Aphids suck plant juices and coat the leaves with sticky honeydew. Use sprays of malathion, Sevin, or rotenone. The insects can also be dislodged with high pressure water sprays from the garden hose.
San Jose scale infests the stems of snowberry. Sprays of dormant oil kill overwintering stages and are less harmful to predators that help control the scale. Sprays of Sevin control the crawlers. The preferred method of control involves regular inspection for early detection of the infestation then spraying with dormant oil.