Growers of cucumbers or cantaloupe are being warned of a pathogen making its way across Virginia. According to the Virginia Cooperative Extension Cucurbit Downey Mildew thrives in warm and humid environments. Your plants might be infected if they have angular leaf spots and yellow spots on top of the leaves. Another warning sign includes fungal growth on the bottom of the leaves. If you think your plants have this disease you should call your local extension agent.