Biorationals an important non chemical alternative to pesticides for management of two spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) on parthenocarpic cucumber grown under protected conditions

Abstract

The use of chemical pesticides to control two spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) in various crops leads to the development of various problems viz., residue in sprayed crop, pest resistance, pest resurgence and environmental pollution. It was necessary to find some microbial biorationals may represent an effective alternative management tactic which is environmentally safer option also. So, during this study entomopathogenic fungi (EPF) and botanical pesticides were tested at different concentrations for the management of eggs and active stages of T. urticae infesting parthenocarpic cucumber grown under polyhouse. Among these biorationals, spray of Neem Baan at 10 and 15 ml/l resulted in significantly higher level of reduction on two spotted spider mite population (88.5 to 91.8% in egg and 86.6 to 90.9% in active stage of mites after 3rd spray, respectively) than with EPF. Among the EPF, Lecanicillium lecanii (Zimmerman) Viegas and Beauveria bassiana Balsamo (Vuillemin) (at 10 & 15 ml/l (82.0 to 87.0% in egg and 79.2 to 84.1% in active stage of mites)) was found to be more effective than Metarhizium anisopliae (Metschnikoff) Sorokin (at 10 & 15 ml/l (77.0 to 82.4% in egg and 76.4 to 80.4% in active stage of mites after third spray, respectively)) in reducing different life stages of T. urticae on cucumber. Results suggest, as Neem Baan 1% spray was found to increase growth and yield of sprayed plant along with controlling T. urticae, it can act as a good alternative for the pesticide spray because spray of pesticide majority time leads to residue problem, pest resistance and pest resurgence problem.