In addition, the beetles are vectors of the organisms that cause bacterial wilt, which can be more damaging then the insect. The beetle is abut 6mm in length, yellowish green with 3 black longitudinal stripes. The adult passes the winter in shelter of plant debris. That is why rotation works. If you put your cucurbits back where they were last year the cucumber beetle is there to jump on them.
Row covers work, especially to keep pests of the very susceptible seedlings.
But, remember to lift the covers to weed and when flowering starts take the covers off for pollination. Covers of course will not work if you put the cucurbits right back in the same spot as last season. When they find you you will have to turn to the big guns. Pyrenone or pyronyl are the two products that I know work best. Spray very early in the morning when the beetle is inactive in the cool air.