Cucumber green mottle mosaic virus (CGMMV) is a plant pathogenic virus. In Europe this virus disease is found since 1965–1975. Watermelon and melon are also susceptible to this virus. Symptoms:The virus affects the young leaves with green and light green spots, even yellow-green spots. These spots have a slower development rate than the rest of the leaf. Sometimes the veins remain green. In heavy infection young leaves are even deformed. The activity of the virus is reduced when the leaf ages. Fruit drop (abortion) is common. The rest of the fruits are small. Yield is reduced by 25% even more if no control action are taken into account. In the epidermis of the sick plants characteristic structures can be seen easily with a microscope.