Green vegetable bug / stink bug (Nezara viridula) questions/control

Hello guys!

Today I've seen this type of stink bug for the first time (zone - Romania). During midday I was checking the blackberries and I saw a handful of insects on a few leaves (both on blackberry leaves and a bindweed's). I thought they were just some native species hanging out, but after identifying them online, turns out it's not the case.
The orchard is relatively small and for the last 5-6 years pesticides/herbicides have been moderately applied, but this year I managed to convince the owner to let me manage it. Surprisingly, even after the immediate cessation of pesticide usage, aphids have been virtually neutralized from the whole orchard, especially by the ladybug larvae.

Now, back to the stink bugs, what's the best way to deal with those? I searched them up online but not many things come up. Are there any natural predators that would get the job done in my region or should I instead deal with them personally? Any tips on making it harder for them to survive winter?
Almost all of them were in the third instar. How exactly do they cause damage? I can't find any significant marks on any of the blackberries, most of which are unripe. About 5 meters from the blackberry plant on which I've seen them, there's another one which is older, bigger and with more mature fruit. No sign of damaged leaves or berries on that one either.

According to Wiki what you photographed is a gathering of immature stink bugs that stay together on the host plant until maturity at 5 weeks of age. Those are 3-4 weeks old.

https://en.wikipedia.org/wiki/Nezara_viridula#Life_history