It may seem early to be worried about insects, but you would be surprised how soon these little pests will be attacking your shrubs.
Scale
These nasty little limbless creatures dwell on the underside of leaves and suck on sap. Once the population of these get to be numerous, they can kill a plant quickly. Euonymus are especially susceptible to these creatures. The best way to control Scale is Dormant Oil in late Winter. This suffocates the larvae before they have a chance to reek havoc on your plants.
Spider Mites
Spider Mites are another devastating nuisance. A sign you may have an infestation is small webs in your shrubs. They are most noticeable in the morning dew. These creatures can kill an expensive Dwarf Alberta Spruce in a few weeks. Again, the best treatment for this pest is Dormant Oil in Late Winter. Just like the Scale, this suffocates the larvae before they can cause damage.