Why AESA based IPM is better than ETL ?

ETL ( Economic Threshold Level ) uses parameters that are constantly changing for calculation of pest population. Farmers cannot make decisions based only on a pest count. Before they can make the best crop management decisions, they must examine many other characteristics of the crop, as well as their own economic and social circumstances. Natural enemies, plant compensatory abilities, and abiotic variables are not taken into account in ETL-based IPM . While in AESA ( Agro-Ecosystem Analysis ) based IPM emphasis is given to natural enemies, plant compensation ability, abiotic factors and P: D ratio.