Aster yellows disease is primarily spread by which insect?

Aster yellows disease is primarily spread by leafhoppers, particularly the genera Macrosteles and Oncometopia. These insects act as vectors, transmitting the aster yellows phytoplasma while feeding on the sap of infected plants. The transmission occurs when a leafhopper feeds on an infected plant and acquires the pathogen, which can then be spread to other healthy plants during subsequent feeding.

Leafhoppers are particularly effective in this role due to their mobility and prevalence in various environments, enabling them to quickly spread the disease within and between crops. In contrast, the other insects listed, such as fleas, termites, and mites, do not play a significant role in the transmission of aster yellows, making leafhoppers the correct and most relevant choice in relation to this specific disease. Understanding the vectoring role of leafhoppers is crucial for implementing effective management strategies to control the spread of aster yellows in affected regions.