Aster leafhopper is another insect which carries bacteria with them throughout their entire life. If aster leafhoppers are present in the garden, it is important to remove them as soon as possible. They tend to infect many flowers and vegetables with serious diseases. They can infect the plants with a harmful disease called ‘Aster yellow.’ They infect plants like marigold, lettuce, carrots, onions, beet and many more. The simplest way to avoid this disease from damaging your plants is to remove the aster leafhopper from the garden.