Here are a couple of threads that I’ve contributed to, and there may be more.
I seem to suffer a lot of curculio damage when I don’t spray specifically for them while fruit is sizing up, but I don’t believe you need to use a persistent insecticide although you could. This opinion is controversial. I like Pyganic, but it’s expensive. Here’s yet another pyrethrin compound:
Pick the first warm evening after petal fall and spray after the bees have gone to bed when the curculios are walking about.