Aphids are small plant lice. Aphics may be green or black. They suck the sap out of leaves and stems. To control, spray Orthene or a similar product, Mid-Summer to prevent infestation, or when insects appear. Another good solution is to introduce & encourage ladybugs. They eat aphids. An easy, and fun, way to do this is by erecting a ladybug house near the garden.
Borer is a general term, for a varied species. Most borers are larvae of beetles or clear-winged moths. Pin-point holes in tree trunks. Branches will turn yellow and die. best time to control borers is when adult are laying eggs on or under bark. Pheromone traps, available for some borer species, help determine if adults are present. Trunk sprays can be effective when borers are in the early larvae stage before they enter the tree.
As with any treatment plan, look carfully at your pest. Determine exactly what you are working with. Cautiously read the entire label of any product that you use. Be sure that what you are using is safe for your plant. Know the name of the plant you are treating. Many products will treat a multitude of pests, and plants. Some will treat insects, and disease, at the same time.