From wikipeda, it sounds like wasps are a natural predator. Not sure which native wasps might go for them or how to encourage that.

Chickens would probably eat them but they might eat your grapes as well.

In my area we've had the Spotted lanternfly for more than 5 years now, maybe closer to 10. In the first year or two they could be seen in huge numbers. Since then they've waned off considerably. Like last year I don't recall seeing many at all. This summer they are back but still nothing compared to that initial wave. I've seen birds eating them, leaving lots of disembodied red wings in my backyard. Feels like they will reach some equilibrium stable population.

I hope your grapes make it through