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

Abstract

The present study was carried out to assess the effectiveness 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. Cotton whitefly is the world's most damaging pest of vegetables, ornamentals, and cotton, as well as a wide variety of weeds, forest trees, and semi-field crops. 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. 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. Pyrifluquinazon at 40 g/acre was found to be safer than other tested insecticides, with a minimum reduction of 31% in natural enemy population. As a result, it is concluded that Spirotetramat and Pyrifluquinazon can be effectively included in IPM programs against Bemisia tabaci.