SLF is very susceptible to multiple insecticides. During the fall when adults are very abundant, products with higher residual activity is required. Care needs to be taken if using soil drench insecticides on landscape trees that are important pollen and nectar sources for foraging bees in the spring as the insecticide may still be present in harmful levels.
If you want to use insecticides, make sure you follow all label directions, including the type of plants the material can be applied to, and if it is labeled for plant hoppers.
For low numbers (<500/tree), a solution 1% dish soap and water (i.e. 3 oz. soap in 30 oz. water) can be sprayed onto the plants using a handheld sprayer. Neem oil is also effective against the nymphs. These applications would need to be applied regularly throughout the season.
For nymphs, insecticide options also include products containing carbaryl (follow label instructions)
In areas of high infestation (such as >500 visible SLF/plant), particularly against the adult stage, insecticides can be applied to the trunk such as imidacloprid before July. Dinotefuran can be applied after June. This recommendation is in deference to pollinator protection the following year. Beginning in August adults are typically found in high numbers on tree of heaven, black walnut, sycamore, red maple, river birch, and/or willow. Presence of sooty mold under the tree is a strong indication of an infestation within the canopy.
Dinotefuran soil drenches may be performed July to September to target adults. If your property is highly infested, we recommend contacting landscape/arborists professionals for control applications, njtreeexperts.org.