Insect control articles and pest control news

11 May 2018

Waste, flies and opportunities for pest controllers

Pest control | PPC91 May 2018

As the process of how we deal with our waste evolves, so does our requirement to protect it from flies. Clive Boase, Principal Consultant of BPCA member company the Pest Management Consultancy, explores the problem and investigates whether there’s money to be made for pest management companies willing to roll their sleeves up (figuratively of course).

 Wheres theres muck waste flies and oppertunities

Speed read

The waste management industry has seen massive changes in the last couple of decades. These changes have reduced waste, increased recycling, and have generally been good for the environment. However, at some sites, there has been some not-so-good news: namely increased fly problems. This article looks at the changes in the waste industry, the fly problems that have arisen, and the role of pest control organisations in dealing with those problems.

Drivers for change

In the early 1990s, there were widespread concerns about the lack of new landfill sites, the release of environmentally-damaging gases from landfill sites, and the loss of useful recyclable materials. 

To address these concerns, the Landfill Tax was introduced in 1996. By placing a tax on waste going to landfill, it was hoped that other more sustainable ways of dealing with waste would then become viable.

Each branch of the waste industry has its particular fly

An industry in flux

Before the introduction of the Landfill Tax, the waste industry had a relatively simple structure. Most mixed household waste was collected weekly and was then tipped at a landfill site. 

However, since 1996, that has changed completely. Most waste is now collected fortnightly and is typically separated into different streams, each with its own type of processing. Green waste and food waste is often composted or digested, producing methane for energy and compost for soil improvement. Mixed waste now has the plastics, ferrous and non-ferrous metals extracted from it, which are then baled and stockpiled ready for recycling. The remaining residual waste is typically composted to reduce the moisture content and is then baled, stockpiled, and exported for use as fuel in power stations.

Overall the Landfill Tax had the desired effect, stimulating a wave of innovation across the UK waste industry, with the five largest companies now having an annual revenue totalling close to £5billion.

 Pupae at base of stack

Dispersion, complaints and enforcement

Since the dawn of civilisation we have known that accumulations of waste attract flies. Depending on the type of waste there may be houseflies, blowflies, scuttle flies, fruit flies or others. Large infestations of these flies can develop on waste sites if they are not effectively managed, and may result in the site failing to comply with the standards set by regulators. In addition the common housefly will disperse away from sources such as waste sites, fly distances of a kilometre or more, and then enter buildings to cause a nuisance to people there. This can result in negative publicity for the site, and possibly in more enforcement action. For many waste sites, fly complaints and the resulting regulatory pressures are constant worries during the warmer months.

Each branch of the waste industry has its particular fly problems, often specific to the processes used on that site, and each requiring specific solutions. For example, there are still some active landfill sites, with flies emerging from poorly-covered waste and generating fly complaints in nearby residential areas. Green waste composting sites are generally less likely to develop major housefly problems unless food waste is added to help the composting process. At sites where this does occur the risk of development of major fly populations is greatly increased, aided by the warmth generated during the composting process.

When all the useful materials have been extracted from mixed waste the residual waste is often baled and wrapped for use as fuel.

Even this baled waste is at risk of infestation especially if the wrapping is damaged and allows ingress of water and oxygen. Fly problems with baled waste have sometimes been severe, particularly where hundreds or thousands of bales have been stacked in dockside areas awaiting export.

Recyclable materials such as plastics or metals can also be vulnerable to infestation. Various species of flies including houseflies, fruit flies and scuttle flies seek out and develop within the slimy deposits of food and drink in stockpiled bales of containers awaiting recycling.

Reception tipping

Monitoring, prevention and control

Regulators require waste sites to develop a fly management plan, which assesses the risks of fly infestation on their site and sets out how they will prevent problems using fly monitoring, preventative measures, and insecticide use.

At the core of an effective plan to prevent and control flies, will be a monitoring programme often using adhesive fly cards. The objective will be to identify those hotspots on the site where flies are actually developing and show their trends.

Once the main areas of fly development and activity are located then effective, non-chemical, preventative measures should be put in place. These may take some careful thought to develop and will require working closely with the site. However, these can achieve sustainable and long-lasting fly suppression without the risk of resistance. Even relatively simple measures, such as ensuring all waste in transfer stations is moved out within 48 hours of arrival, and that tipping bays are regularly cleaned, can make a big improvement to fly numbers. There will be many other preventative measures that are appropriate to specific branches of the waste management industry.

Red top traps

In addition to preventative and sustainable measures, a battery of different insecticide treatments is also used across the industry. Space-spraying with non-residual pyrethroids is widely-used with some sites having a permanently plumbed-in system (a tank, pump and control unit at floor level) connected to one or more atomiser heads situated in the roof of the building. Others rely on more conventional hand-held ULV units.

Residual spraying of the waste itself, or of surfaces on which flies rest, is still common and often with a backpack mist-blower. Insecticide fly baits are often used, applied to boards or sometimes to structural surfaces within buildings. At some types of site, particularly mechanical and biological treatment sites, fly larvicides are routinely applied to the waste during processing to prevent fly development.

One of the issues arising from this intensive insecticide use is the risk of development of insecticide resistance. In other sectors, such as animal husbandry, experience has shown that if insecticides are frequently used then houseflies quickly develop resistance. Houseflies at waste sites have not yet been studied so closely but the risks are undoubtedly there. Effective and sustainable fly management will therefore require a focus on the use of non-chemical measures, as well as careful use of insecticides when required.

Opportunities, for some

There are several private pest control organisations which have already recognised the opportunities in this sector and are now working hard on fly control. Some are recommending and providing non-chemical fly control, some apply insecticides when required, while others do both.

However, at most waste sites fly management is currently carried out by the waste company itself. They buy their insecticide and spray equipment direct from a distributor and train their staff to use it. With this approach there may be some short-term cost savings, staff are on-hand if required, they know the site well but there may also be downsides. Inhouse staff tend not to acquire the same breadth of experience and understanding as servicing company technicians, who visit many different sites weekly, talk with pest control colleagues, read the pest control magazines and attend pest control events. There is therefore a strong case for professional pest control companies with their wider experience to become more involved with flies and waste sites.

Having said that, this work may not suit every pest control company. The standard eight or 12 visits per year are not going to be appropriate. New business models may need to be developed. Successful pest control organisations will need to develop an understanding of the operation of the waste management industry, work on their ability to monitor, prevent and control flies, develop a convincing sales pitch and, importantly, figure out a way to make it pay. Nonetheless, where there are major opportunities then experience shows that there will be organisations who will take up this challenge. With the fly season just around the corner now there is no time to waste!


Clive teaches a BPCA training programme called Pest Management of Waste Sites which is perfect for companies looking to branch out into the waste sector. For more information contact...

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Clive BoaseClive Boase
Principal Consultant of the Pest Management Consultancy

1 May 2018  |  PPC91

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