The concept of economic thresholds, economic levels and integrated control was introduced by:

Correct option is B

The modern foundation of Integrated Pest Management (IPM) was laid in the seminal paper published in 1959 by V.M. Stern, R.F. Smith, R. van den Bosch, and K.S. Hagen. This landmark work introduced the critical concepts of:
· Economic Injury Level (EIL)
· Economic Threshold Level (ETL)
· Integrated Control, which later evolved into what we now call Integrated Pest Management (IPM)
�� Key Contributions of the 1959 Paper:
1. Economic Injury Level (EIL):
· The lowest pest population density that will cause economic damage.
2. Economic Threshold Level (ETL):
· The pest population at which control measures should be initiated to prevent reaching the EIL.
3. Integrated Control:
· Advocated the combination of biological and chemical control methods.
· Emphasized ecological balance, cost-efficiency, and minimal disruption to natural enemies.
This concept revolutionized pest management, shifting from broad pesticide use to eco-friendly and economically justified pest control strategies.
Explanation for Each Option
(a) V.M. Stern and R.F. Smith (1959) ❌
· Incomplete — omits other co-authors like Van den Bosch and Hagen who were equally instrumental.
(b) V.M. Stern, R.F. Smith, R. van den Bosch and K.S. Hagen (1959) ✅
· Correct answer.
· The full team of scientists who introduced EIL, ETL, and Integrated Control in their 1959 publication.
(c) R.F. Smith and R. Van den Bosch (1967) ❌
· Incorrect year and incomplete author list.
(d) V.M. Stern, R.F. Smith, R. van den Bosch and K.S. Hagen (1967) ❌
· Correct authors but incorrect year. The landmark work was in 1959, not 1967.