Cucumber and muskmelon very susceptible but squash, pumpkin, and gourds can also contract the disease.
Initial symptoms appear as individual leaves drooping.
These leaves may recover overnight only to wilt during the next day. Eventually the whole plant wilts, turns brown and dies. There is a good diagnostic field test for this disease. Cut a plant near the crown and squeeze sap from the newly cut stem. Heavily infected plants will ooze a milky sap from the cut stem.