Aster leafhoppers are also known as six-spotted leafhoppers, but you’re unlikely to see those spots without a hand lens.
Like other leafhoppers, these insects are fast. They hide under leaves and jump away when disturbed. It may seem easier to just ignore these tiny sap suckers, but aster leafhoppers (Macrosteles quadrilineatus) are vectors for aster yellows disease.
Aster leafhopper damage
As aster leafhoppers feed, they often spread aster yellows disease. Aster yellows is a bacterial disease of carrots, celery, dill, lettuce, oats, onion, potato, radish, rye, and sunflowers. Several ornamentals, such as coneflower, may also become infected. The first symptoms of aster yellows are yellowing veins and leaves that may become twisted, and distorted, sterile flowers. But carrying disease isn’t the only damage caused by aster leafhoppers.
Aster leafhoppers use piercing mouthparts to suck plant juices from leaves and stems. This gives plants a bleached, stippled appearance and it puts a serious dent in a plant’s ability to perform photosynthesis. It also creates points of entry for several other pests and diseases. Adding insult to injury, their excrement creates a habitat for sooty mold.
Aster leafhopper identification
Aster leafhoppers are very small, averaging less than 1/5” in length. They are wedge-shaped and olive green. If you look closely, you will see that the abdomen is yellowish-green and the forewings are grayish-green. If you could hold one still and look through a hand lens, you might be able to see the three pairs of black spots on the head. Wings are transparent. Nymphs look like miniature adults, but they are cream-colored or dark green and they lack wings.
Aster leafhopper lifecycle
These pests blow in on strong winds, usually coming out of the south. Eggs are quickly inserted under the leaf epidermis of host plants and assorted weeds. Eggs hatch in only a week and their lifecycle only lasts four weeks. During that time, they are eating and spreading disease.
Aster leafhopper management
Aster leafhoppers often hide out in weeds such as dandelion, horseweed, pineapple weed, Queen Anne’s lace, and ragweed, so keeping those weeds away from your garden may help. Yellow sticky sheets can be used to attract and capture these and other pests. As always, remove any plants infected with aster yellows disease and toss them in the trash.
Horticultural oil, neem oil, or insecticidal soap can also be used against aster leafhoppers, but they are only effective if the pest is coated with the stuff, which is difficult to do. They tend to move away rather quickly when sprayed. What you can do is use row covers to protect plants from aster leafhoppers. Reflective mulch has been shown to repel leafhoppers.
I hope that aster leafhoppers never blow into your landscape.
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