The DE Department of Agriculture is tracking where the spotted lanternflies are being found; however, they already are aware of them being in Wilmington so there is no reason to contact them with your location specifically.  

I am unaware of any non-pesticide remedies available for successful spotted lanternfly nymph management on small plants.  Sticky bands with wire mesh are available for use with spotted lanternflies feeding on trees.  There are a number of insecticide options available to manage the insects and could include:  shaking them off into a bucket of soapy water, spraying the plant with a broad spectrum insecticide such as Sevin (yes this may have impacts on other insects such as pollinators), or spray the plant with insecticidal soap directly.  Insecticidal soap is a a specific type of soap that is safer to use on plants (less chance of burning foliage).  Insecticidal soap is available at a variety of "box stores" or garden centers throughout the area and has many trade names.  This insecticide has short term residues (less than a day) and only provides control of the insects that it contacts (little chance of harming other insects such as pollinators unless you spray them directly).  This product would probably require repeated use but the impact on non-targets is much better.  

Hope this information is useful and good luck.