Flies Control Measures
Flies are an often sight in rural and urban parts of Australia and can be a serious pest in commercial buildings which have a somewhat lower sanitation standard. It does not matter if you are in a coffee shop or in a restaurant, you are very likely to meet one or more fly species. Flies are not only a pest but also a disease carrier and some of these diseases can be fatal for humans.
All flies belong to the Diptera order which is one of the largest orders in the world with 150,00 species in it. From those, 6,000 species can be found in Australia. Only 25% of species in the Diptera order are described and properly named. They inhabit all parts of Australia but most of them can be found in forests and near fresh water sources.
Despite some differences in their structure, the majority of adult flies can be recognised easily by having only one pair of wings that are functional. The hind wings are known as “halteres” and they vibrate during flight. They are actually a gyroscopic organ that gives them balance during flying. Head carries a pair of large eyes and an antenna. Their mouthparts are made for sucking and mopping up nectar. Some species such as mosquitoes have mouthparts that have evolved into biting tools that can pierce skin and suck blood.
During their lifecycle, flies go through a complete metamorphosis. Most adult females are oviparous and lay eggs near or on food sources. Some flies such as those that belong to the family Sarcophagidae are known as flesh flies. They are viviparous which means that they deposit live larvae on decomposing matter. The emerging larvae feed on decomposing vegetable matter and some are even predatory or parasitic. Mosquitoes for instance are aquatic and feed upon food in the water. After they are fully fed, the pupate and after a short period of time, adults emerge.
Flies are a very common sight in Australia and although a couple of them can be a benefit to nature, they are always a nuisance to humans. They carry diseases such as typhoid, cholera, diarrhoea, dysentery and worms.
Not all flies are problematic but there are some that are known to cause trouble. Not all species can be treated by pest controllers as some species such as vinegar flies are very difficult to control.
These are the species that we come in contact with:
- Muscidae family – this is a very big family with many different species that have economic and medical importance. Best known species is the Musca domestica, a house fly which can grow from 5 to 8 mm and have a grey thorax abdomen. Adults are known to carry a broad range of pathogenic bacteria that can affect both humans and domestic animals. House flies are very common in domestic areas and for some reason they like our dinner plates. Larvae can be found present in animal faeces and decomposing matter. A lesser house fly (Fannia canicularis) is also a very common and known species which can be distinguished by its erratic flight. Adults are from 3 to 6 mm long with grey thorax and abdomen. They have distinctive stripes on the thorax. Adults are found in domestic areas and animal houses. Larvae feed on organic matter. Rather uncommon species is the stable fly (Stomoxys calcitrans) and it is very rare in houses but common in animal facilities. These flies are about 5 to 7 mm in size and have a very distinctive piercing and sucking mouthparts. They rest with their wings widely apart. The larvae feed on almost all organic material while adults feed on animal blood.
- Bluebottles or blow flies (Family Calliphoridae) – also a very large family with a stouter build than those from Muscidae. They grow up to 13 mm in size and can come in a variety of colours which range from black, green, blue and bronze. Adults are strongly attracted to moisture and eat mainly nectar, honey and other sweet liquids. Although they can be seen in massive numbers, they are very rare as pests or disease carriers. The larvae are known to cause “blow fly strike” in sheep which is a condition that causes many millions of dollars in damage to the industry.
- Mosquitoes (family Culicidae) – Adults have a long proboscis which males use to eat nectar. Female mosquitoes feed on blood and as such are known as disease carriers. When we talk about Australia, mosquito related diseases are isolated to the northern tropical regions. However, various species can be carrying some serious diseases such as malaria, dengue fever and the Ross River virus in humans and encephalitis in horses. Mosquitoes can carry malaria which is one of the most infectious diseases which kills around 3 million people every year. Australia is home to over 300 species of mosquitoes. All of them start their life as aquatic larvae from which adults emerge in 7 days when optimum conditions are present. Mosquitoes can breed in many natural and artificial sources of fresh and salt water.
- Fruit flies (family Tephritidae) can be found everywhere there is fruit and vinegar fly can be found primarily around decaying fruit. Fruit flies (Dacus spp.) are a very important pest to commercial industries and can cause significant damage if left untreated. Adults eat sap, nectar, honey and droppings. Vinegar flies can become a problem in homes and restaurants when there is a presence of rotting or decaying fruit. Adults can grow from 3 to 6 mm and have brown and yellow or brown and black eyes while some can even have completely red eyes. Their head and thorax is tan while the abdomen is black. When indoors, these flies can be seen flying over fruit and veggies, garbage and bottles of fruit juices, beer, wine and vinegar. They are famous for their quick breeding abilities and you can sometimes see hundreds of them in one food source. They are very difficult to control because many clients can be hard to convince that the sole reason behind the issue is the poor hygiene.
- Drain or Moth flies (family Psychodidae) can be often seen in bathrooms and toilets. Adult flies can become very common indoors around drains and urinals. They are the result of drain issues such as blocked and broken drains. When you have blocked drains, organic matter accumulates on which drain flies feed. Same as Vinegar flies, Drain flies are a result of low hygiene. Adult Moth flies are very small, typically between 4 and 5mm with dark colour body which is covered in hair. They have hair on their wings and very long antennae. Wings can seem as too large for their body and are somewhat similar to the roof when they are resting. They are very poor fliers and their flight is very irregular.
- Flesh flies (family Sarcophagidae) can grow up to 13 mm and have a striped thorax and a pattern on their abdomen. They can be found near carcasses such as dead rats. If you see them on the wall or a ceiling, you can be certain that there is something dead in the vicinity.
- Sciarid (family Sciaridae) is a very common family of small flies. Their larvae can be found in great numbers on rotting vegetables or soils with high amounts of organic matter. Pest controllers can find them in houses with pot plants in which they are breeding. Adults are a big annoyance to house owners as they can start to believe that they are being bitten.
- Phorid (Hunchback) flies from the family Phoridae have very similar habits as Sciarid flies. Adult Phorid flies are very small with a very large thorax. They can be found in houses with gardens and pot plants. They also can give the illusion that they are biting people.
Successful control of flies is a procedure that requires great knowledge, resources and cooperation from the client. It is not a simple drive to the location and spraying all over. It requires a careful inspection of the premises before starting with any action. It is not important how many flies you manage to kill, it is important to not let any to live. You will need to carry out a risk assessment before starting any work and while at it, you can check at the following as well:
- Geographic area – premises in rural parts can be located in the vicinity of more than one reservoir of arthropods. If the premise is located near a water source, you will have to deal with mosquitoes, water beetles and midges.
- Premise orientation – free standing premises, wind orientation and entry door location all have influence on the number of pests that can enter.
- Structure details – Age, way of construction, current status, design and all other structure details will have influence on the building's susceptibility to pests.
- Premise culture – Your success will depend strongly on your cooperation with the owners. If the owners leave their windows open and leave organic garbage in the premise, it will have a negative effect on your treatment and its results.
Three Control Parameters
Surely, if you can prevent flying pests to enter the site, you are almost done. Some of exclusion measures:
- Flyscreens – there can be mounted on all doors and windows as an effective pest exclusion device.
- Airlocks – when they are properly designed and maintained regularly, they can be an effective method of prevention for all flying insects.
- Air curtains - these are very rarely used because of the associated costs and a somewhat varying level of efficiency. If they are not used correctly, they will not provide much protection as flies can simply walk on the ground and enter the site.
- Strip curtains – these are often made of plastic and have a broad range of design and thickness. Smaller ones are usually used in houses. They usually leave a gap on the floor which allows insects to enter. Sometimes, their level of protection is almost none as they are tied to the door handles.
When talking about restriction, we basically mean to reduce the breeding capabilities by removing their food sources and breeding locations. Some elements of a successful restriction are:
- Waste removal – everywhere where there is waste, there are pests. All dumpsters and trash bins should be located on a raised platform which will allow effective drainage and easy washing. All containers should be closed and waste bins should be located away from the building. They should be emptied according to a strict schedule and should not be allowed to overflow.
- Removal of breeding locations – this is especially important in mosquito control and includes the disposal of old tyres, buckets, tins and other containers that could keep standing water. This step is also important in controlling vinegar flies as their larvae could be feeding in these locations. Without controlling these as well as other locations such as bar and floor mats, pest control can be almost impossible to achieve.
- External lights – this is in most cases completely overlooked by everyone, including the pest controllers. It is important for most premises to have external lightning for security. Fluorescent tubes and mercury vapour lamps are very attractive to most flying insects. There are special coloured bulbs that have a very small attractiveness level to insects but all lamps should be placed at leasts 5 metres from entry points.
This is the most important part for every pest controller. There is an infinite number of chemical and non-chemical products that can be used as a control measure. We can say without hesitation that every insecticide on the market will kill flies but this does not mean that you should pick the first one and go on a killing spree. There is a number of things that you should check and the first one is to make sure that your product is effective against the pest you are fighting. Make sure to read the label on the product before using it. Some insecticides that you can use are:
- Fly bait – these are usually in a granular formulation and are very effective mostly because they can be applied as a dry granule and scattered around, placed in bait stations or mixed into a paste and applied to vertical surfaces.
- Residual insecticidal application – usage of Synthetic Pyrethroids around doors, windows and trash cans will repel and destroy flies. Adding sugar will attract flies to the surfaces that have been treated. Some of them are mixed with water and painted on surfaces. Some products contain not only sugar but their sex attractant as well.
- Insect growth regulators – these are used to control mosquitoes in aquatic areas. They come in a range of formulations and are very effective.
- Drain cleaners – these are special products that are used to clean drains and pipes of all organic matter. This way, they remove potential food sources for vinegar flies.
- Metered aerosol dispensers – these are effective against flying insects in limited spaces such as store rooms and garbage rooms. These dispensers use a pyrethrin insecticidal spray and can be used in aerosol cans with aromatic fragrances.
- Space treatments – metered aerosol dispensers are used for small spaces but when you need to treat a large space, you should use an electric or petrol powered fogging device. These devices use pyrethrin as the active ingredient and are very effective against flying pests.
- Electronic fly killers – you can see these in your local take-away food place. Even worse, these devices can be seen hanging above a food counter. They should be used in the appropriate way so they can be effective.
These devices all come with a price and they should be used in the best way possible. Here are some points that should be considered before installation:
- During the site survey, check all entry points and hot spots where flies can be seen in large numbers. Is there a chance of contamination for products? Are the doors left open all the time? Are there any trash bins next to doors or windows? These are all locations where these units could be placed.
- Electronic fly killers are not like vacuum cleaners and there are many factors that should be considered. For example, flies will not be affected to UV tubes at distances of 30 metres. They will respond to them when the distance is less than 4 metres.
- Flies level of responsiveness to these devices varies over time. They can go from full attraction to complete disinterest over time but research shows that 90% of flies will be caught in the first 24 hours.
- Height of units is also critical in their effectiveness. They are known to produce best results when placed 1 metre above ground.
- Devices should be placed in the vicinity of all entrance points and at right angles to the nearest window or light source. They should not be visible from the outside as they could attract even more flies.
- Suspended units should be 2 metres away from light walls because UV light that is reflected from these walls has a reduced effectiveness.
- Do not place electronic devices over areas where products are prepared. They should be 10 metres away from foodstuff and 5 metres from packaging.
- UV tubes need to be changed according the specifications by their manufacturers. Their efficiency drops after their scheduled life which is typically between 6 months and 1 year.
Flies can be very troublesome pests as they can annoy most of us but more importantly, they are known to spread a wide range of serious diseases, some of which can be deadly. They breed quickly and can breed almost anywhere which makes it very difficult for pest controllers to put a stop to them. When starting a fly control job, make sure that you have checked the following:
- Identify the target species
- Carry out a detailed site assessment
- Evaluate all possible control measures
- Use the most appropriate insecticide products
- Read the labels!
Flies can move very quickly and can be killed very quickly. However, they can bounce back to full population in a matter of days because of their quick breeding.
If you still struggle with flies or if you want a complete pest solution that involves not only protecting your family from flies hiding in areas you haven't noticed, but also other pests such as rats, termites, cockroaches and bed bugs, contact professional services.