Clubbing of a grape root tip; the tip has become bent and swollen due to feeding of grape phylloxera, Daktulosphaira vitifoliae.

Damaged root tip showing clubbing, 3X. Credit: Jack Kelly Clark
Clubbing of a grape root tip; the tip has become bent and swollen due to feeding of grape phylloxera, Daktulosphaira vitifoliae. Credit: Jack Kelly Clark