House Fly

Overview:

This species of fly gets it’s name from being the most common fly found in and around homes, especially in the pre-automobile era and in rural areas. It is not only a nuisance pest but of greater concern is it’s potential as a carrier of disease organisms, having been found to harbor over 100 different pathogenic organisms. It can be found worldwide and is found throughout the United States.

Facts:

• Houseflies are a significant public health concern and are responsible for the spread of many filth related diseases.
• Adult flies can live for several days to 40 days or longer, depending on temperature, humidity, and the availability of food.

Identification:

• Adults are about 1/8 to 1/4 inch long with the female usually larger.
• Are dull gray in color.
• Face has two velvety stripes; each silver above and gold below.
• Thorax has 4 narrow black longitudinal stripes on the dorsum.
• The abdomen usually is pale especially at the base.
• Have sponging mouthparts.
• Mature larvae (maggots) are about 1/4 to 3/8 inches long, eyeless, legless and tapering towards the head from large rounded rear segment.
• The head of the larvae is represented by 1 pair of dark hooks.
• The larvae have a creamy color but with a "greasy" appearance.

Biology:

• Houseflies have a complete lifecycle: Egg - Larva - Pupa - Adult.
• The females will lay eggs singularly but in clusters of 75-150 in a variety of moist, rotting, fermenting organic matter including animal manure, dead animals, accumulated clippings, garbage, spilled animal feeds, and soil contaminated with any of the above.
• A female can lay more than 500 eggs in her lifetime.
• Eggs hatch within a day.  The young larvae burrow into the breeding medium and complete their development in 3 days to several weeks depending on the temperature and the quality food materials.
• Larvae will migrate to drier portions of the breeding medium to pupate for 3 days to 4 weeks before emerging as adults.
• Under optimum conditions, house flies can complete their lifecycles in less than 7 days.

Habits: 

• Flies are interested in food, heat, and sex.
• Can migrate up to 20 miles, but prefer to stay within 2 miles of the breeding site.
• Have a general appetite, feeding on food ranging from excrement to human food.
• Feed on liquids, but can eat solid food by liquefying it with regurgitated digestive tract fluids.
• Since house flies like it about 82 degrees Fahrenheit, they are attracted to insect light traps. They see the ultra violet light (humans can't see it) and are attracted to it for heat.
• During the day, houseflies will rest at a height of less than 5 feet.  At night they rest above that height.

Treatment:

1. Controlling house flies is very dependent on the situational and often a multi-faceted approach must be taken.
2. Like so many pests, sanitation is important.  Source reduction is the most important aspect in controlling houseflies because it eliminates larval breeding sites.  When successful, it reduces the need for pesticides.  If garbage cans are the issue, they should be emptied and thoroughly cleaned weekly.
3. Long term exclusionary methods can also be beneficial, but are not always practical nor the complete solution.  Consider insect-proof garbage containers, self closing doors, air curtains, positive air pressure, screening, caulking, or otherwise sealing up cracks, holes, etc. 
   Educated the occupants of the building to ensure doors and windows are not propped open making it easy for flies to enter.
4. Insect light traps are very effective, however there are many types, models, and manufacturers to choose from.  Choosing the appropriate model and location can mean the difference between a waste of money and an effective tool.
5. Insecticide treatments should be directed towards adult flies.  Watch where they rest and consider the proper material - aerosol, bait, or liquid residual.

FAQ's:

"WHY ARE FLIES SO DISGUSTING?"

As discussed earlier, flies eat liquids.  They do this through their sponging mouth parts.  In other words, they "sponge" the liquid and "suck" it up to eat.  In order to eat "solid" food, they regurgitate digestive fluid onto the solid food to make a slurry so they can then "sponge" and "suck" up the liquefied solid.
This can be of concern when you consider that the fly that is regurgitating and sponging and sucking on your cookie might have just come from doing the same on some animal feces in the back yard, thereby spreading germs.