Comparative Efficacy of Some New Chemistry Foliar Insecticides against Cotton Whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae)

Cotton whitefly (Bemisia tabaci) is known as the most destructive pest of vegetables, ornamentals and cotton including a wide range of weeds, forest trees and semi field crops in the world. Cotton production and area under cotton is continuously declining in Pakistan for the last five years due to a rapid proliferation of the pests. The current study was conducted to evaluate the efficacy of some new chemistry insecticides against cotton whitefly (Bemisia tabaci) during the kharif season of 2019 in a major cotton producing area of Punjab, Pakistan. A total of ten insecticides (single or mixtures) i.e. Dinotefuran + Spirotetramat (T1), Dinotefuran + Spirotetramat (T2), Pyriproxyfen+ Spirotetramat (T3), Pyriproxyfen+ Spirotetramat (T4), Spirotetramat (T5), Spirotetramat (T6), Pyrifluquinazon (T7), Pyrifluquinazon (T8), Flonicamid (T9), Flonicamid + Abamectin (T10) were applied twice in a field experiment on two varieties of cotton (MNH-90 and BS-18) using randomized complete block design. Water (T0) served as control. There were three replications of each treatment. Data for population of whitefly (nymphs and adults), natural enemies and boll weight were recorded 3, 7, 10 and 14 days after treatment of insecticides. Pyrifluquinazon @ 48.7 g/acre (T8) caused the maximum mortality (83%) of adults of whitefly while the maximum nymphal mortality (78.4 %) was observed in T8 (Pyrifluquinazon @ 48.7 g/acre). The maximum increase in boll weight (133%) was observed in T8 (Pyrifluquinazon @ 48.7 g/acre) followed by T10 (Flonicamid+Abamectin) which gave 110% increase over control. The application of Pyrifluquinazon @ 40 g/acre was found to be safer as compared with other tested insecticides with the minimum reduction of 31% in the population of natural enemies. It is therefore concluded that Spirotetramat and Pyrifluquinazon can be successfully included in IPM programs against Bemisia tabaci.