assisting wild crops during bug/disease attacks

Hello and welcome! I am very new to this site, and would love to ask you a question about assisting wild crops during bug/disease attacks. I have wild muscadine grapevines and dewberries (blackberry like) here in southeast Texas and both are being decimated. The grapes by caterpillars, and something that is making the grapes wither as babies. Also a rusty-burn on the leaf fungus/disease that I forgot the name of is making the blackberries not be plump and juicy. Is there some way I can combat this? I have skin grade neem oil from a middle eastern store that I use as a pesticide in my garden. I have thought about using that.

Any thoughts would be appreciated.

(If this is in the wrong section, I apologize, and would love moderator assistance to get it in the correct place.)

Thank you!!!

Is this to do with drought? (i.e. the plants are stressed and more vulnerable to insects and disease). Can you work with the plants in their ecosystem in the way you would in a permie situation? eg feed the plants, mulch, change where the water runs when it rains, take water to them etc? This is of course a much bigger ecological problem than just the pests.