This form of companion planting can save a target crop from decimation by pests without the use of artificial pesticides.
The number of leaf-to-leaf flights varies according to the insect species and to the host-plant stimulus received from each leaf.
But the insect must accumulate sufficient stimuli from the host-plant to lay eggs; so it must make a certain number of consecutive "appropriate" landings.
Hence if it makes an "inappropriate landing", the assessment of that plant is negative and the insect must start the process anew.
[12] Thus, a clover ground cover was shown to have the same disruptive effect on eight pest species from four insect orders.