A source for information on flies
Bottle Fly Family
Bottle flies are
common, large flies known for their metallic blue or green color. These flies create a buzzing sound while flying
and are scavengers that feed on decaying meat or organic substances. They are transmitters of diseases and are
considered to be pests.A female bottle fly can lay up to 180 eggs at time, which are pale yellow or gray in color.
Resulting larvae measure between 10 and 14 millimeters in length and hatch within two the three days, depending on
temperature. Within two to 10 days, larvae seek pupation sites, from which they eventually emerge as adult flies.
Bottle flies breed in damp, organic matter such as dead animals.
Bottle flies are also
good pollinators. They often pollinate flowers with strong odors, such as pawpaws and goldenrod. When food sources
are diminished, bottle flies feed upon the nectar of these flowers in order to produce healthy
Bottles flies are typically
found outdoors. If a large number of bottles flies are found inside, an indoor breeding site may have been
established. To eliminate bottle flies, it is important to implement stringent sanitation measures, which include
cleaning garbage containers and making sure that the lids are seated tightly.
Green Bottle flies have striking, metallic, blue-green or golden coloration with
black markings. They also have black bristle-like hairs and three cross-grooves on the thorax. The wings are clear
with light brown veins, and the legs and antennae are black.
Medium-sized flies from 1/4-inch to 3/8-inch in
Shiny, metallic blue, green, or copper, depending
on the species.
Blow flies and bottle flies are important
scavengers in nature as they are one of the first insects to reach a dead animal. These flies are part of the
decomposition process that recycles nutrients back into the soil. The maggots of these flies may be used by
forensic entomologists to place the time of death in murder cases. They also breed in garbage containers,
dumpsters, and decaying vegetative matter (e.g., compost piles).
These flies are extremely common and can be found
one to a few at a time in homes or businesses during the warm summer months. They are attracted to buildings by
food odors and also warm/cool air currents emitting through cracks around doors and windows or through doors
propped open for ventilation purposes. The sudden appearance of dozens of blow flies or bottle flies within a
building signals a potential dead rodent, bird, or other animal in the wall, ceiling, attic, or crawl
space. They can generally be found anywhere that might contain dead
or rotting flesh: farms, slaughterhouses, fishing docks, dumpsters, rendering plants, dumpsters, etc. They can
also be found inhabiting animal feces and may deposit their eggs in the open wounds of living animals and even
Green bottle flies usually do not occur in large numbers inside buildings. If they do, it means that the
breeding site is probably indoors or in a place near an open vent, window, or doorway. Check chimneys, attics,
crawl spaces, vents, under floorboards, and above ceiling tiles for the source, which is often a dead rodent,
lizard, or other animal that has begun to decompose indoors.
A type of biotherapy exists (and is sometimes used, even today) known as Maggot Debridement Therapy (MDT). This
involves the intentional introduction of specially selected and tested, disinfected fly larvae (maggots) for
cleaning non-healing skin and soft-tissue wounds.
Medicinal maggots have three actions: 1) they debride (clean) wounds by dissolving the dead (necrotic),
infected tissue; 2) they disinfect the wound by killing bacteria; and 3) they stimulate wound
breeding sites of green bottle flies is the best method of non-chemical control. Proper sanitation is required,
and includes cleaning areas where garbage is stored, removal of dead and decomposing animals and fish, and
dispersal of decaying organic material, even compost piles.
Keeping green bottle flies from coming indoors involves properly fitted doors and windows which inhibit the
migration of these flying pests. Check for screens that are loose or torn, and inspect for areas where rodents
or birds may gain access to the building and possibly die while inside.
Be sure to seal all cracks around doors and windows, and install mesh screens behind any vents or other
openings that might allow the passage of flies and other winged insects into the dwelling. In most cases
involving bottle flies around homes, the problem is twofold: (1) flies are being attracted to the building
by trash containers or pet manure and (2) openings (e.g. doors) exist that are permitting flies to enter. To
minimize problems with flies, take the following steps:
- Throw trash away in trash cans in plastic
bags. Bags reduce odors associated with garbage and trash thus attracting fewer flies to the
- Locate trash receptacles as far from the
building as possible. Those flies that are attracted to the area will therefore be away from the back
- Keep doors and windows closed unless they
are equipped with tight-fitting screens.
- Ensure all edges of doors and windows have
tight weather-stripping. Flies can squeeze through amazingly small cracks.
If the presence of these flies is due to a dead
animal within the building, finding the location of the carcass and its removal is necessary, but is not easily