Houseplant Pests

Aphids

Tiny green, brown or black insect often found on the undersides of leaves and on the buds.

Feeds on plant causing stunted growth, and curled or distorted foliage, produces a sticky sap called honeydew.

Can be controlled by spraying with a strong stream of water or insecticidal soap.

Common hosts: Ornamental peppers, Hibiscus, Mum

Fungus gnats

Small, dark colored flies that jump and fly across the soil. Favoring a moist environment, they cause no damage, but create a nuisance as they develop in potting soil.

Yellow sticky cards can be used to trap adults, also allow soil surface to dry between waterings. Pyrethrin sprays are also effective on adults.

Common host: moist soil

Mealybug

Soft bodies, white cottony appearance on stems, undersides of leaves and on buds, also excretes large amounts of honeydew.

Feeding damage causes stunted plant growth.

Alcohol on a cotton swab can be applied to the bug, caution: alcohol may cause leaf burn. Insecticidal soap and insecticides with pyrethrin are effective.

Common hosts: Jade, Coleus, Lantana, Cactus, Citrus trees, Poinsettia

Mites, Spider mites

Tiny, light-colored arachnids, favor hot dry conditions.

• Produce webbing on foliage and stems, produces distorted yellowish foliage.

• Can be controlled by spraying with a strong stream of water, insecticidal soaps or horticultural oil.

• Common hosts: Ivy, Dracaena, Figs, Hibiscus, Norfolk Island Pine and Schefflera

Scale

Oval or round, brown insects, found on stems and leaves.

Suck plant juices resulting in poor or stunted plant growth, produces sticky honeydew.

Horticultural oil, or handpicked if few in number.

Common hosts: Ficus, Citrus, Ferns, Ivy

Thrips

Extremely tiny insects, adults are light tan to brown, appear white when young, recognized by the damage they cause.

• Feed on foliage and flowers, causing them to become distorted and discolored, create silvery areas on leaf surface, and scarring of petals. May transmit viruses.

• Yellow or blue sticky traps may attract adults. Difficult to treat when inside the plant parts, exposed thrips may be controlled by soaps and oil sprays.

Whitefly

Small, white, gnat-like insect.

• Adults and young feed on leaves, causing the leaves to turn pale yellow or white.

• Yellow sticky cards can be used to trap adults, insecticides containing pyrethrins is effective on adults, horticultural oil, neem insecticides and insecticidal soaps are useful on nymphs.

• Common hosts: Ivy, Lantana, Verbena, Hibiscus, Poinsettia, Tomato, Cucumber

Credits:

W.S. Cranshaw - Colorado State University Extension

Mary Concklin and Kathleen M. Kelley - Consumer Horticultural Center at Penn State

#Aphids #Fungusgnats #Mealybug #MitesSpidermites #ScalePest #Thrips #Whitefly