Whitefly (Silverleaf Whitefly) Infestation and Impact on Crops
Life Cycle & Development
- The female whitefly lays eggs on the upper or lower surface of leaves.
- Egg numbers depend on temperature, with 28°C being the most favorable.
- Eggs hatch in 5 to 9 days, progressing through 4 nymphal stages before becoming adults.
- The complete life cycle takes 16 to 31 days.
Temperature & Humidity Influence
- Research at Bikaner Agricultural University found infestation occurs at 7.1°C to 20.5°C.
- The highest infestation was observed at 35°C with 17-55% humidity.
- Pantnagar research showed infestation thrives in 4°C to 42°C with up to 93% humidity.
- Pakistan study on cotton crops found infestation up to 49.7°C and 55% humidity.
- Overall, temperature and humidity impact whitefly growth but do not provide a clear conclusive pattern.
Seasonal Infestation Trends
- Kharif (monsoon) crops: Infestation starts from July to August.
- Rabi (winter) crops: Infestation starts from January to February.
- In tomato crops, whiteflies mainly increase around the flowering stage.
Whitefly as a Virus Carrier
- Whiteflies transmit Leaf Curl Virus in tomatoes and Cucumber Yellow Virus in cucumbers.
- Their lifespan varies based on temperature:
- 18 to 28 days in warm conditions.
- 30 to 48 days in cooler conditions.
- After acquiring a virus, whiteflies can transmit it within 24 hours.
- Once infected, a whitefly remains a virus carrier for life.
Management Strategies
- Timely pesticide spraying during the egg-laying stage can control population growth.
- Crop variety and planting season play a crucial role in reducing infestation.
- Monitoring and early detection help prevent severe crop damage.
Effective management of whiteflies is essential to prevent viral disease outbreaks in crops.
