CONTROLLING WHITE PEACH SCALE ON 'HORT16A' IN ITALY

The white peach scale (Pseudaulacaspis pentagona) (WPS) is a serious pest of Actinidia chinensis 'Hort16A' fruit in the Latina region of Italy. It was responsible for an estimated 10–20% loss of marketable fruit from the region in 2004. An insecticide spray trial was carried out in 2005 to investigate the optimal number and timing of buprofezin and malathion applications. A single buprofezin application in May, applied to coincide with the release of crawlers from the first generation, was as effective as treatment spray programmes which included additional applications timed against the second and third WPS generations. The likely influence of initial WPS population size in spring on the proportion of WPS-infested fruit at harvest was shown by significant block effects. The results suggest that reducing WPS populations with insecticide spray applications during the dormant period, in conjunction with an insecticide application in May targeted at the first generation of crawlers, is important for maintaining low WPS populations on vines during the summer. Buprofezin sprayed on fruit in May left no residue in the fruit at harvest, but buprofezin applied in May and July left a residue of 0.05 to 0.16 ppm.