Determination of the Leaf Consumption by Different Larval Stages of Defoliating Major Tea-pest Hyposidra talaca Walker (Lepidoptera: Geometridae), under the Treatment of a Chemical Pesticide, Emamectin Benzoate and a Biopesticide, Bacillus thuringiensis on the Basis of Leaf Area Parameters

Lopper stages of Hyposidra talaca, the major tea-pest infests the tea leaves in large scale in the tea plantations of Darjeeling-Terai region of West Bengal. This geometrid moth has five instars in their larval stage. In this present study the leaf consumption was measured for last three instar stages of this pest for three consecutive days. It was found that the final instar stage infests most vigorously comparing to other looper stages. The leaf consumption of this black inch looper was also calculated under the treatment of two pesticides- the most widely used chemical pesticide, Emamectin Benzoate and the potential biopesticide for this lepidopteran pest, Bacillus thuringiensis at their field concentrations. Though both the pesticides effectively decrease the pest infestation, however, the chemical pesticide showed better effect on the leaf consumption. But considering the adverse effect of the chemical pesticides on the ecosystem, the equally effective and ecologically safe biopesticide can be an alternative better choice to control this major defoliating pest in the tea plantations.

Saugata Ghosh*1 Click here to download file

Research Article | Published online : 08-Jun-2021