ANR-170, Reprinted May 1998. Patricia Cobb, Extension Entomologist, Professor, Entomology, Auburn University

Controlling Two-Lined Spittlebugs On Lawns

Grass Damage And Hosts

Spittlebugs damage grass by piercing the plant tissue with their needle-like mouthparts and sucking out sap. Spittlebug nymphs surround themselves with a mass of froth (spittle) close to the soil (Figure 2).

Damaged grass becomes wilted, turns yellow, and then browns and dies. These damaged areas may start out as wilted or yellowed patches 2 to 4 inches in diameter. Yellowed areas resemble grass affected by iron chlorosis. In heavily infested turf, these small areas may blend so that the whole lawn appears off-color.

Plants commonly infested by adult spittlebugs include hollies (especially Japanese holly), wild grasses, aster, blackberry, pea, and morning glory. Spittlebug nymphs have been reported as damaging a variety of ornamental plants, coastal bermudagrass, and weedy grasses.

Lawn grasses damaged by spittlebugs include St. Augustinegrass, zoysiagrass, and bermudagrasses. Centipedegrass is also damaged; however, damage seems to be more severe than in other grasses. Damage to lawn grasses usually begins in June and continues through August or early September.

Description And Life Cycle

Two-lined spittlebugs overwinter as eggs in hollow stems, behind leaf sheaths, and in plant debris on the soil. Eggs require high humidity for developing and hatching. Nymphs hatch in May and early June in most of the South.

Newly hatched nymphs move around and begin feeding in humid, sheltered places, usually deep in the turf. Each feeding nymph soon produces a frothy mass of spittle which protects it from drying and from natural enemies.

These wingless nymphs resemble adults in shape but they are smaller and are off-white, orange, or yellow with red eyes. After feeding for about a month and going through four nymphal periods, two-lined spittlebugs become adults.

Adults are most active in early morning. They spend the warmer hours of the day deep in turf or foliage. They live for about a month and females deposit eggs during the last two weeks of this time. There are two or more generations a year and there is usually some overlap between these generations. Eggs laid in midsummer will hatch about two weeks later. Those laid in late summer or early fall go through the winter in this stage.

Spittlebug Damage And Humidity

Humidity is the major factor for the development of two-lined spittlebug populations on turf. Eggs and nymphs require a moist, humid environment for growth and development. Humidity is conserved when eggs are deposited deep in the turf and nymphs develop masses of spittle.

Humid weather conditions in the Southeastern United States during most of the period between May and September, as well as regular turf watering procedures, also provide needed moisture. Under these conditions, thick turf and thatch are a perfect combination for retaining moisture at a level deep within the turf where damaging spittlebug nymphs are located.

Diagnosis And Control

An abundance of adult spittlebugs on ornamentals and lawns may result in an infestation that meets the thatch and moisture requirements necessary for egg and nymph development. However, control of adults has not yet been shown to be effective. Lawns heavily infested with spittlebug nymphs may feel squashy when walked on, as if shaving foam were underneath. This sometimes occurs before yellow spots appear in the grass.

Be sure a proper diagnosis is made before spittlebug control efforts are begun. Examine these areas or wilted spots for nymphs. Remember, spittle masses are usually located deep within the grass or in the thatch. Open the spittle masses to reveal the nymph, feeding head down.

Thatch control is important in preventing and controlling spittlebugs on lawns. Proper dethatching and fertilization practices can disrupt the humid conditions essential for spittlebugs.

When treatment is required, mowing before application may also aid in control. Collect and destroy all clippings. If possible, irrigate turf after mowing. Do this several hours before making an insecticide application. Treat late in the day. Once treatment is done, delay mowing for several days.

Control spittlebug infestations chemically with diazinon 25EC or acephate (Orthene Turf, Tree and Ornamental Spray), 8 fluid ounces per 1,000 square feet; or chlorpyrifos (in less thatchy lawns) 22.4EC, 1.5 fluid ounces per 1,000 square feet. Water as required by label directions. Never apply pesticides for the treatment of plants or sites not listed on the label. Apply sprays in 6 to 10 gallons of water per 1,000 square feet, depending on the thickness of the turf. Reinfestation from surrounding lawns or other areas may occur.