Good weed control promotes rapid drying conditions within the fruiting canopy and discourages populations of insects and diseases that damage the canes and fruit. Each spring when new shoots are about 12 to 14 inches tall, survey black raspberry and blackberry plantings for symptoms of orange rust and viruses. Failure to remove orange rust-infected plants threatens the survival of healthy plants. Problems with sap beetles, wasps, fruit flies and fruit rots will be less severe if the berries are harvested regularly throughout the ripening period so that overripe fruits do not accumulate. Fermenting fruit attracts these pests.
Japanese beetles feed on ripe raspberry and blackberry fruit, as well as leaves.
Remove beetles by hand as much as possible and destroy them. Insecticide liquid lime sulfur Lime-sulfur or copper fungicide for anthracnose, cane blight and spur blight. Lime sulfur for rose scale. This spray is essential for good disease control. If applied to green tissue, damage may occur.