Question

ETL level of Thrips is

• A. 8/leaf
• B. 12/leaf
• C. 5/leaf
• D. 10/leaf

Hint:

The ETL values of major sucking pests in cotton are:
- Thrips: 10/leaf
- Jassids: 1 to 2/leaf
- Whitefly: 6 to 8/leaf
- Aphids: 5% infested plants.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Integrated Pest Management (IPM) relies on the concepts of Economic Injury Level (EIL) and Economic Threshold Level (ETL).
The Economic Threshold (ETL) is the pest density at which control measures should be initiated to prevent the pest population from reaching the Economic Injury Level, where the cost of damage exceeds the cost of control.
Detailed Explanation:
Thrips are sucking pests that feed on plant sap, causing leaf curling, silvering, and transmitting viral pathogens in crops like cotton, onions, and chilies.
In cotton, which is a major cash crop in India, thrips (Thrips tabaci) cause significant damage to young plants.
The established Economic Threshold Level (ETL) for thrips in cotton is 10 thrips per leaf.
When scouting fields, if the average population of thrips reaches or exceeds 10 thrips per leaf across selected sample plants, entomologists recommend applying targeted chemical or biological control measures.
This prevents severe leaf curling, stunted plant growth, and associated yield losses.

Step 2: Final Answer:
The standard ETL level for thrips is 10/leaf.