By Scout Nelson
Aster leafhoppers have been detected in South Dakota wheat fields again this growing season. The insect has become a common sight in recent years and is being observed in both winter wheat and spring wheat. While feeding damage is usually limited, the pest remains important because it can spread aster yellows disease.
Observations and field information shared by Adam Varenhorst, Associate Professor and SDSU Extension Field Crop Entomologist, along with Philip Rozeboom, Patrick Wagner, Brad McManus, and Madalyn Shires, highlighted the importance of monitoring wheat fields for aster leafhopper activity and disease symptoms throughout the growing season.
Aster leafhoppers are small insects measuring about one-eighth of an inch long. They have a wedge-shaped body that is light green to yellow in color and clear wings that cover the abdomen. Adults can be identified by distinct black spots on the front of the head, which is why they are sometimes called six-spotted leafhoppers.
These insects feed using piercing-sucking mouthparts that remove nutrients from plant tissue. Feeding activity causes small white or yellow spots known as stippling. When populations become large, leaves may turn yellow and dry out from the tips. This condition, often called hopper burn, can sometimes resemble drought stress.
Warm weather during May and June can encourage larger populations of aster leafhoppers. Although direct feeding damage is generally not linked to significant yield loss, the insects are capable of spreading aster yellows phytoplasma, a disease-causing organism that affects many crops and weeds.
To transmit the disease, adult leafhoppers must first feed on infected plants and acquire the phytoplasma. After an incubation period of about two weeks, they can spread it to healthy plants for the remainder of their lives. Symptoms of aster yellows may resemble Barley Yellow Dwarf Virus, making careful scouting important. South Dakota wheat fields with aster yellows infections were confirmed in previous seasons, including cases where plants were infected with both aster yellows and wheat streak mosaic virus.
Because no established economic thresholds exist for aster leafhopper management in wheat, producers are encouraged to scout fields regularly, evaluate population levels, monitor feeding injury, and watch for signs of disease development.
Photo Credit: pexels-tudsaput-eusawas
Categories: South Dakota, Crops, Wheat