Flea beetles like those in the photo below, spotted in a field in Tompkins County, cause only minor chewing damage to corn plants. However, they are a vector for a disease called Stewart's Wilt. Stewart's Wilt is a bacterial disease that affects field corn and sweet corn. Many hybrids are resistant, but Stewart's Wilt can be a big problem on varieties that are not. Early in the season, the disease causes systemic wilt and can result in plant death, and after tasseling it manifests as a foliar blight. The later season blight rarely results in plant death, but can predispose the plant to stalk rot.
If you see flea beetles, you can ask us about your hybrids' resistance levels. And more information about Stewart's Wilt is available from Pioneer at https://www.pioneer.com/us/agronomy/stewarts_wilt_cropfocus.html.