Seasonal incidence of spider mite, Tetranychus urticae (Koch) (Tetranychidae: Acari) on gerbera (Gerbera jamesonii) under polyhouse conditions

Population of two spotted red spider mite, Tetranychus urticae Koch was recorded on gerbera under polyhouse condition from January 2013 to December 2013. Mite population remained active round the year under polyhouse conditions. The mite population was maximum during last week of July 2013 with 12.86 mites per leaf (2 cm²). The correlation studies between weather parameter and mite population indicated that the mite had non-significant negative correlation with minimum, maximum and average temperature while the average relative humidity at the time of observed had significant positive correlation with mite population. The mite population was maximum on top strata as compared to middle and bottom strata under the polyhouse on gerbera.