The plums drop from the tree before ripening. None survive. I also have a plumcot tree that is affected. I don't want the weevils to spread to other fruit trees in my yard. Is there anything I can do in the fall or winter to begin control? I read that bonide was a good spray. Is it?
Do You Have a Spray or Control Schedule for Plum Curculio Weevils on Plum Trees?
While spraying is effective in the spring, fall and winter control consists of cleaning and disposal. https://www.gardeningknowhow.com/edible/fruits/plum/plum-curculio.htm
Since the most effective chemical control is carbaryl, the best product should be the one with the most carbaryl in it. Bonide is more of a broad spectrum product; you can find a number of products with higher concentration by googling "carbaryl."