Aster Leafhoppers

Are you seeing speckled leaves? Are leaf veins turning yellow? Are your plants stunted or looking pale? It may be aster yellows, and that disease comes into the garden on aster leafhoppers.

Aster leafhopper (Whitney Cranshaw, USDA Forest Service) CC BY 3.0

Also known as six-spotted leafhoppers, aster leafhoppers (Macrosteles quadrilineatus) prefer cereals and other grasses, such as barley, corn, oats, and rye. They also feed on carrots, celery, cucumber, dill, lettuce, onions, potato, pumpkin and other squash, and radish. Once they have fed on a plant infected with aster yellows, they carry that disease to all the plants they feed on.

Aster leafhopper description

Aster leafhoppers are good at hiding. Before you see them, you may notice tiny insects launching themselves away at your approach. These bugs are only one-eighth of an inch long, narrow, and a dull light green. If you can get ahold of one and take a closer look, you will see that they have six white spots on their heads, but you’ll probably need a hand lens to see that much detail.

Nymphs look like pale, wingless adults. Like their parents, they prefer hiding on the underside of leaves.

Aster leafhopper management

Remove any plants infected with aster yellows to reduce the spread of disease. Aster leafhopper management is tricky. You can use row covers to protect your plants beforehand. You can also use insecticidal soap and horticultural oils to eradicate these pests. Just be careful with those oils in summer because they can increase the likelihood of sunburn damage.