Phylloxera primarily attacks which part of the grapevine?

• A. Leaves
• B. Fruit
• C. Roots/rootstocks
• D. Bark

Answer: (C)

Phylloxera’s feeding is concentrated in the soil on the vine’s root system, where the pest attacks the roots and can form galls on the fine roots. This underground assault disrupts the plant’s ability to take up water and nutrients, leading to vine decline or death, especially in vineyards using susceptible root systems. Because the primary damage originates in the roots, the roots or rootstocks are the part most affected. Leaves, fruit, and bark aren’t the main targets of phylloxera in grapevines; any issues in those above-ground parts are usually a consequence of severe root damage rather than the primary feeding site. This is why resistance is built into rootstocks to protect the vine from this subterranean attack.