AHHHH Cucumber Beetle and Squash bugs....the bane to every gardener's existance. Tilling early helps. It opens up the ground for the birds to eat the larvae. Also You could use Diatomaceous Earth. It is a powder that is made of ground fossils. It dries the insects up. Problem is that it takes about 3 days to do so. The best thing that I have found is planting Amaranth also known as pigweed. It is a good trap crop. The beetles love it and migrate to that instead of the cucumbers and squash. You have to be careful not to let it go to
seed because it will become invasive or let it get too tall. The roots on the tall amaranth are very long and deep. Pull it when it gets about 2-3 feet tall. There are lots of ornamental Amaranths in the
seed section at the store...Hot biscuits is one. The nice thing about the trap crop is that you can dust that so that when the beetles land on it they die, but it is not on your edible plants. All that being said, nothing really gets rid of cucumber beetles except systemic poisons and we don't want to go there.