You can squish or stomp out any of the lanternflies you can manage to catch. Some people are even using hand vacuums to catch and kill any that are within reach. However, so many of them are out of easy reach, and they have become widespread in our region now. Killing a few is not expected to make much of a difference in the overall size of the population.

They will not cause serious harm to garden plants, with few exceptions (grape vines and hops, mostly on commercial farms), and we do not recommend using any insecticides on them (which can be harmful to beneficial insects, including ones that prey upon spotted lanternflies). 

Here is our recently updated page with further information:
Spotted Lanternfly Management for Residents

Christa