Yellow and blue sticky traps may look similar, but the colours are used to attract different groups of flying plant pests. Choosing the correct trap can make it easier to catch the insects affecting your plants and identify changes in pest activity.
Yellow provides broad attraction for several common flying pests, while blue is most closely associated with thrips. Understanding the difference will help you choose the most appropriate trap for your houseplants, greenhouse or growing area.
HOW COLOURED STICKY TRAPS WORK
Many flying insects respond to specific colours when searching for plants, food or suitable places to land. Sticky traps use these visual responses to attract insects towards an adhesive surface.
Once the insect lands, the high-tack glue captures and holds it. Traps containing a printed grid also allow captures to be counted and compared over time.
Sticky traps only catch insects during their flying adult stage. They do not control eggs, larvae or non-flying stages already present inside compost or on plant tissue.
WHICH PESTS ARE ATTRACTED TO YELLOW STICKY TRAPS?
Yellow is a highly visible colour that attracts a broad range of flying plant pests. Yellow sticky traps are commonly used for:
- Whitefly
- Fungus gnats
- Winged aphids
- Adult leaf miners
- Other small flying plant pests
Yellow is generally the most practical choice when the pest has not yet been identified or when several different flying insects are present.
WHICH PESTS ARE ATTRACTED TO BLUE STICKY TRAPS?
Blue sticky traps are primarily used for thrips. Thrips are extremely small, slender insects that may cause silvery patches, distorted growth, black spotting and damage to flowers or young leaves.
Blue traps can be useful in greenhouses, polytunnels and indoor growing environments where thrips are the principal concern.
They may catch other flying insects, but their main purpose is targeted thrips detection and capture.
SHOULD YOU USE YELLOW OR BLUE FOR FUNGUS GNATS?
Choose yellow sticky traps for fungus gnats. Position the boards low down and close to the compost surface, where newly emerged adults are likely to gather.
The traps will capture adult gnats but will not affect larvae living in the compost. Review watering, drainage and compost conditions alongside trapping.
SHOULD YOU USE YELLOW OR BLUE FOR WHITEFLY?
Yellow traps are the appropriate choice for adult whitefly. Hang the boards just above or level with the plant canopy and adjust their height as the plants grow.
Inspect underneath the leaves for eggs and immature whitefly, as these life stages will not be caught by the traps.
SHOULD YOU USE YELLOW OR BLUE FOR THRIPS?
Blue traps are usually selected when thrips are the primary target. Position them at or just above canopy level close to susceptible plants.
Yellow traps can also catch some thrips, but blue provides a more targeted option and can make it easier to inspect captures when other flying pests are present.
WHAT SHOULD YOU USE FOR FLYING APHIDS?
Use yellow sticky traps for winged aphids. Yellow boards can capture adults moving between plants, helping reveal when aphid activity begins or increases.
Most aphids remain directly on stems, buds and leaves, so examine the plants as well. Sticky boards will not remove non-flying aphids already feeding on the plant.
CAN YOU USE YELLOW AND BLUE TRAPS TOGETHER?
Yes. Using both colours can be helpful in mixed growing environments where several pest species may be present.
For example, yellow boards can provide broad capture of whitefly, fungus gnats and aphids, while blue boards are positioned near plants susceptible to thrips.
Keep the different traps separated sufficiently so their capture grids can be checked and recorded independently.
WHERE SHOULD STICKY TRAPS BE POSITIONED?
Placement should be based on the target pest:
- Fungus gnats: close to the compost surface
- Whitefly: at or just above the plant canopy
- Flying aphids: around young growth and canopy level
- Thrips: blue traps at or just above canopy level
- Leaf-miner adults: close to affected foliage
Do not allow the adhesive to touch leaves, flowers or developing produce. Adjust the trap height as the plants grow.
HOW MANY TRAPS SHOULD YOU USE?
The number required depends on the size of the growing area, the number of plants and the level of pest activity.
A single board may be sufficient beside one houseplant, while a greenhouse or propagation area will require traps distributed across several locations.
Use the monitoring grid to identify areas with higher captures and add further boards where necessary.
WHEN SHOULD STICKY TRAPS BE REPLACED?
Replace traps when they become full of insects, contaminated with dust or no longer sticky. A board may require more frequent replacement during a heavy infestation or inside a dusty growing environment.
Continue using traps after other control measures have been introduced. A reduction in captures can help show whether flying adult activity is declining.
DO STICKY TRAPS COMPLETELY CONTROL PLANT PESTS?
Sticky traps reduce flying adult numbers and provide useful information about pest activity, but they rarely control every life stage on their own.
Combine them with:
- Regular inspection of leaves and compost
- Removal of heavily affected plant material
- Appropriate watering and plant hygiene
- Biological controls where suitable
- A plant-protection treatment intended for the identified pest
CHOOSING THE RIGHT STICKY TRAP
Choose yellow when you need broad attraction for whitefly, fungus gnats, winged aphids and leaf-miner adults. Choose blue when thrips are the principal target.
If you are uncertain which pest is present, inspect the plant carefully before selecting a treatment. A yellow trap may provide a useful starting point because it catches a wider range of common flying plant pests.
Shop the Yellow Sticky Insect Traps – Pack of 50 for double-sided, poison-free insect capture around houseplants, greenhouses and propagation areas.
