Climatic factors and mite predators influence on the tetranichids mite population in citrus

Abstract

Texas citrus mite Eutetranychus banksi (McGregor), citrus red mite Panonychus citri (McGregor)
and spider mite Tetranychus mexicanus (McGregor) (all Acari: Tetranychidae) are citrus pests that cause chlorotic spots on the leaves, provoke shoots’ death and make leaves and fruits fall. To know the population fluctuation and ecological aspects of these pests a study was conducted from July 2003 to June 2006 in a ‘Valencia’ citrus
orchard situated in Chapecó, Santa Catarina State, Brazil. Biweekly the infestation of these mites was evaluated
in 20 trees counting the number of these mites on three portions of their preferred locations by the use of lenses with increase by ten times and 1cm2 of the fixed field. The results showed that the infestation of the tetranichids mite decreases during periods with more rainfall and high predatory mite incidence, and increases with higher temperature.