How to Kill and Prevent Spotted Lanternflies
The spotted lanternfly is potentially one of the most destructive invasive insects to ever reach the United States. Entomologists believe this Southeast Asian planthopper entered the country in 2012 as egg masses on imported stones.1
Following its 2014 discovery in Berks County, Pennsylvania, the spotted lanternfly's current U.S. range expanded from Pennsylvania into neighboring Northeastern states. Scientists estimate the spotted lanternfly's potential range, if left unchecked, may encompass most of the eastern United States and the Midwest, as well as the Pacific coast.
Understanding and Identifying Spotted Lanternfly Life Stages
Scientists are still learning how the spotted lanternfly lifecycle manifests in North America. Current infestations consist of one generation per year. The pests overwinter solely in the egg stage. Baby lanternflies hatch as nymphs, not larvae, then pass through four stages or "instars" before becoming adults. They molt and grow larger with each life stage.2 Juvenile and adult spotted lanternfly stages are very distinctive:
- Early or black-stage nymphs comprise the first three instars. Sometimes mistaken for ticks, the nymphs start hatching in mid-spring and mature into midsummer. Their wingless black bodies and legs have bright white spots. Third instar nymphs grow up to 1/4 inch long.
- Late- or red-stage nymphs, seen from early summer into mid-fall, are the final instar before adulthood. Shaped like early nymphs, their bodies are brilliant red with black patches and bright white spots. They grow up to 3/4 inch long.
- Adult spotted lanternflies, often mistaken for moths, measure approximately 1 inch long. They're seen from midsummer until late fall's first killing freeze. Their pinkish-tan, black-spotted forewings are tipped with a black, brick-like pattern. Hindwings, typically hidden, are black and white with black-spotted patches of bright red.
- Egg masses start appearing in late summer and early fall. Fresh masses measure about 1 inch in length and have a waxy, putty-like appearance. Older masses look like patches of dried mud. Underneath the surface, masses hold four to seven columns of up to 60 seed-like eggs.
Monitoring and Recognizing Spotted Lanternfly Damage
Spotted lanternflies damage plants during all stages, from wingless first instars to winged adults. Their piercing-sucking mouthparts penetrate plant tissues, then suck vital sap from the plant. The beak-like mouthparts of black-stage nymphs can't pierce woody tissue, so they concentrate on new plant growth such as tender stems and leaves. Red-stage nymphs and adults can penetrate tree bark.
Spotted lanternflies are known to feed on more than 70 plants in the United States, including grapevines, apples, blueberries, lilacs, birch, maples, walnuts and stone fruits such as peaches. Their preferred host is the Tree of Heaven, known by the botanical name Ailanthus altissima. This invasive Asian tree is found in nearly every U.S. state.
These destructive pests congregate to feed in large swarms as evening approaches. With up to 400 adults feeding on a single grapevine,1 the hordes are easily seen as they feed. Because spotted lanternflies feed in such large groups, sap loss is significant. Weakened plants may suffer stunted growth, poor productivity, decreased winter hardiness and premature death.
In addition to direct plant damage, spotted lanternfly infestations significantly damage quality of life for people and animals nearby. As they feed, the pests excrete large quantities of sticky honeydew, which attracts yellow jackets and other insect pests and develops into sooty black mold. In hard-hit residential areas, outdoor surfaces such as sidewalks, patios and lawn furniture may drip honeydew.
Preventing and Controlling Spotted Lanternflies
In Asia, spotted lanternflies have many natural enemies that keep their population in check. Those natural predators don't exist in the United States, so human intervention is vital in controlling these invasive insects and their spread. If you discover spotted lanternflies on your property, report sightings to your local extension office or your state department of agriculture immediately.
Destroying egg masses is an important line of defense. Spotted lanternflies lay eggs on nearly any hard surface, and they hitchhike to new areas as humans move about. Tree trunks, building walls, lawn chairs, landscape rock and vehicles are all potential egg-laying sites, so inspect your property for egg masses regularly. If found, scrape the mass from the surface and destroy the eggs.
To get rid of spotted lanternfly nymphs and adults, target all stages with GardenTech brand's Sevin Insect Killer, available in convenient Concentrate and Ready to Spray formulas. These highly effective products kill spotted lanternflies by contact and provide residual protection that keeps killing new spotted lanternflies — and more than 500 other listed pests — for up to three months*. The non-staining formulas can treat home foundations up to a height of 2 feet, as well as trees, shrubs, flowers, vegetable gardens and fruits.
Early stage nymphs are known to move up and down tree trunks throughout the day, passing back and forth over an area roughly 4 feet from the ground. Targeting those surfaces helps ensure contact.1 Once nymphs reach adulthood, at least one month passes before they lay eggs. Kill new adults before they lay eggs and you will prevent fresh damage next year.2
By doing your part to kill and prevent spotted lanternflies, you can help limit their damage and stop their spread. GardenTech and Sevin brands are here to help you protect your landscape and home against spotted lanternflies and other destructive insect pests.
* Except fleas, ticks, and mosquitoes
Always read product labels and follow the instructions carefully, including guidelines for pre-harvest intervals on edible crops.
1. New York State Integrated Pest Management Program, "Spotted Lanternfly IPM," Cornell University.
2. A. Nielsen and G. Hamilton, "Spotted Lanternfly," Rutgers New Jersey Agricultural Experiment Station.
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