California has a long tradition of using plant based parameters for insect pest management, especially lygus bugs and mites. From the early 1970's when the first plant based lygus management strategies were developed, the technique has evolved into today's sophisticated physiological mapping program. Lygus evaluation has evolved from strictly based on insect numbers to its present state which relates the plant's developmental status to presence of insects. The development of such plant based techniques requires close multi-disciplinary cooperation between agronomy and entomology. While the agronomists have elucidated the growth and development of cotton, the entomologists have quantified lygus distribution within a cotton plant and the rate at which this pest can damage floral buds. This technique has been accepted by pest managers and is especially useful in areas where lygus occur in low but persistent numbers. Such plant based techniques work very well for insects which damage fruit (squares and bolls) but have not been worked out for foliage feeders or honeydew producers.