Dead spotted lanternfly at the base of a treated tree. Photo by Pennsylvania Department of Agriculture
Black walnuts in the wild or in people’s backyards can be treated for spotted lanternfly with insecticides registered for homeowner or ornamental use according to the label directions. This requires homeowners to be properly equipped, to use personal protection equipment if it is required by the label, and to follow all appropriate label restrictions. Homeowners should use homeowner/residential use products and leave commercial ornamental-labeled products to professional applicators that are better trained and equipped to prevent misuse of products that could be more dangerous. The products and active ingredients we have tested at Penn State and are recommending to you in this bulletin are legal to use on any ornamental trees such as tree of heaven, black walnut, some maples etc. that are being damaged or infested in your backyard.
Professional applicators wishing to apply insecticides for spotted lanternfly control on black walnuts in backyards and in the wild can regard these as generic ornamental trees. This is the case for all types of applications, including foliar application, trunk banding, or tree injection. Products that are classified as Restricted Use can only be applied by licensed applicators and it is illegal for vendors to sell Restricted Use Products to non-licensed purchasers. Unfortunately, some products may be available for purchase on the internet and the use of such products by non-licensed applicators is illegal and a violation of the label. Although not required, we recommend that commercial applicators who apply insecticides to black walnuts may wish to post signs with the type of insecticide and date of application that contains a warning to not use the nuts for human consumption.
Farmers (even small-scale or hobby farmers) who have their pesticide applicators license and would like to treat their backyard wild walnuts also have legal access to effective commercial grade products, as long as the product is also labeled for commercial walnuts and label directions are followed. In this case, the walnuts could be used for human consumption. Most of the products currently being evaluated for spotted lanternfly by Penn State are those registered on grape and tree fruits for other pests. As we develop more SLF efficacy data, manufacturers are adding amendments to existing labels for various crops to include SLF, and we will notify the public as soon as they become available.
Care should be taken to avoid insecticide applications or spray drift when ornamentals are blooming and to avoid residues where bees are actively foraging. In addition to residues on the leaves and flowers from foliar applications, some insecticides may be absorbed into the plant and moved systemically through the vascular system into the nectar and pollen, so follow label restrictions to reduce impact on pollinators.
This statement has been produced with assistance from the Office of Pesticide Programs US EPA, the USDA-Office of Pest Management Policy and the Pennsylvania Department of Agriculture.