GardenSMART :: Spotted Lanternflies are a New Garden Menace
Spotted Lanternflies are a New Garden Menace
By Therese Ciesinski, GardenSMART
Have you heard about the latest invasive insect going rogue in the U.S.? It's the spotted lanternfly, and if you haven't heard much about it yet, you will.
The spotted lanternfly's (SLF) Latin name is Lycorma delicatula. The insect is native to China, Vietnam and Bangladesh. It was discovered in southeast Pennsylvania in 2014. It is found in edge habitats: fragments of land between two types of environments, such as woods and a housing development. SLF feeds on a wide range of plants, including ornamental landscape plants and has no effective predators to keep it in check.
Photographer: Lawrence Barringer, Pennsylvania Department of Agriculture, Bugwood.org
What they look like: Adult SLF look like moths, but are not. They are members of the planthopper family. While they can fly, when disturbed they are more likely to jump. As insects go, they are pretty: Mature lanternflies are red with black spots and white wings and are about 1 ½ inches wide.
Photographer: Eric R. Day, Virginia Polytechnic Institute and State University, Bugwood.org
Life cycle: Females lay eggs on trees and manmade surfaces from September to December. Eggs begin to hatch the following May-June. The nymphs go through four instars (growth cycles) between June and September: in the first three, the nymphs are black with white spots; by the last, they are mostly red. Adults begin appearing in July and continue through September. Late August and early September are when numbers are greatest; they can mass by the hundreds on a single tree to feed.
What they eat: While SLF's preferred food is the invasive tree Ailanthus altissima – tree of heaven – it feeds on more than 70 plant species, including grapes, hops, fruit trees and hardwood trees, putting certain agricultural industries at risk. They suck the sap from plants and leave weeping wounds that attract diseases, and excrete honeydew that can cause sooty mold. Heavy feeding can stunt the growth of plants, weaken and kill them.
Spotted lanternfly's favorite food is Ailanthus altissima, also called tree of heaven, with grapes a close second.
How they spread: Spotted lanternflies are expanding from where they were found in Pennsylvania, not just due to lack of predators, but by their eggs being moved to new areas on trucks, cars, plants, firewood and other items. The egg masses look like dried mud. In addition to trees, SLFs lay eggs on walls, vehicles, rocks, patio furniture; pretty much any hard outdoor surface. When the eggs mature, they look like lines of seeds.
Presently there's a quarantine in 13 southeastern Pennsylvania counties to keep the pest from spreading, but SLF has recently been spotted in New Jersey and counties in PA outside the quarantine area. It's not a question of whether it will spread, just how quickly. Gardeners in northeast and Mid-Atlantic states should familiarize themselves with the pest and its life cycle. Immediately report any sightings to the local state extension service office. Try to capture or photograph the insect for positive identification.
Photographer: Richard Gardner, Bugwood.org
How to control them: In fall and winter, egg masses should be scraped off, collected, double bagged and thrown away. Eggs can be put into alcohol or hand sanitizer to kill them.
Experts recommend placing sticky bands around the trunks of vulnerable trees in spring to capture nymphs massing to feed, however homeowners have reported birds and squirrels becoming stuck on the bands.
Both organic and synthetic insecticides can be used on the nymphs and adults, but methods that are less likely to harm non-target insects, birds and animals are preferred. Spiders and praying mantises will eat SLF, but not in quantities that effectively reduce their numbers.