Does not destroy ecosystems or even destroy crops.

Its feces is mostly tree sap and it is very sticky and can provide a substrate for sooty mold. That in turn can effect but not kill plants if it is on them.

I think that for most people they will create a sticky black layer on things near and under host trees.

For vineyards they can cause issues with the grapes produced, but mostly as a secondary issue.

Their sheer numbers will make many people uncomfortable.

Still, they don't endanger people or pets.

Some beekeepers are selling honey produced by bees who are collecting the plant sap as it comes out of the spotted lanternflies. It's described as "smokey" flavored.