Influence of abiotic factors on the infestation dynamics of whitefly, Bemisia tabaci (Gennadius 1889) in cotton and its management strategies in North-Western India

Bemisia tabaci is the most destructive insect of cotton worldwide. We analysed infestation dynamics of B. tabaci in cotton during summers of 2015–2017, and predicted the factors influencing its abundance. The incidence of B. tabaci on cotton was exceptionally high in 2015 (25.91 ± 2.14 adults/3 leaves) as compared to 2016 (9.53 ± 1.23 adults/3 leaves) and 2017 (8.54 ± 1.12 adults/3 leaves). Minimum temperature, maximum-minimum relative humidity and rainfall influencing the B. tabaci population build-up were predicted using PCRA technique with reasonable accuracy (R2 = 0.87). The results also showed that monitoring/ sampling of B. tabaci in cotton should be done before 10:00 h. Among different cotton cultivars, Ankur 3028 and Bioseed 6588 were most susceptible to B. tabaci infestation. Bemisia tabaci incidence in cotton interferes with the secondary metabolite production in different cultivars. Pesticides tested for management of B. tabaci gave a maximum population reduction ranging from 42.91 to 77.01% 7 days after spray. The efficacy of tested pesticides persisted up to 10 days after spray. Maximum control of B. tabaci was achieved by flonicamid > clothianidin > diafenthiuron > dinotefuran > thiamethoxam, whereas, ethion was found least effective. Pyriproxyfen have nymphicidal action and provided maximum reduction (68.62%) in whitefly population after 10 days of spray.