Manisha Yadav, Krishna Rolania, Ankit Yadav and Deepika Kalkal
Abstract
The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a most notorious pest of many agricultural and horticultural crops. The present investigation was carried out to understand the occurrence of whitefly and its natural enemies during Kharif 2021 at, CCS Haryana Agricultural University, Hisar (Haryana). Three cotton cultivars Desi (HD 432), American (H1098i), Bt cotton (RCH773BGII) were sown. The population of whitefly (adults/4 leaves) remained below ETL in June-July and crossed the ETL in the month of August. In all cotton cultivars, the highest population of whitefly adults was observed during 34th SMW (3rd week of August) in Bt (3.98 adults/leaf), American (2.78 adults/leaf) and Desi cotton (2.37 adults/leaf). Similarly, the highest population of nymphs was observed during 35th SMW (4th week of August) in Bt (33.04 nymphs/leaf) followed by American (30.69 nymphs/leaf) and Desi cotton(27.41nymphs/leaf). Among natural enemies, predators like spiders and coccinellids were the dominant. Maximum parasitization of whitefly nymphs was observed in Bt (32.13%) followed by American (20.21%) and minimum in Desi cotton (16.34%). Our study recorded that the population of whitefly was maximum on Bt cotton followed by American and then Desi cotton. The weather parameters such as temperature (maximum and minimum) and average wind velocity influenced the buildup of whitefly and its natural enemies population in all three cotton cultivars.