Dynamics of two spotted red spider mite Tetranychus urticae Koch (Acari: Tetranychidae) in grape vineyards and its co-relation with abiotic factors and a predator

Abstract

Two spotted red spider mite Tetranychus urticae Koch is emerging as key pest of grapes grown in Karnataka recently. Population dynamics studies were under taken in two fixed plots of Vijayapura district viz., Jumnal (Tq: Vijayapura) and Atharga (Tq: Indi) through surveillance to know the status of this new pest. The mite incidence commenced at Jumnal and Atharga from 47th and 45th standard week of November 2012 and continued up to 15th and 17th standard week of April 2013 respectively. The seasonal mean incidence of mites was 13.7 and 14.6 per square inch of leaf in these two villages respectively with higher incidence between January to April months. The correlation studies on population of T. urticae was significantly and positively correlated with maximum and minimum temperature, whereas negatively correlated with relative humidity and non-significant with rainfall.