Aphids, whiteflies, scales, and many other insects initially locate plants on which they feed by using visual cues such as color. However they do not see the colors reflected from the plants in the same way we do. Insects are able to distinguish among the various colors-of light that are reflected from the surface of plants. Therefore, instead of seeing leaves as a green color, they see varying hues of yellow and blue that are reflected from the leaf surface.
The color of reflected light that we perceive as yellow (wavelength 500-600 nm) is a major component of the light reflected from plant surfaces, and a greater amount is reflected from newer growth than older growth.
Most aphids, whiteflies and scales prefer the newer growth and fly towards objects reflecting large amounts of light at the proper wavelength. They will be attracted to any object strongly reflecting light in the 500-600 nm range including plants, shirts or cars. This strong response to yellow colored objects can be used to help control the numbers of aphids and whiteflies in your garden.
Our yellow traps looks like a mass of new foliage to the flying insect and attracts it to the trap where it attempts to land. By covering the trap with a clean, sticky material, you can reduce the population of aphids or whiteflies in your garden. The impact of the traps will be greatest when pest numbers are low in the spring/ early summer.
Our company is producing two different colored sticky traps: yellow and blue.