PROTECT YOUR HIVESSLF CONTROL AND YOUR BEES
SLF does not attack bees — but the chemicals used to kill SLF can. Here is what every beekeeper and pollinator gardener needs to know before anyone treats a tree near your hives.
Which treatments are safe, which are dangerous, what to ask your neighbors to do, and how to protect your nectar sources as SLF spreads.
The Direct Question
Does SLF Directly Harm Bees?
No — SLF Does Not Attack Bees
Spotted lanternfly is a phloem-feeding planthopper. It has no interest in bees, does not compete with bees for nest sites, and does not prey on bee larvae or adults. Direct harm from SLF to bees has not been documented.
The real concerns are indirect — and they are serious enough to warrant careful planning:
Insecticide drift — neonicotinoids in pollen and nectar
Neonicotinoids like imidacloprid and dinotefuran applied to trees can move systemically into pollen and nectar of blooming plants in the tree's canopy or understory. Bees foraging those flowers accumulate sublethal doses that impair navigation, learning, and colony health. Never apply systemics to blooming trees or plants.
Pyrethroids — highly toxic on contact
Bifenthrin, lambda-cyhalothrin, and other pyrethroids are among the most acutely toxic pesticides to bees. A foraging bee landing on treated foliage will die. Residues remain toxic for 24–72 hours after application. Apply only at dusk, never during bloom, and never near foraging areas.
Wasp competition from SLF honeydew
Heavy SLF infestations produce enormous quantities of honeydew — the sticky sugary excretion that rains off infested trees. This attracts yellow jackets and wasps in large numbers. Those wasps then harass bee colonies at hive entrances and compete for water sources, increasing defensive stress on the colony.
Treatment Guide
Bee-Safe SLF Treatment Options
Ranked from lowest to highest bee risk. Mechanical and biological options first — chemical options with clear guidance on safe use where they apply.
Physical Removal
Zero Bee RiskScraping egg masses, step-on kills, clapping adults: no chemistry, no drift, no residual. The safest option for any property adjacent to hives. Start here and do as much as possible mechanically.
Beauveria bassiana (BotaniGard ES)
Very Low Bee RiskAn organic fungal biocontrol that infects and kills SLF through contact. OMRI-listed. Research shows very low toxicity to bees at label rates. Apply in early morning or late evening when bees are not foraging.
Apply when foraging activity is minimal — early morning or after dusk. Avoid applying directly to blooming flowers.
Circle Traps (Mesh Funnel)
Zero Bee RiskMechanical interception traps mounted on tree trunks. No chemical involved — SLF nymphs climbing the trunk are funneled into a collection bag. Zero bee risk. Add a wildlife excluder cage to protect birds and small mammals.
Kaolin Clay (Surround WP)
Zero Bee RiskOMRI-listed particle barrier applied to tree bark. Deters SLF from settling to feed. No systemic activity, no residual toxicity to bees. Used as a bark treatment, not a spray on foliage or flowers.
Apply to bark only — not to flowers or foliage that bees visit.
Systemic Basal Bark — Dinotefuran
Low Risk (if applied correctly)The most effective systemic SLF treatment currently available. When applied as a trunk-only basal bark spray to the lower 5 feet of the trunk, the chemical moves into xylem and phloem — not into nectar or pollen of adjacent plants. September–October application (after bloom season) dramatically reduces bee exposure risk.
Do NOT apply to trees in bloom or to trees adjacent to blooming understory plants. Trunk-only application is critical — no soil drench near hives. Best timing: September–October after bloom season ends.
Contact Pyrethroids (bifenthrin, lambda-cyhalothrin)
High Bee RiskHighly effective contact killers for SLF adults and nymphs, but highly toxic to bees on contact and via residue on foliage. If you must use pyrethroids near hives, apply strictly after dark when bees are in the hive, never within 100 feet of hive entrances, and never to blooming plants or flowering weeds under target trees.
Apply only after dark. Minimum 100 ft from hive entrances. Never apply to blooming plants or flowering weeds. Residue on foliage remains toxic to bees for 24–72 hours depending on conditions.
Critical
What to NEVER Do Near Hives
No imidacloprid soil drench within 300 feet of hives — residual persists in soil and is taken up by clover and other bee forage plants that grow near treated trees.
No bifenthrin or other pyrethroids during daytime hours or near bloom — contact toxicity is immediate and foragers returning to treated foliage will die.
No broad-spectrum foliar sprays on Tree of Heaven when it is in bloom — TOH flowers are a documented bee forage source, and beekeepers in SLF regions value this bloom.
No imidacloprid or dinotefuran soil drench within 300 feet of hives even if the target tree is not blooming — systemic residuals move through root zones and can reach nearby plants bees visit.
The TOH Dilemma
Tree of Heaven (TOH) is SLF's primary host and the tree most beekeepers want eliminated from their property — but TOH flowers produce abundant nectar that bees harvest in June and July. If you kill TOH on your property, plan to replace it with other bee forage trees. Linden, native asters, and goldenrod are strong alternatives (see Nectar Source Recovery below).
Hive Health
The Honeydew Hive Problem
Do Bees Collect SLF Honeydew?
In heavy infestation years, bees occasionally forage on SLF honeydew — especially in late summer and early fall when nectar sources from flowering plants dry up. Bees are opportunistic foragers and will collect any sugar source available.
Honeydew honey from hemipteran insects is well-documented in Europe (fir honey, forest honey). The SLF-specific data is limited, but there is no evidence that SLF honeydew is harmful to bees. The quality of resulting honey is a different question — and likely less relevant to most beekeepers than the wasp competition issue.
Wasp Robbing — The Bigger Risk
The more significant hive threat in heavy infestation years is wasp and yellow jacket pressure. SLF honeydew pooling on leaves, pavement, and outdoor surfaces draws large numbers of social wasps in late summer — the same period when yellow jackets naturally shift toward robbing behavior.
These wasps then target bee hives directly. Smaller colonies and nuc boxes are especially vulnerable. In heavy SLF years, consider entrance reducers to minimum size from August onward, and remove SLF-honeydew-producing trees from the immediate hive yard if possible.
Neighbor Coordination
Protecting Hives During Neighbor Treatments
You cannot control what your neighbors apply — but you can influence how and when they apply it, and how you respond.
Tell your neighbors you have bees before they treat
Most people do not know the difference between bee-safe and bee-dangerous applications. A brief conversation before the spray truck arrives is worth more than any complaint after. Let neighbors know you keep bees, where the hives are, and what you're asking them to consider.
Request dusk-or-later application timing
This is the single most impactful request you can make. Bees are in the hive after dark. Any contact insecticide applied at dusk — even a pyrethroid — has dramatically reduced bee exposure because foragers are not active and residue dries before morning.
Request they avoid blooming plants
Ask that any spray treatment — systemic or contact — avoid applying directly to flowering plants or trees in bloom. This is a reasonable request that most applicators will honor. SLF treatments don't need to hit flowers to be effective.
Move hives temporarily for large-scale treatments
If a large-scale treatment is planned nearby — a neighborhood tree-spraying program, a commercial applicator doing multiple properties — consider moving hives to a temporary site at least 2 miles away for 48–72 hours after treatment.
Propose a no-spray zone agreement
Work with immediate neighbors to establish a 100-foot no-spray buffer around hive locations. This is not always achievable, but many neighbors will agree to avoid spraying close to a hive once they understand the connection.
Forage Planning
Nectar Source Recovery
Tree of Heaven produces significant late-spring nectar that bees forage. As TOH is eliminated from infested regions, beekeepers should plan replacement forage — especially for the August window when SLF adults peak and nectar sources thin out.
Linden / Basswood
June–JulyOne of the most highly valued bee trees in the eastern US. Heavy nectar flow. Plant to replace TOH as a summer nectar source.
Native Asters
September–OctoberFall bloom timing coincides directly with peak SLF adult season. Asters provide critical late-season nectar while you manage SLF pressure.
Goldenrod (Solidago spp.)
August–OctoberPeak goldenrod bloom overlaps exactly with SLF's heaviest adult aggregation. Strong nectar and pollen source — supports colony winter prep at the same time.
Witch Hazel
October–FebruaryUnusual fall/winter bloom when almost nothing else is flowering. Valuable for late-season foraging and the earliest spring flights.
For a broader guide to replacing TOH with native alternatives, see the native plants guide — including species that support both SLF reduction and pollinator forage.
Related Guides
Beekeepers and pollinator gardeners
Know Before They Spray.
Seasonal SLF alerts with bee-safety callouts for treatment windows — so you can protect your hives before your neighbors reach for the spray can. Free weekly.