The label is the law. Read your product's label before you mix or apply; the rates here come from the labels listed under Sources.
- Active ingredient
- Emamectin benzoate (CAS 155569-91-8)
- Chemical class
- Avermectin; IRAC Group 6 glutamate-gated chloride channel allosteric modulators.[2]
- Mode of action
- IRAC Group 6: Glutamate-gated chloride channel (GluCl) allosteric modulators: avermectins, milbemycins[2]
- Signal word
- Emamectin Benzoate 4.0% Tree Injection: Warning[1]
Protecting ash from emerald ash borer
University of Kentucky entomologists say systemic insecticide treatment is currently the only way to protect an ash tree and must be repeated for the foreseeable future; treat healthy trees you value and remove those with less than half their canopy left.[3]
The label lists adult and larval emerald ash borer under flat-headed borers, at low to high rates, applied to trees whose vascular tissue isn't yet damaged.[1]
Where it is used
Injection sites go into healthy sapwood at the base of the trunk, within 12 inches of the soil or into the root flare, spaced every 4 to 8 inches around the trunk.[1]
Uptake depends on transpiration: apply when soil is moist and above 45°F, air temperature is 40 to 90°F, usually before 2 p.m. Drought- or heat-stressed trees may be injured or poorly treated.[1]
Treat preventively, at least 2 to 3 weeks before pests historically attack. Once galleries or defoliation have damaged the vascular tissue, uniform treatment and control may not be achieved.[1]
Not for trees that yield food for people or animal feed.[1]
Products and registrations
| Product | Registrant | EPA Reg. No. | Active % | Formulation | Signal word |
|---|---|---|---|---|---|
| Emamectin Benzoate 4.0% Tree Injection[1] | Syngenta Crop Protection, LLC | 100-1309 | 4.0% | tree injection concentrate (restricted use) | Warning |
Label rates
| Product | Use | Pests | Rate |
|---|---|---|---|
| Emamectin Benzoate 4.0% Tree Injection | Deciduous, coniferous and palm trees in landscapes, parks and forests | Emerald ash borer and other flat-headed borers, clearwing borers, bark beetles, tent caterpillars, bagworms, spongy moth, leafminers, sawflies and more | 15–1065 mL product per tree[1] Dose is read from a table by trunk diameter at 4.5 feet (DBH) and infestation level: 15 mL for a 4- to 6-inch tree at the low rate up to 1,065 mL for a 70- to 72-inch tree at the high rate. Medium to high rates give longer residual. |
Safety and environmental hazards
People
Signal word WARNING and restricted use due to acute toxicity to humans: it causes substantial but temporary eye injury and is harmful if swallowed. Applicators wear protective eyewear and chemical-resistant gloves.[1]
Pets
The label lists it as highly toxic to mammals; store it away from children and pets.[1]
Bees and pollinators
Highly toxic to bees exposed to direct treatment or residues on blooming trees; don't apply to blooming trees while bees are foraging.[1]
Fish and water
Highly toxic to fish and aquatic invertebrates; not applied directly to water or where surface water is present.[1]
Common questions
- How long does an emamectin benzoate injection last?
- The label says it controls listed pests for up to two years.[1]
- Can a homeowner inject their own ash tree with it?
- No. It is a restricted use pesticide sold to and used only by certified applicators or people under their direct supervision.[1]
- Is it too late to treat an ash tree that's already declining?
- Possibly. The label warns that damaged vascular tissue can prevent uniform treatment, and UK Extension advises removing trees with less than half their canopy.[1][3]
Sources
- U.S. EPA Pesticide Product Label System, “Emamectin Benzoate 4.0% Tree Injection label, EPA Reg. No. 100-1309 (EPA-stamped, Aug. 10, 2022).” www3.epa.gov/pesticides/chem_search/ppls/000100-01309-20220810.pdf (accessed 2026-10-06)
- Insecticide Resistance Action Committee, “IRAC Mode of Action Classification Scheme, Version 11.5 (Feb. 2026).” irac-online.org/documents/moa-classification/ (accessed 2026-10-06)
- University of Kentucky Entomology, “ENTFACT-453: Emerald Ash Borer (EAB) FAQs for Kentuckians.” entomology.mgcafe.uky.edu/ef453 (accessed 2026-10-06)