Leveillula taurica is responsible spots that for initially pale green gradually appear on the upper surface of the leaves lower of tomato plants. Shaped rounded angular when their outlines are delimited by the ribs of the blade, they turn yellow inexorably over time (Figures 1 and 2). On the underside, opposite the spots, we note the presence of a discreet white down dotting the tissues which are yellowish and show some brown microalterations (figures 3 and 4). The fungus can also sporulate on the surface of leaflets when humid climatic conditions permit (Figure 5).

Eventually, the spots end up necrosis completely and take on a lighter brown tint in their center. More or less concentric patterns are also visible. The macules can coalesce and lead to complete yellowing of the leaf blade and the death of leaflets and leaves, which however do not fall off. Some fruits are no longer protected under the plant cover suffer solar burns .

No symptoms are visible on the other organs of the tomato, including the stem and petioles , as well as the fruits .