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The appearance and rapid spread of the fall armyworm (Spodoptera frugiperda) (FAW) represents a serious threat to maize cultivation in India and elsewhere in South Asia. Chemical control illustrates one of the major means of reducing the infestation of FAW in maize-growing zones. However, existing information regarding the field-efficacy and non-target toxicity of different insecticides against this pest is not adequate and is also unable to capture the momentum change in the scenario of residual toxicity and insecticide resistance for redacting sustainable management. The present study was framed to establish the most suitable insecticidal schedule against FAW for maize producers. In the period from winter 2019–2020 to spring–summer 2020, seven treatment schedules against FAW were evaluated, and the efficacy was calculated according to the per cent maize plant damage (PD) by larvae, while safety was enumerated based on larval parasitization by Campoletis chlorideae and the abundance of coccinellid predators. In both seasons, the highest cumulative efficacy (9.88 and 10.19% PD) was confirmed for T3 (constituted with Barazide®, Delegate®, and Ampligo®) with a significantly higher yield (52.39 and 52.66 q ha−1), whereas T7 (Proclaim Fit®, Ampligo®, and Delegate®) and T6 (Fimecta®, Ampligo®, and Spintor®) exhibited a high cumulative efficacy (11.06 to 12.23% PD). T3 was found to be safe to coccinellid predators and the per cent larval parasitism by C. chlorideae was significantly higher in this module (2.57 and 2.75%) compared to T4 and T5 (1.00 to 1.67%). The residues of Barazide®, Delegate®, and Ampligo® were below detectable levels in maize plant, grain and soil samples. Therefore, the module could be recommended against FAW in the near future. [ABSTRACT FROM AUTHOR]

Management of the black looper Hyposidra talaca (Walker), the most demolishing foliage feeder of tea in Himalayan foothills, is based on the use of chemical insecticides, though poor field efficacy of various commercially formulated products has recently been reported. In the present study, insecticide resistance of H. talaca to some traditional and newer insecticides was evaluated from north-eastern tea growing belt of India. Six populations of H. talaca were collected in three consecutive years, 2017 to 2019, from five locations (Dooars, Kalimpong, Sikkim, Assam, and Darjeeling). These areas represent the major and commercially exportable best-quality Indian tea production belts. The Darjeeling and Assam populations showed low to very high lethal concentration ratios (LCRs) (16.67 to 140.32, respectively) to bifenthrin, deltamethrin and diflubenzuron while, highest LCR to quinalphos was observed in the Dooars population (119.81). Similarly, very low to extremely high LCRs to emamectin benzoate and flubendiamide (4.00 to 65.25 and 16.43 to 148.94, respectively) were observed in all six populations. However, pyridalyl (LCR ≤ 77.09) and spinetoram (LCR ≤ 82.03) showed higher toxicity than that of cyantraniliprole (LCR ≤ 120.98) to field populations of H. talaca, irrespective of locations. The pairwise correlation coefficients of log LC50 values revealed that emamectin benzoate was significant but negatively correlated with bifenthrin. LCRs to the tested insecticides were heterogeneous and highly variable among locations and years. Specific resistance management strategies should be established, especially in locations where H. talaca has developed very high levels of resistance to newer chemistry insecticides. [ABSTRACT FROM AUTHOR]

Whitefly (Bemisia tabaci Gennadius) is a devastating pest of vegetables, cotton, and many other agricultural and horticultural crops worldwide. Since control of B. tabaci on vegetable crops solely depends on the use of chemical insecticides in India; monitoring the insecticide resistance of B. tabaci populations would be very much essential for achieving successful control and for managing the resistance development. Hence, the aim of the present study was to examine the resistance in different field strains of B. tabaci to traditional organophosphates and new chemical insecticides in India. The resistance ratios were recorded in the range of 30.67-131.48 fold for acephate, 29.17-83.67 fold for triazophos, 0.38-2.51 fold for indoxacarb, 4.55-34.52 fold for dinotefuran, 6.26-27.56 fold for tolfenpyrad, 7.87-31.89 fold for spiromesifen, 1.61-30.08 fold for pyriproxyfen, and 3.09-45.92 fold for flonicamid in comparison to that of the susceptible strain in the laboratory. Resistance levels of B. tabaci populations against the tested insecticides were significantly variable among localities. The present data will be helpful for the selection of proper insecticides on vegetable crops in the field for successful management of B. tabaci in near future. [ABSTRACT FROM AUTHOR]