The spotted lanternfly (SLF) has become an increasingly familiar and frustrating pest for homeowners, property managers, and PMPs in parts of the United States. This eye-catching invasive planthopper was first identified in the US over ten years ago in Pennsylvania and has continued to expand its range since. Today, the USDA reports that established populations have been found in 19 states and the District of Columbia.
For PMPs, spotted lanternflies present a unique challenge. Customers may see large numbers of them clustered together on trees, structures, vehicles, or other surfaces and understandably want them gone. But effective management requires an integrated approach that combines multiple pest management tools, including inspection, monitoring, vegetation management, destruction of egg masses, and insecticide applications when needed. SLF has multiple life stages that attack plants, a broad host range, and with the help of humans, will readily spread to new areas while hitchhiking on cars, equipment, and other items stored outdoors.
If it’s not already on your radar, this is one worth knowing more about. Here are some common questions about SLFs that PMPs should be prepared to answer confidently and accurately should they arise:
Why are SLF classified as an invasive species?
The USDA defines invasive species as plants, insects, or diseases that have been introduced to an area where they don’t naturally belong, and their establishment is likely to pose a threat to that environment or damage to agricultural commodities. Invasive species often make their way to these new places inconspicuously by means of travel, trade, or movement of plant materials. Spotted lanternflies are native to parts of Asia and experts believe they were brought in on imported goods. In many cases, invasive pest populations stay balanced in their native range because other organisms, like predator and parasitoid species, help keep them under control. Without those same natural control species here, these invasive pests can spread fast, where populations can become abundant and challenging to eradicate.
What makes SLF harmful to plants? Do they spread plant diseases?
Spotted lanternflies use their piercing-sucking mouthparts to puncture plants and feed on the sap within their tissues. This damage can cause stress, weakening the plants they snack on. While SLF is not known to spread any disease-causing pathogens, they still can compromise the overall health of the plant, leaving them more susceptible to other pests. Additionally, spotted lanternflies produce a sugary substance called honeydew which can lead to sticky surfaces, sooty mold growth, and nuisance pest problems around infested properties.
What kind of plants would I find SLF on? Are there specific plants they prefer?
SLF aren’t very picky and have been observed feeding on a wide variety of plants including important crops like grapevines and fruit trees. With over 70 different host plants on their menu, one in particular, the tree-of-heaven (Ailanthus altissima) (TOH), is its favorite. Like the SLF, the tree-of-heaven is also classified as an invasive species by the USDA. Scouting your property for TOH and other host species is important to determine which plants SLF may be feeding on for targeted management.
What do their eggs look like? What should I do when I see them?
Egg masses from SLF are typically around 1 ½ in long and ¾ in wide and can look slightly different depending on if they are freshly laid or not. A new egg masses will look light grey in color, resembling a wet pat of putty or cement. As they age and dry, they darken up and can look like a smear of dull, cracked mud. Physically removing these egg masses can be an effective management tactic. Extension guidance recommends scraping, smashing, or otherwise destroying them before they hatch. Check your belongings for eggs and other life stages before traveling to help stop their spread, especially if leaving a quarantined area or known range of SLF.
If my property is treated, will SLF stay away?
Not necessarily. While applications are effective at killing and controlling SLF, it’s possible that homeowners may continue to see them. Adults are highly mobile and these applications won’t prevent new ones from coming onto the property. Treatment is an important part of managing these pests, but treating one property does not create a permanent or impenetrable barrier against spotted lanternflies. SLF can continually move into treated areas from surrounding vegetation or get brought in while hitchhiking.
What products from CSI can be used to control SLF?
CSI has a few 2(ee) bulletins that allow for applications to control spotted lanternflies, including contact and systemic insecticides. Both Bifen I/T and DuraFlex ZC are contact insecticides that can be used to directly treat nymphs and adults on the plants and trees where they are found. Dominion 2L is a systemic insecticide that can be applied as a soil injection or drench. This insecticide gets absorbed into and moved throughout the plant, killing spotted lanternflies that feed on their sap. SLF is both a plant pest and a significant nuisance pest, and we are proud to help equip applicators with trusted tools in the fight against this invasive species.