Spotted Lanternfly (SLF) is impossible to miss in parts of Southern Maryland — adults covering tree trunks, sticky honeydew coating driveways and patio furniture underneath infested trees, and swarms lifting off when you walk past a Tree of Heaven by late summer. If you’re seeing this on your property right now, you’re not imagining an unusually bad year. SLF pressure has been building steadily across our service area, and late summer is when it’s most visible.
I’m Alex Wright, owner of 855TREEMAN and a Maryland Licensed Tree Expert (LTE) #2123. Here’s what SLF actually does to a tree, how to tell if what you’re looking at is SLF, and what genuinely helps versus what’s a waste of a homeowner’s weekend.
What spotted lanternfly actually is
Spotted lanternfly (Lycorma delicatula) is a planthopper native to Asia, first detected in the U.S. in Pennsylvania in 2014. It has since spread through the mid-Atlantic, and Maryland now has active, established populations, tracked and reported by the Maryland Department of Agriculture.
SLF doesn’t chew leaves the way a caterpillar does. It’s a sap feeder — it pierces bark and stems with a needle-like mouthpart and draws sap directly out of the tree’s vascular system. That feeding is what does the damage, both directly and through what it leaves behind.
How to identify spotted lanternfly at each life stage
SLF looks completely different at each stage, which is why so many people miss the early ones and only notice the adults.
Early nymphs (spring through early summer): Small, black bodies with white spots. No wings. Often mistaken for ticks or beetles at a glance because of the size and coloring. These are the hardest stage for homeowners to catch.
Late nymphs (mid to late summer): The same black-and-white pattern shifts to bright red with white spots and black stripes just before the final molt into an adult. This is often the stage that gets people’s attention — the red coloring stands out.
Adults (late summer through fall): About an inch long. Folded wings are light gray-brown with black spots. When they open their wings — whether flying or startled — the hindwings show a bright red patch with black spots and black-and-white banding. This is the stage most people recognize, and it’s the one currently active across our service area.
Egg masses (fall through the following spring): Gray, putty-like coating over rows of eggs, laid on tree bark, fence posts, outdoor furniture, and even vehicles. This is the stage that survives winter and the one most responsible for spreading SLF to new properties — egg masses on a moved vehicle or piece of outdoor equipment can start an infestation somewhere else entirely.
What SLF actually does to a tree
A single spotted lanternfly doesn’t hurt a mature tree. A heavy, sustained infestation is a different story, and it works in two ways:
Direct sap loss. SLF feeding removes sap the tree would otherwise use for growth and energy storage. On a heavily infested tree, especially over consecutive seasons, this contributes to reduced vigor, dieback, and increased vulnerability to other stressors like drought or a hard winter.
Honeydew and sooty mold. SLF excretes a sugary waste product called honeydew as it feeds. Honeydew coats leaves, branches, and anything underneath the tree, and it’s an ideal growth medium for sooty mold — a black fungal coating that can reduce a leaf’s ability to photosynthesize when it builds up heavily. The honeydew and mold combination is usually what triggers the call to us, even before the SLF themselves are the complaint — homeowners notice sticky patio furniture and blackened leaves before they connect it to the insects.
The tree most at risk is Tree of Heaven (Ailanthus altissima) — an invasive species itself, and SLF’s strongly preferred host. But SLF will feed on a wide range of other species when Tree of Heaven isn’t available, including grapevines, maple, birch, walnut, and willow. Fruit trees and ornamentals on a property with an established SLF population are also commonly affected.
What genuinely helps
Remove Tree of Heaven from the property if present. This is the single most effective step available to a homeowner. Tree of Heaven is SLF’s preferred host and its presence tends to anchor an infestation on a property. It’s also an invasive species with no landscape value, brittle wood, and an aggressive root system — there’s rarely a reason to keep it. Removing it doesn’t eliminate SLF from an area, but it removes the reason SLF concentrates on that specific property.
Scrape and destroy egg masses in fall and winter. Each egg mass can hold 30 to 50 eggs. Scraping them into a container of rubbing alcohol or hand sanitizer (not just onto the ground) before they hatch in spring is one of the few actions with a direct, measurable effect on the following year’s population on that property.
Sticky bands on trunks, used correctly. Sticky bands can trap nymphs climbing the trunk, but they need a wildlife-safe mesh cover — uncovered sticky bands catch birds, squirrels, and other non-target wildlife, which is both a welfare problem and, in some cases, illegal. If a band isn’t covered, it shouldn’t be used.
Report significant sightings. If you’re seeing SLF for the first time in an area, or in unusually large numbers, reporting it to the Maryland Department of Agriculture helps the state track spread and target response.
What doesn’t help much
Squashing individual adults. It feels productive and won’t hurt, but it has essentially no measurable impact on a property-level infestation given how many SLF are typically present by the time they’re visible as adults. It’s a reasonable thing to do while you’re outside anyway — just not a control strategy on its own.
Over-the-counter insecticide sprays on mature trees. Broad insecticide treatment on large, established trees is a job for a licensed applicator, not a homeowner with a hose-end sprayer. Coverage on a mature tree’s canopy is difficult to achieve safely from the ground, and treating pollinator-attractive trees with the wrong product at the wrong time can do real collateral damage to bees and other beneficial insects.
When to call a professional
Most SLF situations don’t require removal — they require management. We’d recommend a professional visit when:
- Tree of Heaven is present and needs to be identified and removed safely, particularly if it’s near a structure or property line
- An infestation is heavy enough that honeydew and sooty mold are visibly affecting multiple trees
- A valuable tree (fruit tree, specimen tree, or a tree already stressed from another issue like emerald ash borer) is showing signs of decline alongside heavy SLF presence
- You’re not sure whether a declining tree’s problem is SLF, another pest, drought stress, or something structural — which is exactly what a tree health assessment is for
If SLF pressure has been part of a tree’s decline over a season or two, that’s a case where a proper assessment separates “this tree needs monitoring” from “this tree has a genuine structural problem now, on top of the pest issue.” Those are very different conversations, and it’s worth knowing which one you’re actually having.
Get it looked at
If you’re seeing spotted lanternfly on your property this season and you’re not sure whether it’s a nuisance or something that’s actually hurting your trees, call 855-873-3626 for a free on-site estimate. We’ll identify what’s on your property, tell you honestly whether it’s a Tree of Heaven removal situation, a monitoring situation, or something else entirely, and put it in writing.
FAQ
What does a spotted lanternfly look like?
It depends on the life stage. Early nymphs are small and black with white spots. Late-stage nymphs turn bright red with white spots and black stripes just before maturity. Adults are about an inch long with gray-brown, black-spotted folded wings that reveal a bright red hindwing patch when opened. Egg masses look like gray, putty-like smears on bark or other outdoor surfaces.
Is spotted lanternfly dangerous to my trees?
A few individual insects won’t hurt a healthy mature tree. A heavy, sustained infestation can reduce a tree’s vigor through direct sap loss and through sooty mold that builds up on honeydew residue and interferes with photosynthesis. Risk is highest for Tree of Heaven, grapevines, and trees already stressed by another issue.
What tree do spotted lanternflies prefer?
Tree of Heaven (Ailanthus altissima) is their strongly preferred host. It’s also an invasive species with little landscape value, so removing it when present is usually both a pest-control and a landscape-improvement decision at the same time.
Does squashing spotted lanternflies actually help?
It has minimal effect on a property-level infestation given typical population sizes once SLF are visible as adults. It’s harmless to do, but it isn’t a meaningful control strategy on its own. Egg mass removal in fall and winter has a much more direct impact on the following year’s population.
Should I spray my trees for spotted lanternfly myself?
Broad insecticide treatment on mature trees is best left to a licensed applicator. Achieving safe, even coverage on a large canopy from the ground is difficult, and using the wrong product or timing on trees that attract pollinators can cause unintended harm to bees and other beneficial insects.
When should I call a professional about spotted lanternfly?
Call when Tree of Heaven is present and needs removal, when honeydew and sooty mold are visibly affecting multiple trees, when a valuable tree is declining alongside heavy SLF presence, or when you’re unsure whether a tree’s decline is from SLF, another pest, or a structural issue that needs a full assessment.