Flies. The bane of many a manufacturer/restaurateur/ hotelier's existence, and as such a frequent topic on here on deBugged. We've looked at why integrated fly control is so important, as well as topics like fly control advice for Hoteliers and the rise of the Mango fly, to name but a few.
But this being February - and therefore the month of love - we thought we'd take a look at the science behind why flies are attracted to an insect light trap (ILT) and why flies love LED's more than traditional fluorescents.
Why LEDs make a better insect light trap
Attractiveness to flies
Because wavelengths of light outside the visible light range are far more attractive to flies than those that fall within it, an effective ILT should have LED lamps which are manufactured to emit those particular wavelengths to which flies are best attuned.
The graph above shows the sensitivity of the photoreceptors in a house fly’s eyes to different wavelengths of light. This shows that the fly’s photoreceptors are tuned to wavelengths around 350 nanometres, which is close to the UV output of the Lumnia LEDs (365 nm).
LED lamps produce intense light in the most sensitive part of the UV spectrum that flies can see. There is little UV light in indoor environments, therefore, the LED lamps will appear to the flies as bright sources of light and attract them to the unit.
Fluorescent lamps, on the other hand, are manufactured in different ways with different compounds to alter the wavelengths emitted, and to different standards of manufacture. They also fade quickly, reducing their effectiveness.
The greater brightness of the LED lamps also means that Lumnia ILTs have a greater reach: the distance at which the light is bright enough to attract insects. In testing our Lumnia ILTs, the reach of the LED lamp strip was determined to be 80% greater (UV light measured in watts per square metre on a flat surface) than a traditional L3 fluorescent tube.
An LED lamp will attract flies and other insects at greater distances, which also means that in a large space, fewer units are required as they can be placed further apart. This saves costs for businesses threefold – in the number of ILTs, electricity costs and lamp replacement.
As everyone who has LED bulbs in their home knows, LED bulbs have a significant energy saving over conventional light bulbs. This is also true for the conventional fluorescent bulbs used in ILTs. A typical LED strip used in an ILT uses only 10 watts of power, compared to 60–90 watts for units with fluorescent tubes.
In our own tests, we’ve found that a Lumnia ILT with Lumnia LED lamps can save up to 70% of power compared to equivalent traps with fluorescent tubes and the carbon footprint is reduced by 62%. LED lamps can also have variable light output by reducing the power, allowing even more energy savings compared to fluorescent tubes. It’s the contrast in light output with the surroundings that is important for attracting flies, so, at night and in low light levels, the power and the output of the LED lamps can be reduced while still effectively attracting flies.
Lumnia units also have day and night modes to further reduce the consumption of power when they’re least needed, allowing businesses to save more and lower still their environmental footprint.
The standard fluorescent tubes used in insect light traps only last for about one year before needing to be replaced. During that time, the output of UV light drops to only half of the original brightness. LED lamps produce UV light for a minimum of three years and the brightness only drops to 70% of the original output.
So not only do the LED lamps last three times that of fluorescent tubes, saving on replacement costs, they maintain a higher output of UV light over that period, thus staying effective for longer. The UV output of LED lamps is about 80% greater than the conventional L3 fluorescent tubes used in ILTs. This means that even after three years of use the UV output of LEDs is equivalent to a new L3 fluorescent tube.
No hazardous chemicals
Fluorescent lamps require a number of hazardous chemicals in order to operate and, therefore, if mishandled, are a safety risk. They contain low-pressure mercury vapour – which generates the light when an electric current passes through it – and other gases such as argon, xenon, neon or krypton to control this process. The inside of the glass tube is coated with a fluorescent substance made from various metallic and rare-earth phosphor salts to convert the UV light produced by the mercury into the desired wavelengths. The lamp also has tungsten electrodes that are coated with barium, strontium and calcium oxides to improve their function.
An LED lamp, on the other hand, has a tiny semiconductor wafer encased in plastic. Several of these are placed on a plastic or metal strip to create a lamp that is used in an ILT. There are no hazardous chemicals that can escape into the environment in normal use.
A fluorescent tube consists of a fragile glass tube that contains the mercury vapour and the other components mentioned above. The glass tube can easily shatter if dropped or receives an impact, which would scatter glass and all the chemicals in the tube around the area where food is handled.
In an LED lamp, there is no glass that can shatter and no hazardous chemicals in a form that could be scattered in a food-handling area. In tests in which an LED ILT is dropped repeatedly, the lamps do not break, so they are perfectly safe for a food environment.
With some traditional electric fly killers, flies are zapped and their fragments can escape into the environment, leading to contamination risks in food-handling areas, for example. Lumnia units for high-dependency areas are designed to specifically overcome this by using powerful glue boards or an encapsulation module that captures flies and prevents the insect fragments from blowing out. These minimise the risk of cross-contamination, making fly-control more hygienic.
When compared to traditional fly-traps, Lumnia LED ILTs are not only just as or more effective, they’re more cost-effective, sustainable and hygienic. However, it’s the Lumnia range from Rentokil that boasts a greater reach and catches flies faster than any other LED ILT. And with their modern design, they’re aesthetically pleasing enough to go into front-of-house locations, too.
Find out more about the Lumnia range of LED ILTs.
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