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House Fly

House Fly

Flies are not only a nuisance, but they can also be responsible for spreading numerous diseases. This is particularly true of House flies, which breed in organic waste such as manure, garbage, and animal carcasses. They frequent those places and then they come to rest on the surfaces in your space and on your food.

Below is a profile of the House Fly and ways to prevent this pest from infesting your home or property.

  • ¼” long
  • Dull gray with 4 dark stripes on thorax
  • 4th wing vein sharply angled
  • Adult house flies have sponging mouthparts that only allow them to eat liquids. Some solid foods can be liquefied with regurgitated saliva and then sponged up through the mouthparts.
  • While feeding, flies also defecate on their food.
  • Adults are attracted to a wide variety of food materials.
  • Larvae feed on decaying organic matter such as animal manure or droppings, wet garbage, piles of lawn clippings, decaying vegetables or fruits, soil contaminated with any of the above
  • Wherever house flies rest, they leave “fly specks”, light brown/cream-colors specks of saliva and excrement that are a strong attractant for other house flies.
  • Close to humans, in urban and rural areas.
  • Their favorite environments are dung heaps, garbage cans, and roadkill.
  • They also reproduce on rotted fruit and vegetables, old broth, boiled eggs, and even rubber.
  • For resting places during the day or night, house flies prefer corners, edges, and thin objects such as wires and strings, but can be found surfaces such as walls, ceilings, floors, the ground, plants, garbage cans, and fences.
Life Cycle
  • All flies have 4 distinct life stages: egg, larva (commonly called maggot), pupa, and adult.
  • An adult female house fly lays batches of 75 to 100 tiny, white, oval eggs in organic material suitable for larvae to feed on (see below).
  • In warm weather, the eggs can hatch in one day
  • When the maggots are ready to pupate, they move to the drier portions of the material they have been living in, or they may crawl quite a distance to pupate in loose material, under boards, stones, etc.
  • In warm weather, the house fly can grow from egg to adult in as little as 8 days.
  • Adult flies live from 15 to 25 days
  • Late summer and early fall
Favorable Conditions
  • Improperly stored food waste
  • Food residues in garbage cans and dumpsters produce many kinds of flies. Blow flies generally breed more abundantly in garbage cans than do house flies.
  • Rodent and other animal carcasses in traps, on glue boards, in walls and other inaccessible places will produce many hundreds of flies if left long enough.
  • Piles of warm, moist lawn clippings can be an important source of house flies in urban areas.
  • Poorly cared-for compost piles or bins can produce many kinds of flies.
  • Piles of manure can be a principle source of house flies in rural areas.
Health Concerns
  • Flies contaminate food, eating utensils, food preparation surfaces.
  • Flies are associated with many disease-causing organisms and their habits make them efficient mechanical vectors of these organisms.
Signs of an infestation
  • Presence of adult flies in and around the structure
  • Presence of maggots in organic decaying matter

What You Can Do To Prevent A House Fly Infestation

  • Use plastic liners in all waste receptacles that might collect food garbage; seal the plastic liners before placing in outside dumpsters or garbage cans.
  • Remove garbage containing food wastes from the building before nightfall or tie a knot in the plastic liner.
  • Keep waste receptacles and dumpsters clean.
  • Promptly fix drains or electric garbage disposal units that leak or drains that allow food waste to accumulate under sinks or floors.
  • Store food in the refrigerator, freezer, or cooler, or in insect-proof containers such as Tupperware or screw-top jars (screw-top jars are not insect-proof unless the lid has a rubber gasket).
  • Outdoors, pick up and remove fallen fruit as soon as possible.
  • Maintain compost piles properly, otherwise they can produce large numbers of flies.
  • Place dumpsters, garbage cans, and recycling containers away from outside doors to the building.
  • Remove pet feces as soon as possible, place in a sealed plastic bag, and then into a waste receptacle or dumpster.
  • The brown- to cream-colored fly specks found on walls and other surfaces where flies rest have a strong fly-attracting odor. They should be frequently cleaned off of surfaces with an odor-eliminating cleaner (a mild solution of borax or baking soda and water is effective).

To prevent fly entry:

  • Tightly screen all windows and doors
  • Weather-strip all windows and doors
  • Seal gaps around windows and doors
  • Screen air intake and exhaust vents
  • Equip doors with self-closing devices to prevent their being left open inadvertently
  • Install air curtains on doors that must remain open and cannot be screened. The air stream must have a velocity of 1,600 feet per second to be effective.
  • Sticky fly tape and/or fly swatters can eliminate a small number of flies indoors; however, fly paper may be considered unsightly.
  • Fly traps using ultraviolet light bulbs can be effective inside as a supplement to other measures. They must be used in areas where they are not competing with natural light. Follow the manufacturer's instructions carefully