Why Isn't My Insect Light Trap Catching Flies?

The proper placement of an Insect Light Trap (ILT) is extremely important.  Failure to properly position the ILT is probably the single most common reason for lack of control.  Follow the recommendations below to ensure success.


Vertical Positioning

  • 3' - 5' above the floor for most flying insects.
  • Higher placement may be necessary for stored product pests.

Horizontal Positioning

  • In large, open facilities placement at 25' - 50' intervals along the inside of exterior walls is recommended.
  • In smaller facilities, placement near fly entryways and breeding sites is recommended.

General Positioning

  • Placement should not be directly above open food.
  • Place traps as close to likely breeding sites as possible. This includes areas such as garbage and food storage areas.
  • Avoid placement that directs light out doorways or passage ways. Ideally, the light from the trap should not be visible from outside the room in which it is placed.
  • Do not place traps in areas where they can be easily obstructed.
  • Place traps in areas where they will not be easily bumped or easily tampered.
  • Take into consideration air currents caused by doorways, HVAC systems, kitchen hood and other air vents. Strong air currents could lead flying insects into unsuspecting areas.

Best Trap Maintenance Practices

  • Glueboards should be changed monthly if possible. More frequent replacement is recommended in areas with heavy insect pressure.
  • Bulbs should be replaced every 6 to 12 months. Replacement should take place at the beginning of the season when the heaviest flying insect pressure occurs-typically in the Spring.