What Pesticides Will Keep Bugs Off of Strawberries?

Strawberry Leafrollers

• Strawberry leafrollers (Ancylis comptana fragariae) are a strawberry pest widespread throughout the United States. These greenish-brown caterpillars emerge in April and May laying eggs on the foliage. The larvae mine through the plant leaves, tying them together and skeletonizing them from within the leaf. The leaves turn brown and die, and the strawberry fruit is deformed. Treat heavy infestations with Bacillus thuringiensis kurstaki, or BTK, which produces crystal toxins the strawberry leafrollers ingest while feeding. They become paralyzed, stop feeding, drop to the soil and die.

Tarnished Plant Bugs

• Tarnished plant bugs (Lygus lineolaris) eat herbaceous fruit plants like strawberries. They have oval bodies that are twice as long as they are wide and are about 1/4 inch long. They are brown with yellow and/or red markings that darken with age. They inject a chemical into the fruit while sucking juices from the stem tips, buds and fruits. They cause catfacing the fruits, a sunken, bumpy disfiguration. Tarnished plant bugs overwinter in weeds and dead plant material, so keep garden debris clear and use floating row covers during the growing season. Apply insecticides containing pyrethrins to flowering plants.

Spittlebugs

• Masses of frothy bubbles in between the strawberry plant's leaves are signs of spittlebugs. Meadow spittlebugs (Philaenus spumarius) are the most common type found on strawberry plants. Removing the bubbles uncovers the ¼-inch, green or brown, soft-bodied insects that suck sap from the leaves, stems and flowers. Spittlebugs rarely cause an extreme amount of damage to strawberry plants. They are easily removed with a strong stream of water from a garden hose. Insecticides containing malathion, acephate or methoxychlor are also effective with only one application being necessary.

Spider Mites

• Microscopic reddish-colored spider mites thrive in warm, dry climates. Mottled, dirty, yellowing leaves with fine webbing between the leaves or on the undersides are indications of spider mites. Spider mite infestations cause few strawberries to fruit. Spray an insecticidal soap made with clean water and a small amount of mild dish soap and neem oil onto the plant several times a week. Apply the insecticidal soap either early in the morning in the evening to avoid direct sunlight.

Snails and Slugs

• Slugs and snails are gastropods closely related to clams, oysters and other mollusks. Their gray, brown or black soft bodies move by a broad muscle that spreads along their undersides. A trail of slime indicates their presence. Snails and slugs are night feeders preferring moist, sheltered conditions. They cause extensive damage by ravaging the leaves, stems and fruit off strawberry plants. Pesticides intended for snails and slugs are effective. Organic options include dusting diatomaceous earth, a nonselective dust that dehydrates the pest, onto the soil where snails and slugs are present.

Strawberry Bud Weevil

• Strawberry bud weevils (Anthonomus signatus) are small, dark reddish-brown insects with curved snouts. They are also called strawberry clippers because the females chew holes into the buds, insert an egg and then cut off the bud. One female lays 20 to 30 eggs, usually in April and early May. Cleaning garden debris harboring eggs and overwintering adults controls strawberry bud weevils. Once buds start forming on the strawberry plant, use an insecticide containing pyrethroids or pyrethrin.