Why Insect Glue Traps Are Yellow And Blue

Yellow and blue sticky boards are not a design choice. The colours are chosen because different pest groups respond to different wavelengths.

Yellow Boards

Aphids, whiteflies and leaf miners respond strongly to yellow, so yellow boards perform well against these groups.

Blue Boards

Thrips tend towards blue, so blue boards are the correct choice where thrips are the target.

How To Use Sticky Boards

Boards are hung from the seedling stage through to harvest and should be used continuously without gaps. When a board carries a heavy load of insects, scrape it clean with a bamboo strip or another hard object. Fix each board to a bamboo strip and set it vertically in the crop, 15 to 20 cm above the top of the plants, raising the height as the crop grows.

Board Density

For aphids, whiteflies, leafhoppers and leaf miners, start with three to five yellow boards to monitor population density. When catches on the monitoring boards increase, around 30 boards of 25 cm x 20 cm per mu is sufficient. For thrips, start with three to five blue boards to monitor density, then hang around 30 blue boards of 19 cm x 42.8 cm per mu.

Choosing Between Them

Whether yellow or blue, the purpose of the board is the same. Choose according to the pest species present in the field. Using both together gives a better result.