Hi, Kate,
Would you say the infestation is severe? If so, it is best to remove and destroy the plants. If not, continue to remove infected leaves and then remove badly infected branches in winter. This will get rid of ovewintering adults and will encourage new growth in spring. If you think insecticide is needed, it can only be used once a year - best to use in late spring when damage is first detected. Using it now will deter some of the pests that might still be in nymph phase, but it will be too late to really control this season.
Kathy C
Replied: Monday 27th of June 2011 08:14 PM