The vast majority of modern fly killing devices utilize UV Lamps to attract flying insects. Ultra Violet rays are invisible to the human eye but irresistible to most flying insects. The
UV rays lure flying insects into the killing grids and glueboards, which is a very efficient way of dealing with these pests.
However, the quality of UV light emitted by lamps degrades by approximately 50% each year. This means that after a year the lamp will only be about half as effective as it was when new. After 2 years the lamp will have degraded further and will be operating at about 25% efficiency.
The main issue with this is that to the naked eye the lamps will still seem the same, as humans are unable to see the ultra violet spectrum. A UV detector can be used to gauge what levels
the lamp is currently emitting.
If you do not own a UV detector to check, we recommend replacing your lamps once a year.