Blue sticky traps provide a simple, pesticide-free way to catch adult thrips around indoor plants and protected crops. However, where and how you position the boards can make a significant difference to the number of insects they catch.
This guide explains how to prepare, position and replace blue sticky traps for the best results.
WHY ARE BLUE STICKY TRAPS USED FOR THRIPS?
Thrips are particularly attracted to blue, making blue glue boards a useful choice when these insects are the main pest affecting your plants.
When an adult thrips lands on the board, it becomes securely caught by the adhesive. Double-sided traps provide a larger catching area and can catch insects approaching from either direction.
Blue sticky traps are particularly suitable for use in:
- Greenhouses
- Conservatories
- Grow tents
- Propagation areas
- Indoor plant collections
- Other protected growing spaces
HOW TO USE BLUE STICKY TRAPS
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SEPARATE
Carefully remove one blue glue board from the pack.
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PEEL
Remove the protective backing from both adhesive surfaces. Hold the trap by its edges to avoid touching the glue.
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POSITION
Hang or secure the trap close to plant height in an area where thrips or plant damage has been noticed.
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CHECK AND REPLACE
Inspect the trap regularly and replace it when the adhesive becomes covered with insects, dust or plant debris.
WHERE SHOULD BLUE STICKY TRAPS BE POSITIONED?
Position each board close to the upper foliage and flowers, as this is where adult thrips are commonly active. The board should be near the plant without allowing the sticky surface to touch its leaves or flowers.
In a greenhouse or larger growing area, spread the traps throughout the space rather than placing them all together. Pay particular attention to:
- Plants showing silvery leaf damage
- Flowering plants
- Young and tender growth
- Propagation benches
- Greenhouse entrances and vents
- Recently introduced plants
Keeping the boards close to plant height makes them more likely to intercept thrips moving between plants. Adjust their height as the plants grow.
HOW MANY BLUE STICKY TRAPS SHOULD YOU USE?
The number required will depend on the size of the growing area, the number of plants and the level of thrips activity.
A small indoor plant collection may only need a few strategically positioned boards. Larger greenhouses or grow rooms will require traps distributed across the entire growing area.
If one board catches considerably more thrips than the others, add further traps around that location and inspect the surrounding plants carefully.
HOW OFTEN SHOULD YOU CHECK THE TRAPS?
Check the boards regularly, particularly when you first notice thrips damage. Frequent checks help you see which areas have the most activity and whether adult numbers appear to be falling or increasing.
The printed grid can be used to divide the surface into sections, making captured insects easier to count and compare.
Replace a board when:
- Much of the adhesive is covered with insects
- The surface has collected dust or debris
- The glue has become wet or contaminated
- The board is damaged
- It is no longer catching effectively
CAN BLUE STICKY TRAPS REMOVE A THRIPS INFESTATION?
Blue sticky traps catch flying adult thrips and can help reduce the number able to move between plants and reproduce. However, they do not catch eggs inserted into plant tissue or every immature thrips feeding on the plant.
For an established infestation, combine the traps with regular plant inspections and suitable control measures. Remove badly damaged leaves or spent flowers where appropriate and check neighbouring plants for signs of activity.
If you use a plant-protection product, make sure it is suitable for the affected plant and target pest. Always follow the product label.
SHOULD YOU USE BLUE OR YELLOW STICKY TRAPS?
Blue traps are the more targeted option when thrips are the main problem. Yellow sticky traps attract a broader selection of flying plant pests, including whitefly, fungus gnats and flying aphids.
If several different pests are affecting the same growing area, using both colours can provide broader coverage. Position each trap close to the plants without allowing the adhesive to touch the foliage.
COMMON POSITIONING MISTAKES
- Placing every trap in one part of the greenhouse
- Positioning the boards too far above or below the plants
- Allowing leaves or flowers to stick to the adhesive
- Leaving traps in place after the surface is covered with debris
- Using sticky traps without inspecting the plants themselves
- Placing them where water or irrigation spray can reach the adhesive
FREQUENTLY ASKED QUESTIONS
Do blue sticky traps contain pesticide?
No. The traps catch insects physically using a high-tack adhesive and do not need a pesticide or chemical insecticide.
Do blue sticky traps attract thrips?
Yes. The blue surface is particularly attractive to thrips and encourages flying adults to land on the adhesive.
Can blue sticky traps be used around houseplants?
Yes. They can be positioned near houseplants, provided the adhesive does not touch the leaves and the trap is kept away from children and pets.
Can blue sticky traps be used outdoors?
They are best suited to indoor and protected growing environments. Using exposed sticky traps outdoors may result in beneficial and other non-target insects being caught.
How long does a blue sticky trap last?
This depends on the conditions and the number of insects present. Replace the board when the adhesive becomes covered, dusty, wet or contaminated.
