The disease can affect all aboveground parts of the plants. It was first described in NY in 1887, and is now found in many cool, temperate parts of North America, Europe, and Asia. A yellow ring appears around the spots. Tiny veins in the spots may remain tan to brown, and can be very visible. Spots on or between veins and can be very numerous.
Elongated spots appear on the petioles and stems.
The tissue of the leaf spots tears easily as it dries, giving the leaf a ragged appearance. When the youngest leaves are infected, they may be stippled with dead and yellowish spots. They may even be bunched into a rosette, resembling virus-infected leaves. The growing tips of young plants, especially melons, can be killed. Fruit may be infected at any stage but is most susceptible when young.