Common Sage Pests

Aphids

• Although aphids usually do not cause massive destruction, large populations can cause unsightly yellowing and distortion to sage's foliage and stunt the growth of new plants, according to the University of California Integrated Pest Management Program. The soft-bodied, pear shaped insects have antennas and long legs. These little green, brown, yellow or red bugs pierce plant parts and in the process leave behind a sticky residue called honeydew. The presence of honeydew occasionally results in sooty mold, which causes further damage to the sage plant.

Mealybugs

• Mealybugs gather on the underside of sage leaves and sometimes in the roots of plants. Damage from the sucking of these white, waxy insects can causes distortion of foliage and lead to the sage plant's eventual death. The presence of cottony-looking areas congregated on a sage plant indicates mealybug infestation.

Greenhouse Whiteflies

• With more than a thousand species, whiteflies have become a worldwide pest problem, according to the University of Hawaii. Greenhouse whiteflies, in particular, exist in the tropics and subtropics, as well as in greenhouses. They are pale yellow in color and have two sets of wings covered with powdery white wax. Whiteflies suck on plant tissue. Damage, while not obvious to the eye, occurs when large groups of whiteflies feed on a sage plant, reducing its vitality. Like aphids, whiteflies also leave behind honeydew, making plants susceptible to sooty mold fungus.

Thrips

• Tiny insects with fringed wings, thrips come in a host of species. Some species are harmful and others are innocuous. In most cases, only experts can identify the harmful ones. Although they have wings, thrips fly poorly, relying on the wind to carry them across distances. Hiding behind furled leaves and inside buds, thrips suck away at sage plant tissue, leaving evidence behind in scarred foliage and tiny black feces. Scarred leaves may become more distorted and turn papery in texture. Thrips may also inject viruses into the tissue of sage plants while they feed, which results in more damage to infested plants.

Pest Control

• If a pest problem breaks out on a sage plant, identifying the pest is the first step in damage control. Once you've identified the pest, you can take suitable measures, either through chemical or biological means. Common chemical means for sage pest control include insecticidal soaps, neem oil and synthetic insecticides.