can be found north of Mexico up through the southern regions of Canada. The males have a characteristic hover behavior that is associated with the hoverflies. The larvae develop primarily in excrement but have been found exploiting carcasses in the late stages of decay. In the second and third instars the larvae are predaceous and will attack other larvae exploiting the same resources. The larvae will pupate deep in the soil and have been found burrowed three feet beneath the surface. Adults are abundant during warmer times of the year and are most common from June through October (Huckett, 1975; Smith, 1986).

Hydrotaea dentipes (Meade)

Hydrotaea dentipes is widely distributed in North America, ranging from the Gulf Coast north through southern Alaska and east into Newfoundland. Adults are of similar size and description to the housefly, approximately 8 mm long, but do not have the sharp vein in the fourth wing vein. The male is much darker than the female and has translucent dark wings. The female is lighter in coloration with clear wings. Adults are found on fecal matter and decaying fruit and are associated with latrines and offal. The larvae are found in compact and drying feces, carrion, and rotting fruit. The third instar larvae are predatory, feeding on other larvae within the same resource (Huckett, 1975).

Hydrotaea (Ophyra) aenescens (Wiedemann)

Hydrotaea aenescens, commonly known as the black dump fly or the American black dump fly, is common to warm areas of the New World. It is found throughout Canada, south through the United States, and into Mexico. It is a eusynanthropic species, frequenting dump sites and animal filth throughout the North American continent. In colder regions, it is able to withstand freezing temperatures by remaining on fermenting garbage. The adults are small, shiny black, and compact (Huckett, 1975).

Muscina stabulans (Fallen)

Muscina stabulans is a cosmopolitan species, widely distributed and especially common throughout the temperate regions of North America. It has been recorded in the north from Alaska to Newfoundland, and in the south from California to Georgia. It resembles Musca domestica, except without the sharply bent wing vein. The body is overall gray, and the hind tibia have a yellow coloration. Adults are found near human habitation and agricultural areas, especially poultry houses and stables. Adults will often move indoors and will feed on decaying matter of all types. The larvae become predaceous in the second and third instar and have been known to attack nestling birds. M. stabulans is often associated with buried carrion and has the ability to exploit decomposing matter below the soil surface (Huckett, 1975).

Fannia scalaris (Fabricius)

Fannia scalaris is primarily an outdoor species with cosmopolitan distribution. It has been recorded as far north as central Alaska, and as far south as Mexico (Huckett, 1975). If found indoors, it is associated with primitive conditions such as lavatories and cesspits and is therefore commonly known as the latrine fly. The larvae develop in semi-liquid masses of decomposing material and are associated with liquid in the abdominal cavity and the later stages of decay (Hewitt, 1912).

Fannia canicularis (Linnaeus)

Fannia canicularis is commonly known as the lesser housefly, and resembles Muscia domestica, except for the lack of a sharp bend in the long veins of the wings. The adults have an overall yellow coloration with a gray facial region, and an elongate brown-gray abdomen. The legs are dark brown with yellow joints. The adults appear to prefer cooler conditions than most Musca species, but is found all over the North American continent. The adults are common in rural areas near large accumulations of feces and are attracted to urine and other excrement-associated volatiles. It is common in the later stages of decay, and often associated with the second wave of decomposing insects (Grisales et al., 2012).