- Aphids suck the nutrients out of the leaves of shrubbery. Signs that your shrubs are experiencing aphid damage include yellowing of leaves, distorted stems and defoliation. In addition, aphids secrete a sticky substance called honeydew on the surface of stems and leaves. Honeydew will pick up fungal spores that cause sooty mold. Sooty mold is a fungal disease that inhibits the shrub's ability to photosynthesize. When treating a shrub with aphids, spray off the plant to remove the sooty mold. Apply a pesticide to the tops and bottoms of leaves.
- Many types of scale insects exist, but they are broken up into three main categories: soft-bodied, armored and mealybugs. Scales inflict damage by sucking out the nutrients in leaves, roots and stems. You can tell your shrub has become infested by branch dieback, leaf yellowing and defoliation. Left untreated, your shrub can die. Gardeners should prune damaged areas off the shrub to allow for better insecticide contact. Insecticide chemically formulated to kill scales should be applied to the shrub.
- Snail detection occurs at night when the pest is most active. You will see most of the snail damage in the spring and fall or when conditions are damp. These pests like to eat right through the foliage of shrubs. They leave behind damaged or ragged leaves. You can minimize snail damage by pushing back the mulch around your shrubbery. With the mulch removed, the soil around the plant will dry out and provide a barrier. You can also add snail traps to the lawn to help reduce their numbers.
- Leafminers get their name by tunneling or burrowing through leaves. These pests are the larvae of moths, flies or beetles. Shrubbery that has been infested by the pests will exhibit splotchy leaves, discoloration and chewing marks. Because leafminers are protected by the leaf covering, they can be difficult to control. Gardeners can use oils, sprays and dust to control leafminers. The University of Florida recommends gardeners use a systemic insecticide to achieve optimal control.