Which came first, the invasive Tree of Heaven (Ailanthus altissima) or the invasive Spotted Lanternfly (Lycorma delicatula)? And what is their connection? The answer to the first question is the Tree of Heaven, native to China, was first introduced as an ornamental tree in Philadelphia, Pennsylvania in the 1700s. The Spotted Lanternfly (SLF) was first identified in Berks County, Pennsylvania in 2014. It was accidently introduced from Asia and is native to China, India, and Vietnam. Unfortunately, there are no natural predators of the SLF in North America. The Tree of Heaven is the preferred host for this insect during all stages of its life cycle. Homeowners should consider removing this invasive tree and replacing it with a tree native to Maryland; doing so is an easy way to control both invasive species.

SLF eggs are covered in a gray, waxy coating prior to hatching and are found in masses on tree trunks or other vertical surfaces from late September to early May. Eggs usually hatch in late April to early May. All vegetation, structures, and vehicles including RV’s and trailers should be inspected for eggs or signs of the SLF, as movement of vehicles with egg masses contributes to the spread of the insect. The SLF does not fly far but is a hitchhiking pest.

The early stage SLF nymph (juvenile, immature stage) is about the size of a small tick. They are black and covered with white spots including the legs. The late stage SLF nymph is red and black with white spots and is usually half an inch in size. The adult, which can be spotted from the beginning of July, has tan wings with black spots and a brick-and-mortar pattern along the wing tips. The inner wings have a red strip close to the thorax (body). If a resident spots any stage of the SLF, they are asked to report the siting to the Maryland State Department of Agriculture. The online reporting form is at mda.maryland.gov/plants-pests/Pages/spotted-lantern-fly.aspx.

SLF nymphs climb to the top of the trees to feed on sugary plant sap. Using their piercing sap-sucking mouthparts they probe the leaves, stems, and twigs. SLF will also feed on many other species of hardwood trees, including maples, walnut, apple, stone fruit trees, and grapes. SLF are not known to bite or sting humans, but they are a threat to many fruit crop and trees. A SLF infestation can result in economic losses to the agricultural and timber industries. The excretion from adult SLF feeding is called honeydew, which can attract other insects that can cause further damage to the tree. The sticky, sugary honeydew leads to the growth of sooty mold, which further impacts the heath of the tree by interfering with photosynthesis. Sooty mold will also grow on other items that are beneath the tree, such as deck furniture or vehicles.

If a SLF is observed, residents should attempt to eliminate the insect from their property. When a few insects are found, residents are encouraged to control the spread by squishing them. Eggs can be scraped off and put into a container of rubbing alcohol (or plastic zippered bag filled with hand sanitizer) before disposal. Tree sticky bands can be an effective monitoring tool and control method. The sticky bands can be placed around the tree trunk to trap SLF nymphs as they migrate up and down the tree trunks during daily feeding. Removal of Tree of Heaven trees can also help to reduce SLF populations. Insecticidal applications of EPA registered systemic pesticides can be used to control large infestations of SLF. Always read pesticide labels carefully and follow all instructions, including use of safety equipment, mixing rates, use, and safe disposal.

Residents are encouraged to learn more about this invasive insect and be on the look-out for it in our area. A useful checklist to help identify and manage the SLF can be found here: www.aphis.usda.gov/publications/plant_health/fsc-slf-checklist.508.pdf.

From the City's Tree & Landscape Board