Anthracnose, the most important leaf disease of maple, occasionally becomes damaging following several days of wet weather. The first symptoms are scattered, reddish-brown dead areas along leaf veins. These lesions may enlarge rapidly and merge with other spots to cover most or all of the leaf surface (Fig. 75). Dead areas may show irregular zoning and turn gray or black. Severely affected trees may appear scorched. Small, brown fruiting bodies of the causal fungi (the most common one is Aureobasidium apocryptum, formerly Kabatiella apocrypta) confirm the diagnosis of anthracnose and distinguish it from “leaf scorch” caused by drought and heat injury. Control treatments usually are not recommended against anthracnose in sugarbushes.