Citrus canker is another serious disease in Florida. It is caused by bacteria that infect citrus leaves, stems and fruits, leading to reduced yields. Canker does not kill citrus trees like greening. Canker is transmitted by wind and rain, and it can be made worse by small insects, called leafminers, that feed on leaves. There are some treatments for canker, but the best way to prevent its spread to not move infected citrus to other locations.