With over 120,000 species of flies on Earth, flies have been scavengers of waste from the beginning of time. Filth-breeding flies are known to spread bacteria and diseases while other types of flies bite and burrow. Flies inspired two simple poems by the great American whimsical poet Ogden Nash. With strong roots in the south, and growing up in Georgia, Nash is sure to have seen plenty of flies!
Unbeknownst to most, flies pollinate many of the foods we enjoy today. Of the 150 different families of flies, 71 of them are known to sip nectar and transfer pollen. Without biting flies called midges, we would have no chocolate; midges are the chief pollinator of the cacao plant. Flies also aid in pollinating mangos, chili peppers, black pepper, carrots, and onions. Flies play an important role in food web as well. Flies are life-sustaining food for many animals including birds, lizards, and frogs.
And of course, flies have perhaps the most quintessential “dirty job,” poop and organic waste decomposer. Fly larvae consume rotting fruit, vegetables, and meat actually helping to clean our environment and proliferate the circle of life. In a murder investigation, blow flies are an important tool in helping detectives determine a time of death. Based upon the stage of life of the flies located on the body, a Forensic Entomologist can make a highly educated estimate as to the time of death. Given their proclivity for rotting meat, maggots (fly larvae) have been used to clean gangrenous and other wounds to prevent infection. The larvae eat the infected tissue, and in the process, cleans the wound with their antiseptic saliva. This allows new healthy tissue to grow. Maggot therapy has fallen out of favor due to the availability of antibiotics but may be experiencing a resurgence due to drug resistant bacteria.
Fly Diseases and Germs
Despite the benefits of the fly, they can not be allowed to remain unfettered. Flies spread e coli, salmonella, rotavirus, and hepatitis A. According to the World Health Organization, flies are known vectors of enteric infections such as dysentery, diarrhea, typhoid, cholera and certain parasitic worm infections. Trachoma, an infection spread by contact with flies, is responsible for blindness or vision impairment of nearly 2 million people worldwide. During the polio epidemic in the early 1900’s, flies were blamed because of the fecal to oral transmission of the disease. Skin infections such as yaws, cutaneous diphtheria, and leprosy are also associated with flies.
Flies and human diseases go hand in hand because flies readily land on human food and bacteria ridden waste such as decaying animals and fecal matter. While crawling and feeding on feces or dead animals, flies pick up disease causing organisms which stick to the hairs on their legs and bodies. They also ingest any bacterium present on their food. The bacteria ingested can remain active in the fly’s gut and will be present in his vomit and fecal matter. The mouthparts of flies are such that they can only consume liquid food; flies do not have teeth. When they land on their next meal, your burger perhaps, they regurgitate their stomach contents. This vomit breaks down and liquifies a portion of your burger which is then sucked up through its spongy mouthpart. While the fly is vomiting and sopping up a portion of your lunch, he may poop while doing it. The fly landing on your lunch has left you with three possible sources of contagion. Bacteria acquired from his last meal may have dropped off his legs or body onto your meal. Bacteria from his last meal may be left on your burger from his vomit or poop.
House flies are strong fliers but prefer to stay close to their breeding grounds. Under certain conditions they can fly 1-4 miles, but they are usually limited to 0.5 – 2 miles from their breeding grounds. Scientists disagree whether food should be thrown away if landed on by a single fly. Immune compromised individuals should be more conscious than the healthy, but the risk is very real that the fly who just landed on your burger was standing in dog poop minutes before.
Life Cycle of a House Fly
To better understand flies and how to get rid of them, we have to understand their life cycle. The house fly has a complete metamorphosis with a distinct egg, larvae (maggots), pupae, and adult stage. In optimal conditions, the house fly has immense breeding potential; a generation can be produced in 2 weeks. However, in cooler conditions the life cycle may take a few months to complete. In temperate regions there may be 10 generations of flies living together at a time, whereas in the warmer tropical and sub-tropical regions of South Florida as many as 20 generations may occur at the same time.
The female house fly lays eggs in nearly any warm organic material, from dog or other animal feces, to garbage, or grass clipping and a compost pile. She lays eggs in clusters of 75-100 and lays about 500 eggs in a span of 3 or 4 days. Within 24 hours, the eggs hatch and larvae or maggots emerge. The maggots immediately begin feeding on the filth into which they were born. Manure and trash cans provide excellent and abundant nutrition for maggots. In the peak of summer in the south, with temperatures in the 90℉, flies only stay in the pupal stage for 4-13 days. At cooler temperatures house fly maggots take between 14-30 days to mature to the next stage.
When the maggots are fully developed and well nourished, they crawl away from the moist environment in which they have been feeding and pupate. The fly pupae are similar to cocoons. The fly becomes encased in a hard shell which protects him as he matures into an adult. As the pupae matures and ages, the casing becomes darker, from yellow to orange, and ultimately to almost black. In prime fly season, this development only takes 2-6 days but this can vary greatly. At cooler temperatures, they may remain in the pupal stage for 2-3 weeks. The adult fly emerges, hammering through the pupal case. After their first meal as adults, flies are ready to mate. A protein meal is required to produce eggs, but a female fly can begin to deposit eggs 4-20 days after copulation. Most flies live for 2-3 weeks, but sometimes they live up to 2 months.
With rapid reproduction rates such as this, it is no wonder that flies are rampant at Fourth of July picnics in the south. Large populations rapidly build up under optimal conditions. Controlling flies often requires a multi-layer approach and thoughtful consideration of breaking the life cycle of the fly.
Fly Integrated Pest Management – Sanitation and Fly Prevention
Integrated Pest Management, or IPM, is the concept that in addition to pesticides, mechanical, physical, cultural, and biological controls are used to control pests. The control efforts are constantly monitored and adjusted according to the success of the treatments. Because of the strong link between the presence of flies and their breeding grounds, IPM lends itself nicely to fly control.
The key to managing all filth flies is sanitation. Filth flies large and small depend upon accumulations of organic matter to reproduce. Typical fly breeding grounds include garbage and waste from homes and restaurants, heaps of accumulated animal feces, sewage, accumulated plant material, or any other organic material. Dumpsters at a restaurant should be kept clean, emptied regularly, and kept as far away from buildings as possible. Manure at a farm or stables should be removed promptly. Floor and sink drains should be kept clean and gunk free. Wherever the organic matter accumulation is, it must be removed or mitigated for effective fly control. Without sanitation, insecticidal control will be ineffective.
Physical methods of fly control include anything used to kill the fly directly. A well placed slap from the bottom of your shoe or a fly swatter is considered physical fly control. Fly traps, lights, and electrical fly zappers are also commonly placed in areas of known fly activity. These physical methods of fly control should be used in conjunction with sanitation efforts. For centuries people have used barriers to keep food and themselves separated from disease spreading flies. Nets over bedding, door screens, fly curtains, and mesh coverings over food all help to mitigate the harmful effects of flies.
Once sanitation and physical controls are implemented, flies and their breeding sites can be attacked with pesticides as well. Fly baits are an effective and convenient method of reducing adult flies. Depending on the location and situation, fly resting spots may be treated with a residual insecticide. Including an IGR or Insect Growth Regulator with your chemical treatment, you can break the fly life cycle and prevent the flies from reproducing.
Fly Control Products and Methods
Consistent with the tenants of a good IPM fly program, there are many tools in the Pest Management Professional’s toolbelt for getting rid of flies. As stated above, the first and most important step is sanitation. Without proper trash handling procedures or manure removal, no amount of spraying or zapping the flies will eliminate the problem. Fly control methods and products are as diverse as many of our homes and businesses.
Fly Bait
When an area cannot completely eliminate the source of fly breeding, such as on a farm, kennel, or near a compost pile, baiting for flies is an excellent source of relief. An insecticide bait is a formulation that combines a food attractant with a pesticide. The target pest smells the food and consumes a toxic dose of the pesticide. Because there is such a small amount of active ingredient, pest control baits are usually considered more environmentally friendly than sprays.
Fly baits have various attractants, ranging from simple sugars to fermented yeast, animal proteins, eggs, ammonium carbonate, ammonium sulfate, fish meal, syrups, and malt. As you can imagine, some of these fly baits are quite pungent. However, the stronger the odor, the more flies it will attract and thus kill. Fly baits come in various formulations; liquid baits dispensers, dry scatter baits, granular bait placed in a station, aerosol sprays, or a liquid paint on or spray application. As with any insecticide, keep away from children and non-target animals. If you are treating an area with horses, chickens, or cows or other animals read the label on your chosen fly product carefully, but in general we recommend always placing fly bait inside of a bait station and out of reach of non-target animals and children.
A properly applied fly bait product can be highly effective. I have seen flies avoid a freshly grilled cheeseburger in favor of the fly bait. Place your bait in areas where flies congregate, but ideally away from people and animals. If you are hosting a BBQ or party, do not place the bait on the table or eating surface, but somewhere close enough to lure them away from the hot dogs. Many of these baits are very fast acting; it is highly satisfying to watch the fly drop after landing on the area that you just sprayed with bait. Granular baits placed in a bait station can offer long-term killing of adult flies, but the bait stations need to be checked and refilled regularly. A very popular fly bait formulation is a paint on fly bait. This viscous bait can be painted onto walls, posts, ceiling rafters, or another material which can then be hung or suspended in fly prone areas. The bait sticks to the surface that was “painted”, and the bait can be active for up to 6 weeks.
Fly baits can be used during a backyard special event, or they can be more regularly applied to fly prone areas. Either way, the various formulation and specializations ensure there is an effective fly product for your needs.
Fly Insecticide Sprays
Fly control is not as simple as hosing the perimeter of your home with spray and hoping for the best. Insecticidal sprays can be a component of your fly control program, but because flies reproduce so quickly, without sanitation to eliminate the breeding grounds, sprays alone will not wipe out flies from your property. Another reason we cannot rely solely on spraying, is that flies are becoming increasingly resistant to many insecticides. Moreover, flies tend to be more problematic in stables and barns, anywhere animals defecate. Always use caution with chemicals around barnyard animals; read the label and follow the instructions precisely.
It can be useful to treat fly resting areas with a residual pesticide. A residual pesticide is one that remains active weeks or some on some products months after it is applied. The residual length depends upon the specific product, the formulation, and the environment to which it is applied. Spot treatments in areas of high fly activity is the most efficient. Fly resting areas are often near their breeding location or near windows emitting light. You may find them resting under the eaves or in the rafters of the stable or on the walls of a carport or porch. Always follow the label when applying pesticide.
Flies in the Sink Drain
If you are battling small flies such as fruit flies or phorid flies a drain treatment with a product that eats the accumulation of organic matter will do the trick. These small flies are likely breeding in the organic scum that has accumulated in your kitchen sink drain or garbage disposal. Products containing enzymes that eat this scum are highly effective at removing the breeding ground for these small flies, thus eliminating the problem. Many of these enzymatic products have a pleasant citrus smell and are highly effective. These products are formulated as either a thick viscous liquid that coats the sides of the drain, a foaming aerosol that clings to the sides of the drain, or a foaming concentrate which requires special equipment to create the foaming action.
How long it takes to get rid of the drain flies depends upon the amount of buildup in your drains. The drain gel or drain foam should be used every day after the sink has been used for the day, usually at bed time or closing time. It will take at least a week to adequately clean the drain so that the flies cannot reproduce in that location. Restaurant and commercial spaces with floor drains should regularly treat their drains to prevent the buildup that these small flies breed in.
Flies, or any insect breeding in your drains, are particularly challenging because it is never appropriate to pour pesticides down your drain. The product described above is not a pesticide, it is a blend of beneficial microbes and enzymes. However, it can be mixed with another powerful tool called an IGR or Insect Growth Regulator. IGRs prevent immature drain flies from turning into adults capable of reproduction.
By adding an IGR into your attack on flies breeding in your drain, the time it takes to see results and gain control is lessened. Be sure to check the label on the IGR you choose to make sure it is labeled for application to drains. If you choose a liquid concentrate IGR you will need a foaming agent and specialized equipment to create the foam. Insect Growth Regulators are also available in convenient aerosol formulations which does not require mixing or any specialized equipment. The IGR foam or aerosol will coat and cling to all areas of the drain and pipes to disable to reproductive capacity of all the drain fly larvae it touches.
Fly Traps
Fly traps are insufficient on their own to solve a fly problem, but they can eliminate a handful of buzzing adults. Adult flies typically make up 10% or less of the fly population. Traps can help, but remember that 90% of the flies are located in the breeding sites. Most fly traps contain a liquid attractant and some type of plastic or glass containment system. Commercially available fly traps are often plastic pouches that can be hung from the rafters of barns or trees. They fill up with adult flies who drown in the liquid. Once filled with dead flies and liquid, many people find these fly traps rather revolting to throw away and change. They are known to leak and drip fly laden juice, stink, and are unsightly especially if used in a commercial setting. Often dead flies and maggots can be seen squirming around inside the bag. While technically speaking, maggots inside the bag is a good thing as they will not mature into annoying adult flies, the bag traps tend to smell bad and are irritating to deal with.
There are many ways to make a home-made fly trap as well. Soda bottle traps and mason jar traps are popular versions for home-made fly traps.
If fruit flies are swarming in your kitchen, a simple dish of apple cider vinegar and a drop of dish soap is a popular home remedy. This homemade trap will capture and kill some of the flies, but you will not catch them all. Without cleaning the breeding sites, these pesky flies will not be eliminated with traps. Pour apple cider vinegar in a small dish and cover with plastic wrap. Cut a slit in the plastic wrap to ensure the flies come in and they can’t escape. Flies are attracted to any fermented organic material (beer or wine) and will come to the dish expecting to land on its surface. The soap breaks the surface tension causing the fruit fly to drown in the bowl of vinegar. Many commercially available fruit fly traps are prefilled with the solution and the whole unit is self-contained and disposable. You do not have to look at the dead fruit flies or handle them in any way.
Fly traps also utilize adhesion to trap flies. The most popular trap of this kind is a metallic gold column which can be hung from windows, garages, homes, offices, stables, and near dumpsters. The reflective gold shimmers and attracts flies, and pheromones are often included to attract the flies. Once they land on the gold stick, the flies become stuck onto the surface and can not get off. These fly traps contain no pesticides, insecticides, vapors, or foul odors.
Fly paper or fly sticky tape suspended from the ceiling area are another non insecticidal method of physical fly control. Fly ribbon or fly paper often some sort of sugary attractant on them and can be used indoors or outdoors. Flies come for the sugar and stay because they get stuck on the very sticky surface of the paper. Once the surface of your fly tape is covered in flies, you simply remove the tape, throw it in the trash can, and replace if needed.
Fly Lights and Electronic Fly Zappers
Fly lights are a worthwhile investment for businesses that need continual fly control. Think of your neighborhood grocery store. It has large doors that open and closes often throughout the day, both in the front and the back receiving areas. By necessity, your grocery store has large dumpsters and is often near restaurants and other businesses; an occasional fly is bound to come through the door. Excellent fly control is necessary to earn your business as flies buzzing around the deli or produce department is simply unacceptable. Businesses often incorporate fly lights into their fly control protocols to capture and kill any fly that happens to make it into the store.
There are two styles of fly lights; they both utilize UV light to attract the fly to its death. Once drawn to the light, the fly is either electrocuted or becomes stuck to a removable glue card. To remain effective fly lights must be regularly maintained; the light bulbs must be changed out annually, and the glue cards must be changed monthly. Fly glue boards should be on a regular rotation to be checked at least once a week. A dusty/dirty glue board will not catch any flies. Even if the light bulbs have not burned out, they should be changed every 12 months. As they run, the UV rays become weaker and will not attract flies at its maximum capacity. Selecting the most appropriate location is critical in the success of your fly light. Install a fly light away from sensitive areas to help draw flies away from customers and food. The sticky cards are excellent tools for evaluating the effectiveness of your fly control program. Knowing your dates, you can count the number of flies stuck to the glue card, thus measure and evaluate your fly control procedures.
Fly lights range from small residential options to large commercial applications. A very popular home-owner option simply plugs into an electrical outlet and is no larger than a large night light. It can run continuously and the house flies or fruit flies it catches are hidden from view.
Commercial use of fly lights often requires a more substantial product than the home-owner model. Many “front of the house” fly lights are cleverly disguised to look like a decorative sconce or an ordinary light fixture. The customers in a restaurant or store have no idea that flies are stuck to the glue card behind the lighting fixture. More utilitarian fly lights are used in restaurant kitchens and areas that the public does not access. These often have a larger fly catching surface and are more accessible to the flies. Fly lights utilizing sticky cards are more often used in food settings and public places.
Fly zappers are commonly used in warehouses where receiving doors remain open for long periods of time. In food prep areas and public areas of a business, we recommend glue trap fly lights as opposed to zappers. When flies are electrocuted, they immediately drop and sometimes break. The last thing your business needs is to serve a fly leg in the salad!
Fly lights are the last defense product in your fight against flies. Fly lights cannot solve a fly problem on their own, but with proper sanitation, excluding the flies using screens and barriers, and killing them with baits and insecticides, fly lights can effectively take care of the few fly survivors.
How to Prevent a Fly Infestation
In a normal residential situation, the most effective fly prevention tool is sanitation. Without reduction or elimination of the breeding grounds, filth flies will persist and become a chronic problem. Normal household sanitation involves addressing all of the following issues:
Garbage – In warm climates, garbage should be collected twice per week. This ensures that the fly life cycle will be broken. If you happen to miss a trash collection, make sure the lid is tightly secured to the can. In addition, garbage cans should regularly be cleaned. The sludge, or drippings from your trash bags not only stink, they are a filth breeding fly heaven. Attention should be paid to your indoor trash can as well. Get into the habit of wiping it down weekly to eliminate organic matter or rotting fruits and vegetables.
Pets – As you know, flies are attracted to poop. It is the perfect place to lay their eggs and they larvae will emerge into a nutrient rich environment. If you have pets who roam the yard and go when and where they please, you should pick up and remove the poop. You can use the disposable poop bags or you can install a septic style dog waste disposal system. Especially in the summer months, to adequately prevent flies, pet waste should be picked up daily.
Screens/Barriers – Keep all the screens on your home in good repair. If a fly wants access to your home or porch, he only needs to find a small tear or slit in a screen. If you regularly eat outdoors, consider purchasing mesh food screens. They come in all sizes and many fold down like a tent or umbrella for easy storage when they are not in use.
Moisture – Flies require moisture to complete their life cycle. Flies tend to lay their eggs in moist areas with high organic content. If you have a dripping spigot, and your dog poops in the moist soil around the spigot, it will be highly attractive to flies. That dripping spigot moistening soil around decomposing leaf litter, will exacerbate fly breeding in that area.
While not fly prevention, per se, fly baiting in preparation for a party or back yard event can be highly effective. The most convenient fly bait product is formulated as a ready to use aerosol. Prior to the BBQ, spray the fly bait on or near the trash can and lid that will be used, inside recycling bins, and any other labeled surface. Try to place the bait away from food and guests in order to lure the flies away as well.
Of course, there are some industries that are inherently prone to flies. Sanitation for fly control looks different on a farm than it does in a suburban neighborhood. Even in these locations, elimination of breeding sites is still the key to prevention and control. Flies requires breeding material, moisture, and warmth to complete their life cycle. In barns or stables, procedures for promptly dealing with manure are mandatory. Maintaining adequate drainage around manure, hay or straw, and spilled feed is necessary. Fans directing air outwards and down help to keep flies from entering the barn or stable. Monitoring the abundance of flies helps you to assess your fly control program. Sticky paper or ribbon not only catches flies, by counting and keeping track of the flies, you will know when changes to your fly control protocols should be implemented.
Commercial Fly Control
While no one wants flies in their home, they are often a passing inconvenience. Fly infestations at a business, whether a restaurant, bar, or shop can negatively impact your customers’ experience, thus your rate of return customers. Flies start costing you money when your yelp profile is filled with people who loved the meal but disgusted by the flies on the patio. Your business’ reputation may depend upon your ability to get rid of flies! Restaurant owners and managers should proactively work to reduce or eliminate flies from your premises. Post Covid-19, we are more informed on the spread of germs and bacteria, and we are more inclined to choose outdoor seating if it is offered. This combination collides to cause restaurant owners and managers greater need to control filth breeding flies both large and small. Employee training and follow through in proper handling of trash is imperative if customers are to enjoy your socially distanced patio.
All of the facets of Integrated Pest Management should be utilized to ensure a safe enjoyable customer experience. A Pest Management Professional can inspect your kitchen, dining room, patio, and surrounding areas and create a protocol to ensure a fly free experience. It will likely include drain treatments, installation of fly lights and a maintenance program for them, and insecticidal treatments of fly resting spots. You may need to invest in regular cleaning and sanitization of your dumpsters, recycle bins, compactors, and even the pads underneath. If the dumpster pad or enclosure has inches of organic grime, flies will persist. Effective training and management of employees in sanitation practices and procedures is crucial to the success of fly elimination efforts in a commercial setting.
Flies and Indoor Rodent Infestations
Flies are often the first decomposer that arrives when an animal dies. In the woods, this is fine and well, in your attic, it creates a potential horror show. We never recommend using rat poison indoors. When you toss a handful of rat bait into your attic, rats, or other mammals such as squirrels or raccoons, will eat the bait and die in the far reaches of the attic or even inside of a wall void. These animals are often very difficult and sometimes impossible to reach and remove. Blow flies can find a dead animal within 20 minutes of its death. Blow flies lay their eggs on this decomposing carcass, and the larvae emerge about 24 hours later to feed on the dead animal. Now, you not only have the stink of death emanating in your home, but the blow fly life cycle has also begun. Unless that animal carcass is removed, the metamorphosis will complete, and adult blow flies will invade your home. In warm conditions, the blow fly life cycle takes anywhere between 9-21 days to go from egg to adult. Adult blowflies are larger than typical house flies and have an audible buzz when they fly near you. They are blue and green metallic in color and highly attracted to the light of your home. If you suspect rats, mice, raccoons, or squirrels may be in your attic or basement, trust a competent Pest Management Professional to eliminate the problem. An invasion of blow flies into your living room is no laughing matter.
Filth-Breeding Fly Control
With over 120,000 species of flies, entomologists categorize flies by their behaviors and physical characteristics. This equates to 3 main headings of flies, nuisance non-biting filth breeding flies, nuisance biting filth breeding flies, and small flies. The most common flies dealt with in modern America, are non-biting filth breeding flies. This includes the common house fly, blow/bottle fly, soldier fly, and the flesh fly. With proper sanitation and a thorough understanding of how and where they proliferate, filth breeding flies can be controlled, even in difficult commercial situations.
House Fly Control
Where people congregate, house flies can be found. Adult house flies are usually 1/8” to ¼” in length. They are dull grey in color and have 4 black stripes on the middle section of their bodies (thorax). They have a single pair of wings, and large red compound eyes. The compound eyes consist of many ommatidia, which acts as visual receptors. Each of these receptors creates a single image, and when combined with the other images creates a visual mosaic picture. The compound eye of the house fly may contain as many as 28,000 ommatidia. Compound eyes allow house flies to be highly reactive to movement. Compound eyes are the reason it is extremely difficult to swat a house fly.
For a creature that is attracted to manure and animal carcasses, house flies meticulously groom themselves. They utilize their forelegs to remove any debris from their eyes and their wings. Even the smallest amount of food on their wings, impairs flight. Any insect with 2 wings belongs to the order Diptera, and these are often referred to as true flies. The house fly is a true fly with 2 wings. However, beneath their main wings, the house fly has drum-stick shaped organ called halteres. As the fly flaps his wings at rates of 200-300 times per second, the halteres flap and allow them to maintain balance and stabilization while in the air. House flies have the ability perform complicated flight patterns such as zig-zags, spirals, and they can even fly backwards. House flies fly at an average speed of 4.5 miles per hour. With compound eyes and their strong ability to fly, it’s no wonder it’s hard to swat a fly!
House flies undergo complete metamorphosis, meaning they transition from egg to larvae to pupae to adult. The time it takes to complete this life cycle depends upon the temperature and availability of food. In ideal conditions of Florida or summer in Georgia, it may only take 6-10 days to go from egg to adult house fly. Like other filth breeding flies, adult house flies deposit their eggs in any type of warm organic material. Manure is ideal but rotting grass clippings or garbage provides a suitable fly breeding environment. Once the eggs hatch, the larvae (maggots) eat the filth into which they were born. Gaining their nutrition from the fecal matter, garbage, or rotting leaf litter, the larvae may eat for 4-6 days before they pupate. Fly pupae are similar to the cocoon of a butterfly. The fly pupae are enveloped in a hard shell casing and protected as they develop into adult flies. In warm conditions, the pupal stage may last only 3 days. When they emerge as adults, the males are sexually mature, but the female needs a protein meal before she can lay eggs. Most adult house flies live for about 30 days, and on average female house flies lay 500 eggs in their lifetime.
House flies are capable fliers, but they tend to remain close to the breeding site. If the breeding site is allowed to fester on your property, fly populations explode quickly. Eliminating breeding sites is the best long term solution to get rid of the common house fly. This may mean, picking up dog poop from your yard, ensuring the garbage goes to the curb twice a week as scheduled, or covering your compost pile. Sometimes, you can not eliminate the source of the flies. If your neighbor has a horse, you are probably not willing to go muck out the stall for them! However, even in barns, poultry houses, dairies, and food processing plants house flies can be controlled.
If you can not eliminate the breeding source, house flies can be controlled with measures such as fly bait, residual pesticide treatments, fly lights, and fly sticky tape. In these difficult locations, your Pest Control Professional can recommend a fly reduction protocol and methods of assessing the success of this protocol. By incorporating multiple methods of control, house flies will less successfully reproduce, and the ones that do will be killed by fly bait, insecticide placed on their resting places, or stuck in a trap or on a glue board somewhere.
Blow or Bottle Fly Control
There are many different species of bottle flies and blow flies that are found in and around homes. These flies are noticeably larger than the common house fly and are often metallic in color, boasting blue, green, or bronze shimmer. Because of their larger size, there is often a distinctive audible buzzing sound when a blow or bottle fly is in your immediate vicinity. Blow flies derive their name from the old English phrase used to describe meat that flies had laid their eggs on. This meat was said to be fly blown. This is an apt name for these flies, as they are often the first to arrive at a carcass.
Blow flies can descend upon a dead body within minutes. Like other flies, blow or bottle flies, mature through the process of metamorphosis. Under certain quantifiable conditions, the life cycle of blow flies and their larvae (maggots) is reliable and predictable. When a homicide detective is creating a timeline, the time of death is extremely important. By examining the blow fly maggots present on a body, a forensic entomologist can work backwards and with great accuracy predict the time of death.
Blow and bottle flies usually breed in decaying carcasses, meat scraps, animal excrement, and decaying animal matter. From egg to adult the life cycle takes between 9 – 21 days. A single female blow fly can lay up to 2,000 eggs in her lifetime. Prolific egg laying and a rapid life cycle can create an abundance of blow or bottle flies unless control measures are taken. Because blow flies move readily between human habitats and fecal matter and carcasses, their capacity for transmitting disease and germs is high.
Controlling blow or bottle flies requires a blending of cultural and chemical controls. Cultural control involves anything that modifies the environment to reduce or prevent pests. The most effective form of cultural control is removing and burying any dead animal remains on your property. Animal carcasses should be buried at least 12” deep and covered promptly. Garbage cans should be cleaned regularly to reduce the blow fly’s attraction to the area. Blow flies are strong fliers, even if the carcass is not within your authority to remove, you may still deal with the blow flies. Other forms of effective cultural control include keeping screens and doors in proper working order, sticky traps and light traps can capture the blow flies that do make it inside. Because of their strong preference for rotting meat, fly baits that use a sugar attractant are ineffective against blow flies. However, there are fly baits that will attract and kill adult blow flies. If you do use fly bait, remember to place the bait so as not to draw the flies towards your home or patio. If blow flies are a chronic problem, residual insecticides may be applied per the label on areas where flies tend to land and rest.
As Professional Pest Control Operators, we are often called in to a blow fly infestation after a Do-It-Yourself rodent or nuisance wildlife attempt. By tossing rodent bait into your attic or in the crawl space you not only invite horrific odor of decomposing rat, you also invite blow flies. As stated above, if there a dead animal, blow flies will find it and lay eggs. The larvae/maggots will partake in the carcass then pupate. Unless the carcass is removed, adult blow flies will emerge and be drawn to the light in your home. Should you come home one afternoon to hundreds of large blue and green flies buzzing at your windows and lights, you likely have had a carcass nearby for a little over a week. In this situation, think rapid cultural control, like a fly swatter! Sometimes people have luck luring the blow flies out the door by turning off the house lights and turning on porch or even car lights. If you are lucky, they will fly toward the light and right out the front door. Unfortunately, this is a scenario that is likely to play out day after day until the life cycle of all the eggs laid has come to fruition.
Soldier Fly
Soldier flies are very different in appearance from the other filth breeding non-biting flies. They look more like a mud-dauber wasp than the house fly. They are approximately 1” in length is usually black in color. Depending on the species, the soldier fly may be metallic green or blue, and his antennae has a joint that bends like an elbow.
The adult soldier fly is rarely seen. It is usually the larval and pupae stages that are noticed. Where other filth-breeding fly larvae look like tiny white worms, the soldier fly larvae are brown, flat, and torpedo shaped. They grow to be over an inch in length. These distinctive soldier fly larvae are almost always concentrated in and around fecal matter and garbage. Inside your home, you may see the soldier fly larvae in bathrooms near the toilet. Their presence indoors may indicate an issue with the septic or sewer line. Outdoors, the soldier fly larvae will almost always be found around dumpsters, garbage cans, or compost piles.
As with all filth-breeding flies, sanitation is the key to control. In and around a restaurant or other commercial dumpster, regular sanitation and cleaning the dumpster is necessary. Products that use enzymes to “eat” the organic matter accumulation are helpful to reduce soldier fly breeding. Soldier fly larvae are especially prone to be present in very moist environments with later stages of decomposition present.
Killing adult soldier flies, if found, will of course reduce the infestation, but you simply must eliminate the breeding source. After a dumpster has been emptied and thoroughly disinfected and cleaned, an application with a residual pesticide may help eliminate the adults. However, if the dumpster is permitted to return to its previous state of grime, soldier flies and their larvae will return. Employees should be continually trained on proper trash disposal procedures and the repercussions of an unkept trash area.
Flesh Fly
Flesh flies are a medium sized fly usually with 3 dark stripes on his abdomen and a blotchy checkerboard appearance on his thorax. Flesh flies are slightly larger than house flies and with distinguishable markings, however the 2 species are often confused. Many of the flesh fly species have a “red butt” at the rear of their abdomen that helps distinguish them from house flies. Appropriately named, the flesh fly often deposits her eggs in flesh wounds and animal carcasses. Similar to the blow or bottle fly, the flesh fly is one of the first decomposers to find a carcass or a fatally wounded animal.
Unlike many other flies, flesh flies are ovoviviparous, meaning the female flesh fly holds her eggs inside her “uterus” until they are ready to hatch and a proper host has been found. She then deposits live larvae directly onto the food the larvae will be eating. These larvae immediately begin to eat the flesh onto which they were placed. These flesh fly maggots sometimes even burrow into the carcass or wound. They feed for approximately one week then wander away and pupate. In ideal temperature conditions, flesh flies will remain protected in their pupal casing for approximately 10 days and then emerge as adults. The life cycle of the flesh fly is usually completed in 14-21 days, but they have the unique ability to overwinter in the pupal phase. This diapause or “hibernation” is triggered by environmental changes such as temperature, humidity, or light availability. During this diapause, flesh fly pupae slow down their processes until favorable conditions return.
Flesh flies are rarely an ongoing problem in residential suburban neighborhoods and are not considered a major pest species. Generally, a fly swatter is enough to rid yourself of the occasional flesh fly. However, the presence of flesh flies may indicate carrion or a carcass nearby. If an animal has died within your attic, walls, or crawlspace, unless you remove it and clean and sanitize the area, you will likely deal with flesh flies.
However, flesh flies can be chronic problem in meat processing plants or dumpsters where raw meat is tossed. Flesh flies may breed underneath a dumpster if organic meat matter has accumulated or if there is a dead rodent under the dumpster. In barns and stables, animal wounds should be inspected, cleaned, and treated appropriately to prevent a flesh fly infestation. Flesh fly prevention and sanitation is the most effective control. Whether a meat processing plant, or a restaurant you probably already have fly lights and fly chemical treatment procedures. Flesh flies will be affected by these processes designed for other types of flies, however proper removal and disposal of animal carcasses and remains is paramount to keeping flesh flies away.
Nuisance Nonbiting Fly Control
Of the 120,000 or so species of flies in the world, there is a small handful of them are physically annoy or bite humans. Cluster flies and face flies do not bite, but they are an annoyance to anyone trying to work or play outdoors. Not only a nuisance to humans, these flies land on cattle and horses and make them uncomfortable. These flies do not breed indoors, but they may overwinter indoors. Both cluster flies and face flies are rarely found in very hot climates such as South and Central Florida, but can be found in Georgia and north.
Cluster Fly
The cluster fly, sometimes called the attic fly, is a little larger than a house fly. The cluster fly is dark grey in color with three black bars and short golden hairs on its thorax. The cluster fly moves more slowly than the house fly, and is most often seen in large numbers clustered near windows of seldom used rooms in the late fall early winter and again in the early spring. The cluster flies lays her eggs in the soil which hatch in about three days. Cluster fly larvae are parasites or earthworms. The maggots penetrate earthworms and feed on them for between 2 -3 weeks. Cluster fly larvae then proceed to a pupal phase before emerging as adults.
Adult cluster flies usually live outside and feed on flowers and ripe fruit. However, in late summer or early fall they look for warm places to overwinter. Cluster flies enter your home through the smallest of holes or cracks in the walls, windows, and doors. Large accumulations of cluster flies huddle together in attics, wall voids, and false ceilings. They are usually found in the higher regions of homes and structures, but they have been known to cluster during the winter months in dark corners of closets underneath clothing, beneath curtains, and behind pictures on the wall. With the warmth of spring, they are triggered to emerge from their hiding places. In trying to get outdoors, they are often found in the inside near widows. They sluggishly crawl around trying to escape your home and are often smashed by rolling blinds and other inherent dangers in your house.
The most effective defense against cluster flies is sealing off their entrance avenues. However, as they can fit through extraordinarily tiny holes, this is very hard to do. To reduce the number of cluster flies that enter for the winter, patch, seal, or caulk every hole and crack you can find. Exclusion efforts should be performed in the summer before cluster flies begin to enter the structure. Even the most thorough exclusion job may not keep all cluster flies from gaining entry to your home. Consider using a good residual pesticide to kill the cluster flies before they penetrate your home. Follow the label carefully and apply the insecticide to windows, doors, soffits, eaves, and any other areas susceptible to cluster fly admission. If the label allows, you may also spray cluster fly resting places. This will knock the cluster flies down both before and while they attempt their entry to your home. Insecticide for cluster fly prevention should be utilized in mid to late summer before they get into your home.
Once cluster flies are inside your home, mechanical controls are the way to eliminate them. Your vacuum cleaner is an effective way to remove the cluster flies as they attempt to find their way outside. Aerosol contact sprays can be used for immediate relief. If you use a fly swatter on cluster flies, they often leave a greasy residue and a slight odor that some people compare to buckwheat honey when crushed. They have strong attraction to light, which is what draws them to your living area when winter is over. However, you can use this biological tendency to your advantage. In severe situations, insect fly lights can be placed in the attic or false ceiling. As the cluster flies awaken, they will be drawn to the light and stuck to the glue board. Great care should be used in the placement of insect lights so as not to cause a fire hazard. The glue boards should be checked regularly, as a full or dirty glue board catches no flies.
Face Fly
Face flies are another common fly that is considered a nuisance but does not bite. However, they do overwinter in structures and emerge in the spring as a pest. Face flies look very similar to a house fly and can only be visually distinguished by an entomologist. The identification method centers around a highly specific tuft of bristles on the thorax. However, the habits and behaviors or face flies and house flies are very different.
Face flies are most problematic for cattle as adult face flies feed on excretions from the cow’s nose, eyes, and mouth. There is a belief that face flies may spread pink eye to cattle. The life cycle of the face fly takes approximately 18 days in summertime temperatures. Face fly eggs only develop properly on cow manure; therefore, the exposure of this pest is somewhat limited to farmhouses and areas where cattle are abundant. Like cluster flies, face flies seek shelter and warmth in the late fall. They enter homes and structures through tiny cracks in walls, windows, and doors. They crawl deep into voids, attics, wall voids, and false ceilings. Face flies survive cold winters nestled deep in inaccessible areas of your home or barn.
In the warmth of spring, they emerge and attempt to get outside to mate and lay more eggs. It is in this phase they are considered a pest to humans. Control measures for face flies are very similar to that of cluster flies. Once indoors, you can spray any that you find with a contact insecticide or vacuum them up as they emerge. Strategically placed fly lights may capture them before they buzz around your reading lamp.
The most effective way of controlling face flies to prevent them getting into you home in the first place. Face flies tend to accumulate on the south and west side of buildings because the late summer sun warms these areas the most. Patch and caulk holes and cracks in buildings to prevent face fly entry. However, they can fit through very tiny cracks. Applying a residual microencapsulated insecticide to face fly entry and resting areas will reduce the population. When applying a pesticide, always read and follow the instructions on the label. This is especially important in agricultural applications and areas where cows, horses, or other animals may be present. On a farm, fly control is a never ending endeavor. Highly specific methods of battling face flies directly on and around cattle and livestock are available, but this article is limited to dealing with face flies that overwinter in homes and structures.
Biting Fly Control
Of the many species of flies on earth, a small portion of them require mammalian blood to complete their life cycle. These are known as biting flies. The most common and irritating biting fly is the mosquito. Because of the many diseases spread by the mosquito, the Center for Disease Control considers the mosquito the deadliest animal in the world. Because of this deadly designation and its widespread reach mosquitoes will be discussed in much greater detail in its own article.
Most biting flies have an aquatic link to their life cycle, breeding in ponds and muck near swampy areas, or in very moist leaf litter or rotting logs. Most flies are best controlled when their breeding grounds are disrupted and removed. However, scooping your dog’s poop, or burying an animal carcass is feasible, treating waterways and protected natural environments with pesticides is another matter completely. The food web is intricate and delicate. Fly larvae is often a reliable food source for fish and other aquatic animals. Pest control efforts often requires a balance between human comforts and environmental concerns. This is most clearly evident in controlling biting flies such as mosquitoes and no-see-ums.
No-See-Um or Biting Midge Control
If you have ever spent a beautiful evening in Florida enjoying the intracoastal waterway, you have likely encountered no-see-ums, also called biting midges, sand flies, or punkies. Mosquitoes and house flies get all the credit for ruining outdoor fun, but given the right environment, no-see-ums can set your ankles and feet on fire with their bites. Biting midges are aptly called no-see-ums, as you feel the bite and seemingly swat at nothing. They are so small and quick that you almost never see them in the dawn and dusk when they are most active. Many people refer to this species as sand flies, but that is incorrect, sand flies are actually a different species. No-see-ums are a nuisance, but in the United States they are not associated with the spread of disease in humans.
Biting midges do not breed indoors or parasitize humans or animals, but they sure can cause you to flee a beautiful view or camp site. Like other species of flies, no-see-ums progress through complete metamorphosis; from an egg, larvae, pupae, and then adult. No-see-ums eggs are laid in very wet environments and cannot survive if the area dries out. Breeding areas for biting midges include the salt marsh areas of Florida or very wet soil with large amounts of manure such as cattle or pig farming operations. The amount of eggs a no-see-um lays per batch is dependent upon the species and environmental conditions. One species can lay as many as 450 eggs per batch and other species between 50-100 eggs. Eggs usually hatch between 2-10 days of being laid.
Biting midge larvae emerge from the eggs and require water to develop. They are neither strictly water nor land dwellers. They can usually be found in the muddy banks of a mangrove swamp or salt marsh, in or near a water holding plant such as bromeliads, or at the edge of ponds and lakes. The time period for the larval phase varies greatly depending on the species and conditions; in some situations no-see-ums may remain as larvae for up to 1 year but it usually lasts a few weeks. After a short pupal stage, no-see-ums emerge as adults.
Adult biting midges are usually less than 1/8” in length. Although difficult to see with the naked eye, their wings have hairs which gives the appearance of patterns on their wings. Their mouths have large jaws with teeth equipped for slicing on the females for blood sucking. Male and female no-see-ums feed on nectar, but the females must partake in a blood meal in order for her eggs to mature. Adult no-see-ums live only a few weeks in the natural conditions but can be a major nuisance during that time.
No see ums are rarely treated with pesticides. Fly populations are most effectively controlled when their breeding grounds are eliminated or treated. It is ecologically impossible to treat waterways, marshlands, and mangrove swamps with pesticides. Insecticide treatments targeting adult biting midges are inefficient and offer no long-term control. Most counties that have mosquito programs do not even attempt to control no see ums and will not treat or respond to your complaint.
No see ums are best controlled with mechanical and physical control measures. No see um netting and window screens prevent biting midges from getting indoors. Regular size screens do not prevent no see ums from entering your tent or camper. Outdoor fans may circulate the air enough to keep the biting midges at bay. When outdoors in marshy or swampy areas, wear protective clothing and use a DEET insect repellent. Oil of Lemon Eucalyptus (OLE) is a plant-based, DEET free, EPA registered insect repellent. Repel makes a repellent with this active ingredient that I personally can attest mitigated and repelled no see ums in an environment rich with the pesky biters. Research is being conducted on controlling no see ums by trapping. Similar to mosquitos, no see ums are attracted to humans because of the carbon dioxide that we exhale. Traps attract no-see-ums by releasing CO2 and then sucking the no see ums in with a sucking action similar to a vacuum. Efficacy of these traps is minimal at best, but when combined with other control measures, may help to reduce the sting of no see ums.
Stable Fly
Stable flies are a biting fly that packs a painful punch and prefers to bite cattle and horses. However, if cows and horses are unavailable, the stable fly will easily pierce humans and dogs, goats, sheep, and other farm animals. Stable flies are also referred to as the biting house fly because they look so similar to a house fly, and a dog fly because it so readily attacks man’s best friend.
Similar to many of the flies we have discussed, the stable fly is a filth-breeding fly. The female stable fly lays her eggs in moist decaying organic matter, such as horse and cow manure and decaying or damp hay. The female stable fly may lay up to 800 eggs in her lifetime. Stable flies complete their metamorphosis, from egg to larvae to pupae to adult, in approximately 28 days. Adults are strong fliers and readily move away from their breeding sites to find a blood meal. They are a nuisance to beachgoers on Florida’s panhandle affecting the tourism industry in Florida.
Unlike many other flies, both the male and female stable fly bite. Where only female mosquito and no see ums bite in order to produce and mature eggs, stable flies procure blood meals as their main source of nutrition. Stable flies are aggressive and persistent. In horses and cows, they tend to attack the legs and underside of the belly. In small animals such as dogs, they feed around the superficial blood vessels of the head and ears. When feeding, they can become fully engorged after 5 minutes of feeding. In extreme infestations these bite locations can become infected and leave scarring and disfigurement. Stable fly bites are very painful both to animals and humans and are known to spread diseases.
Stable fly control is similar to that of other filth breeding flies. The first and most important step is to eliminate the breeding source. By promptly and properly removing manure and or wet straw, mulch, and hay the life cycle of the stable fly is disrupted. When not actively feeding, stable flies rest on the underside of vegetation, on fences, and in barns and stables near their hosts. Residual pesticide treatments, fly traps, fly sticky tape, and insect repellent are appropriate control mechanisms for the stable fly. Biological controls using parasitic wasps shows promise in the fight against stable flies. Parasitoid wasps deposits her eggs into the stable fly pupae casing. She kills the stable fly pupae inside thus reducing the stable fly population and increasing the parasitoid wasp population. It is believed that a single parasitoid wasp can kill up to 100 fly pupae in her lifetime. Parasitoid wasps are most effective when used in combination with strict protocols for waste and water management.
Horse Fly, Deer Fly and Yellow Fly Control
Horse, deer, and yellow flies warrant a mention due to their ferocious bites. Although there are few available control measures aside from insect repellent and wearing protective clothing, horse flies and deer flies are bothersome pests to both cattle and horses and humans. Horse flies are large, sometimes up to 1.25 inches in length, where deer flies are smaller but more likely to bite humans. Both horse and deer flies breed in aquatic areas, therefore their life cycle is difficult to disrupt.
Horse and deer flies lay their eggs on sticks, rocks, vegetation, or foliage along muddy swampland, lakes, rivers, and ponds. They almost always lay the eggs on vegetation sticking up out of the water. When the eggs hatch, the larvae fall into the water or very moist soil below and begin to feed. When they are ready to pupate, the larvae move onto drier ground. After a 2-3 week pupal stage, the adult horse or deer fly emerges.
Only the female horse and deer fly bites. They are attracted to mammals by the carbon dioxide exhaled and the warmth from our bodies. The female horse fly and deer fly have sharp cutting blades on their mouthparts that lacerate the skin and cause blood to flow. She then laps up the blood with her spongy mouthpart.
Insecticide treatments to kill horse fly and deer fly larvae is impracticable as the larvae develop in sensitive aquatic environments. Spraying for adult horse flies and deer flies is considered ineffective. Even insect repellents containing DEET have very little effect on horse flies and deer flies. Some very creative trapping devices have been developed and may offer minor relief from biting horse and deer flies.
## Small Fly Control
Tiny flies hovering over the rotting banana on your counter? Have you noticed a small fly or two darting in and out of your kitchen sink? Not your potted plants too! These small flies can not be dealt with by closing the windows or taking out the fly swatter. What are they and what are they doing in your kitchen? Just as the filth-breeding flies of outdoors, these small flies breed indoors in areas where organic matter has accumulated. Decaying fruits and vegetables, food particles in drains and in sink garbage disposals, recycle bins and trash cans, and soil in potted plants are all potential breeding sites for small flies. Residential homes have a plethora of areas where these flies may infest, but the potential for small fly infestation in commercial kitchens is greater still. Areas that may be rarely used and that appear clean may be the source of these pesky and unsanitary flies. Floor drains must be addressed, grease or food trapped in cracks and corners of equipment or storage racks, mop buckets and mop heads can even harbor these small flies. Commercial kitchens should have strong protocols in place for the cleaning of every nook and cranny within its confines.
The most common of the small flies found within homes are the fruit fly, the phorid fly, fungus fly, and the drain fly. Each of these small flies has different characteristics and different control methods, but the consistent theme of fly control remains, you must remove the breeding material. Accumulation of even a small amount of organic debris, can cause a small fly infestation.
Fruit Fly Control
Fruit flies are among the smallest fly pests found in the home at about 1/8” in length. Most, but not all fruit flies, have bright red compound eyes and are most frequently seen flying around and inside the fruit basket. Fruit flies seem to be most prevalent in late summer and early fall. Fruit flies are often noticed in garbage cans when trash “juice” leaks into the bottom of the can. Fruit flies can smell the odor of rotting fruit and make their way into your home via the smallest of holes. They reproduce quickly if the source is not located, removed, and cleaned. Even if the rotten banana is discarded, fruit flies may remain if the rotten juice is not wiped from the counter.
Fruit fly infestations may be difficult to track down. Check the pantry for an old bag of potatoes, check the drip pan under the refrigerator, an apple juice spill that may have trailed under the stove could be the breeding spot. Soda lines of drink dispensing machines are notorious for breeding fruit flies. All stages of fruit fly metamorphosis depend upon rotting fruit and vegetable matter, but the larvae can only survive in rotting fruit and vegetable matter with moisture.
Vinegar and light traps can kill adult fruit flies, but they will not prevent the immature fruit flies from developing into adults. Cleaning and removing the organic matter breeding source is the only way to eliminate the fruit fly infestation. This can be as simple as wiping down the counter or the pantry. However, if the source is inside the drain, this becomes more difficult. Inside your drain lines and in sink disposal is thick caked on grime, which is the perfect place for fruit fly eggs and larvae to develop. Enzyme based products that “eat” the organic grime are highly effective. These products are a thick viscous gel that clings to the sides of the drains and eventually cleans the gunk that is allowing the flies to reproduce. These products can be used in the drain every day for the first week or two. Once the drain is clean and is no longer breeding flies, maintain the cleanliness by using the enzyme based product twice a month. These enzyme based cleaners are not pesticides, have a very pleasant citrus odor, and may be added to mop water to clean organic grime from floors and other fruit fly breeding sites.
In kitchens where fruit flies are a common problem, insect growth regulators work to break the life cycle. Insect growth regulators do not kill adult fruit flies, rather they prevent immature flies from becoming adults. Insect growth regulators are available in convenient aerosol formulations and liquid concentrates. It is vitally important that you only apply these products as permitted by the label.
Commercially available fruit fly traps are effective for capturing adults and reducing aggravation while you seek and destroy the source. These pre-filled plastic reservoirs contain a fruit fly attractant. They contain no pesticides and are non-toxic. Once the fruit fly comes to explore, he is trapped in solution and dies. Fruit fly traps are easily home made as well. Place vinegar and a small amount of soap in a dish and cover with plastic wrap. Poke holes in the plastic wrap. The fruit flies will come to the dish and attempt to land on the vinegar. However, the soap disrupts the surface tension and the fruit fly will drown. Again, focus on sanitation, do not expect to trap a fruit fly infestation out of your home.
Drain Fly/Moth Fly
Drain flies are also commonly referred to as moth flies, sewer flies, or filter flies. They have a markedly different appearance than other small flies that may infest your home. Drain flies are about 1/8” in length, are usually grey or black in color but they may be brown to tan. Their bodies and wings are covered with hairs that give them a moth like fuzzy mottled appearance. When at rest, the drain fly places his wings over his body like a roof. Adult drain flies are often seen at rest during the day on bathroom or kitchen walls near the breeding site. The presence of drain may indicate a slow or clogged drain, but moth flies may breed in other areas such as water traps of plumbing fixtures, sewage lines, and any other place where wet organic matter accumulates.
Drain flies lay their eggs in the slimy organic gunk that accumulates in a slow or clogged drain or in wet rich soil. They are also commonly found in showers behind cracked or missing tiles where organic matter accumulates. When the eggs hatch, the larvae feed on the accumulation of organic matter film into which he emerged. Adult drain flies are poor fliers and are often located near the breeding site.
To control drain flies, you must clean the environment in which they are breeding. If you are unsure if a particular drain is the breeding location, cover the drain with clear tape for 24 hours. Remove the tape and inspect it for drain flies. If there are flies on the tape, you have found your breeding source. The drain can be cleaned with a wire pipe brush scraping down the sides to remove the organic matter. Pouring boiling water or bleach down the drain will not solve the drain fly problem.
Enzyme drain cleaning products have proven highly effective at removing this fly breeding grime from drains and other hard to reach areas. The enzymes eat away at the organic matter and remove the ability for drain flies to reproduce. In commercial kitchens these products should be used to maintain clean drains and prevent an infestation of drain flies. These products are formulated in many variations ensuring a thorough sanitation job. From a thick viscous gel which clings to the sides of the drain, aerosol foams packaged with long extension hoses, to liquid concentrates to add to mop water, and foaming concentrates, you can apply these products to the breeding sites, no matter how deep they hide. Apply the drain cleaning product to the drain nightly for at least five consecutive nights. Until all of the breeding material is removed from the sink, the drain, the garbage disposal, and the pipes, drain flies will persist.
The time span for drain fly control depends upon the amount of buildup present and the severity of the infestation. Once drain flies are under control, we recommend preventing a reinfestation by keeping the drain clean and free of organic debris. Enzymatic drain cleaners can be applied weekly to maintain clean drains prevent drain flies.
Phorid Fly
Phorid flies, also known as Scuttle flies, Jitter flies, Humpback flies, and Sewer flies, will most often be found in moist decaying organic material found in drains, garbage cans and dumpsters, and compost piles. Phorid flies are small, approximately 0.5 mm in length, and usually black or dark brown in color.
Phorid flies are often confused with fruit flies, but phorid flies do not have the characteristic red eyes of the fruit fly. Phorid flies have a distinctive hump behind their heads, thus the nickname Humpback fly. Although they have wings and can fly, albeit erratically and for short periods of time, phorid flies are often seen running along a surface to escape rather than taking flight. This tendency has earned them the nickname Scuttle fly. By whatever name you choose to call them, phorid flies are a pesky invader in homes and businesses.
Phorid flies have a tremendous potential for reproduction. The female phorid fly can lay up to 40 eggs in a 12 hour period, which amounts to approximately 500 eggs during her lifetime. These eggs are deposited in or near rotting organic matter. Like other flies, phorid flies undergo complete metamorphosis, changing from egg, to larvae, to pupae, to adult. Depending upon the temperature and nutrition available, the phorid fly’s life cycle takes between 14-37 days.
To treat and eliminate phorid flies from your home or business, you must locate the breeding source. A minor phorid fly infestation may be solved by throwing away the tomato that is rotting on your counter. However, it is often much more complicated than that. While fruit flies limit their breeding sources to rotting fruits and vegetables, phorid flies are often found in litter boxes, garbage on meat leftovers, and mausoleums. Similar to fruit flies and drain flies, if your phorid fly invasion is coming from the sink or drain, it is likely treatable by cleaning the drain. By thoroughly removing decaying organic matter from the sink and floor drains using enzyme biological cleaners, the phorid fly breeding habitat will be eliminated, thus eliminating your phorid fly infestation. In commercial kitchens, special and regular attention should be paid to floor drains and heavy and specialized equipment. Tiny amounts of food debris are often dropped onto the floor and become wedged between the floor and the feet of prep tables and heavy equipment. When food bits from a bakery or restaurant is stuck in the cracks and crevices of the tools of the trade, a nutrient rich phorid fly environment is created. Cleaning schedules and protocols should be developed and followed to ensure phorid flies have no suitable place to lay eggs.
Phorid flies breed wherever excess moisture and organic materials combine. In addition to sinks and floor drains, phorid flies can breed in immense numbers if a pipe breaks open underneath the concrete slab of a structure. To narrow down the breeding location, place pieces of tape over any cracks or floor drains. Should you be unlucky enough to have a broken pipe under the concrete slab filled with organic matter and acting as a breeding reservoir, you don’t have many options. You can not drill into the floor and inject insecticide hoping this will solve the phorid fly assault. It will not work and there is no insecticide labeled for such a treatment. Your only option is both costly and invasive. You must access the broken pipe, repair and thoroughly clean it, and put your home or business back together. This often requires the assistance of licensed and insured tradesmen such as a contractor and plumber. As inconvenient and expensive as this process is, it remains true that to control flies, you must remove their breeding grounds.
As you work to eliminate the breeding grounds for phorid flies, you will find some relief by using alternative means of fly control. Contact aerosols (spray) will kill any adults that you find but will never eliminate the problem. Installing fly lights to attract and kill the flies will reduce the irritating adult population some. However, do not exchange spray or insect lights for doing the hard work of eliminating the phorid fly breeding source. Until you eliminate the breeding source, whether it be in the trash can, the drains, the basement, or a broken sewer pipe, phorid flies will persist.
Fungus Gnats
Fungus gnats are a small fly that resembles a mosquito. Fungus gnat adults are approximately 1/8” in length with long legs and antennae. They have a distinct Y pattern on their wings. They do not bite, but are irritating when present in large numbers. Indoors, fungus gnats breed in the moist soil of potted plants.
Fungus gnats preferred breeding environment is the first 2-3 inches of moist soil. Adult fungus gnats lay eggs in the cracks and crevices of growing medium. Soils that are rich in peat moss is most attractive to fungus gnats. From the eggs, fungus gnat larvae emerge. The larvae are about ¼” long when fully grown and they feed on algae, fungus, and decaying plant matter found in the soil. Fungus gnat larve will also feed on root hairs and tender young roots. After 2-3 weeks, the larvae pupate in silk-like cocoons in the soil.
A female fungus gnat can lay up to 200 eggs in her lifetime. Because indoor (and greenhouse) temperatures are fairly consistent, the indoor life cycle is reliably 3-4 weeks from egg to adult. Indoors, fungus gnats can reproduce year-round. You may notice a fungus gnat spike in winter if you bring plants inside to escape the cold winter months. While indoor potted plants make our homes and lives healthier, happier, and more beautiful, they may also infest your home with fungus gnats.
Adult fungus gnats are most often seen close by the plant in whose soil they are breeding. They are strongly attracted to light and will often be seen at windows as well. As the name suggests, fungus gnats primarily eat fungus found in soil. The moisture level of the soil is the most important factor in getting rid of fungus gnats. Without moist soil, fungus gnat larvae can not survive and become adults. The most effective solution is to adjust the watering schedule and avoid overwatering your house plants. If fungus gnats are present, allow the first 1-2 inches of soil to dry out before watering the house plant again. The drier environment will decrease the survival of eggs and larvae and will make that potted plant a less attractive location for adults to lay their eggs. For most residential fungus gnat situations, the solutions really is that simple.
Occasionally, despite a reduction of the moisture level, fungus gnats continue to plague you. Consider re-potting your indoor plants. Once potting soil has “broken down” it may retain excess moisture. This is neither beneficial to your plant, but also encourages fungus gnats. If you have any pots with decaying bulbs and roots in your home, remove them. Insecticide treatments may be necessary to kill larvae and adult fungus gnats. A systemic insecticide such as imidacloprid, has been shown to kill fungus gnat larvae. A pyrethroid based insecticide labeled for fungus gnats and applied according to the instructions on the label, can be effective at killing adult fungus flies. To quickly reduce the adult fungus gnat population without insecticides, place yellow sticky cards near the affected plant. The fungus gnats will be attracted to the yellow color and become stuck on the glue card.
With proper plant watering practices and perhaps an insecticide treatment, fungus gnats are easily controlled and should never hinder you from bringing plants into your home. As with all flies, find the fungus fly breeding source and make adjustments so that fungus flies are not attracted to that plant and can not survive in the potting soil.
