Yes. You can use Dawn dish soap to kill spotted lanternflies at any stage of development. A 50% mix of soap and water can work wonders in a spray bottle against adults, nymphs, and eggs. It can also protect surface water and beneficial insects, since Dawn dish soap does not contain contact insecticides. Just keep in mind that it can be difficult to kill spotted lanternfly egg masses without consulting a professional. There's a good chance you can connect with an extension office in your area to speak with an expert about spotted lanternfly removal. Best of all, this service is free — and you can rest easy knowing you're working on a solution for the adult SLF in your area.