Potato diseases & insect pests. Artwork of common pests and diseases of the potato plant, Solanum tuberosum. Insect pests of the leaves include the Colorado Beetle (eggs, larva & adult, at upper left), the Potato Leafhopper (at upper right), and Flea Beetles (at upper centre). Diseases of the leaves include Potato Leaf Roll virus (at upper left), Late Blight fungus (at lower left), and Early Blight fungus (at lower right). The underground tubers can be affected by (from left to right): Wireworms, which are the larvae of click beetles; Hollow Heart, caused by the potato growing too rapidly; and Common Scab, caused by Streptomyces scabies bacteria.