Raspberries that crumble or have segments that are dry, discolored and deformed may be the outward sign of a debilitating, incurable virus infection. Dig out and destroy affected plants. Do all you can to prevent sucking insects such as leafhopper from feeding on your raspberry plants since these insects vector the disease.
Japanese beetles don't kill a raspberry but can weaken it and reduce the crop or individual berry size. Covering the plants with row cover cloth during beetle season is a simple defense. Like all Japanese beetle control tactics, good timing and daily attention are essential.
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