Grape phylloxera—Daktulosphaira
vitifoliae
Phylloxera are tiny yellow soft-bodied insects that feed in groups on roots especially in summer and
fall. They are oval and less than 0.10 inch long; a hand lens is required to see them.
Life cycle
Damage
Phylloxera cause a premature yellowing of leaves and stunted growth. Root tips are swollen with yellow
brown galls. Roots may be dead or dying.
Symptoms
There are no satisfactory controls available once vines are infested. Good irrigation and fertilizer practices
help offset damage to roots. Use resistant rootstocks. |