Symptoms of virus infection in a courgette plant, Cucurbita pepo. The picture shows, bottom 2/3rds, a plant displaying typical symptoms of virus infection; the leaves are small, crinkled, and mottled with a yellowish hue. The male flower visible is from the infected plant. At the top of the picture is part of an uninfected leaf from an adjacent plant of the same age. The white markings on the leaf are airspaces beneath the epidermis, a normal feature.The width of the frame is 10cm; only part of the uninfected leaf is shown; it is 30cm long. Members of the cucumber family are prone to a large number of virus diseases, with mottling and distortion of leaves the most obvious symptom. Identification of the specific cause of symptoms cannot be safely made by visual inspection alone.There is no treatment, and affected plants should be removed and destroyed.