Pegasus Pest Control can advise on and supply a wide range of electric fly killing units (also known as ‘fly zappers’).  The size and style will depend upon several factors.  These include whether they are in food environments, wet environments, seating areas, heavily infested areas etc.  They are supplied with an ongoing maintenance programme to ensure the machine is working to optimum performance.  This includes an annual tube change in the spring to coincide with summer fly populations.  Demonstration of due diligence is an important benefit of having an ongoing service contract in the food industry.

Quality units provide many advantages over cheaper brands.  These include over all energy saving, increased attraction to flies, and good longevity.  Poor quality units, for example, will not withstand emptying and servicing beyond a couple of times.   Using lower wattage tubes does not necessarily equate to less energy consumption.  Less energy consumption is dependent on the quality of ballast used by the manufacturer, the phosphor mix inside the tube, as well as a number of other components.  A less quality ballast will result in more energy being consumed in heat output.


How Do Fly Killers Work?

Fly killing units work by attracting flying insects to either a high voltage grid or a sticky board.  The blue (sometimes green) light tubes emit light, including ultra violet light.  This ultra violet light is out of the range of light visible to humans.  Light between 380nm and 780nm is visible to the naked eye.  This encompasses the seven colours of the rainbow.  Ultraviolet light is in the spectrum between 100 and 400 nanometres and is generally subdivided into three categories:

  •    UVC – 100-280 nm
  •    UVB – 280-315 nm
  •    UVA – 315-400 nm

UVC is frequently used for its germicidal properties in sterilizing units, water treatment plants, etc.  UVB is the sun tanning light emitted from the sun.  The UVA wavelengths are considered harmless to humans and are used in electric fly units.  Research was shown that light in the 350-370 nm wavelength is optimum for attracting insects.


What Do Flies See?

Light is captured in the eyes of insects by structures called ommatidia.  An adult house fly has around 3000 ommatidia in each eye.  These can be seen as hexagonal patterns under a microscope.  Each ommatidia has eight sensory cells, each of which contains a photopigment which responds to light of a particular wavelength.  This photopigment is unique to flies.  These specializations are linked to the complex behaviour of flies.  The highly attuned sensitivity to ultraviolet light is thought to be a navigational aid when using light from the sun or moon.

Research into the physiological features of fly’s eyes only reveals what the fly can detect rather than what they see.  Only with detailed and complex experiments can we get clues what the fly sees.  Each fly species has different visual sensitivities that vary according to the age of the fly, its gender, feeding status, reproductive stage etc.  This makes the use of fly killing units only an aid in fly control, within an integrated programme, rather than a single cure.


Where Should Fly Killing Units Be Located?

As discussed, fly killers rely on the fly’s sensitivity to ultraviolet light.  Therefore, both natural daylight and artificial light can be in competition to the light emitted from the unit.  For this reason, a unit should ideally be located away from sources of light such as a window.

Also, as they attract flies, they should not be placed facing an outside window where possible.  This is because flies can detect a unit inside the building from outside and then be attracted in.  A common place to site a fly killing unit is on the wall above an external window.  This is so that once a fly has entered a building it is more likely to be intercepted into the unit before it progresses any further into sensitive areas.  Fly killers are also a useful monitoring tool for highlighting problem areas.


Servicing of Fly Killing Units

Another consideration regarding where fly killers should be located is servicing.  Units should be regularly serviced to keep them functioning at optimum performance.  A good height is around 2.5 meters.  This height is good for access  and has also been shown to be optimal height to intercept flight paths.

The light tubes should be changed at least annually.  This is because the ultraviolet light emitted reduces over time due to a slow degradation of the fluorescent powder coatings on the inside of the glass tubes.  Higher quality tubes have a slower degradation rate than cheaper brands due to the quality of materials used.  In sensitive areas the tubes should be changed every six months.

It is often not practical to meet all the above recommended criteria for unit location.  However, keeping these principles in mind will help with good decision making.  Feel free to call Orlando Jackson at Pegasus Pest Control on 07519 118856 for a discussion.


Types of Units

Units which have a high voltage grid have a greater capacity to control flies than sticky board varieties.  The catch tray can be removed to allow greater catch capacity in situations of heavy infestation.  This is particularly useful in monitoring cluster fly infestations.

However, with grid varieties there is a greater chance of fly parts being ejected from the machine and potentially contaminating high risk areas below. Therefore, killing grid units should not be located above sensitive areas such as food preparation surfaces.  Sticky boards will need replacing at least quarterly, depending on catch levels.


Glass Safety

Considering food safety, UV tubes used in food environments should be coated with a plastic sleeve to render it shatter proof.  Any broken glass from the tube will be retained within the sleeve.  The quality of sleeve can vary too.  A quality sleeve will not melt, degrade, break, fade or discolour.  Sleeve coatings should ideally comply with international standard EN 61549.

Here are some of the quality units recommended by Pegasus Pest Control (all images courtesy of PestWest):

Chameleon 1×2.  A wall mounted sticky board variety for sensitive food environments.  90m³ coverage.  Weight 4.3kg.




Chameleon 2×2.  Ceiling mounted double sided sticky board variety.  180m³ coverage.  Ideal for larger industrial sensitive areas.  Weight 6kg.



Titan Alpha.  Grid variety.  80m³ coverage.  Multiple mounting options, easy to service, ideal for shops and smaller commercial situations.  Weight 4kg.



Titan 300 Stainless Steel. Grid variety.  90m³ coverage.  Multiple mounting options. Easy to service.  Removable spring-loaded grid for thorough cleaning. Ideal for larger kitchens and all commercial uses.  Can cope with heavy fly infestations by removing the tray.  Weight 7.5kg.



Chameleon Uplight.  Sticky board variety.  40m³ coverage. Discrete, disguised as a wall scnonce.  Front cover can be painted or decorated to match decor.  Weight 3.7kg.


A wider variety of quality units can be supplied according to requirements.

Call Pegasus Pest Control on 01458 252 551 or 07519 118856 to book a free survey and quote.