Pest profile

Grape Phylloxera

Daktulosphaira vitifoliae · Hemiptera: Phylloxeridae[2]

Grape phylloxera are tiny aphid relatives that feed on grape roots and stunt or kill vines; resistant rootstocks are the only fully effective control.[1]

Grape leaf covered with green warty galls made by the leaf-galling form of grape phylloxera
Grape leaf covered with green warty galls made by the leaf-galling form of grape phylloxera. Photo: andrew2285, public domain (CC0), via iNaturalist

How to identify it

  • They're oval to pear-shaped and 1/25 inch or less, bright yellow on healthy roots, visible with a 10X hand lens.[1]
  • Infested root tips swell, turn yellowish and bend into clubbed shapes.[1]
  • Leaf-galling forms, common in the eastern U.S., raise warty green swellings on leaves, sometimes dozens per leaf.[1]

Where it lives

Leaf-galling forms are abundant in the eastern United States. In California, root feeders do the most harm in heavy clay soils of cooler regions such as Napa, Sonoma and Mendocino.[1]

US map: public records from 35 states since 1990 (GBIF).

Biology and life cycle

Young nymphs overwinter on roots and start feeding when soil passes 60 degrees F; females lay up to 300 eggs.[1]

Crawlers spread through soil cracks, on wind, and on boots, tools and cuttings.[1]

There are 3 to 5 generations a year, more in warm regions.[1]

Damage and signs

  • Vines grow slowly with short internodes, pale leaves and nutrient or water-stress symptoms.[1]
  • Secondary fungal infections at feeding sites girdle and kill roots, cutting growth and fruit.[1]

Health risk

It feeds on grapevines only; UC IPM mentions no risk to people.[1]

Control

Prevention

Plant grapes on phylloxera-resistant rootstocks, or in sandy soil, the only completely effective methods.[1]

Sanitation

Clean boots, tools and equipment that touch infested vines, and don't move cuttings from infested plants.[1]

Pesticides

Insecticides are believed to be of little use on home-grown vines.[1]

Common questions

What are the warty bumps on my grape leaves?
Probably galls of the leaf-galling form of grape phylloxera, which is common in the eastern U.S.[1]
Can I spray for phylloxera?
Sprays aren't very effective on home vines; resistant rootstocks are the real solution.[1]

Sources

  1. University of California Statewide IPM Program, “Grape Phylloxera (Pests in Gardens and Landscapes).” ipm.ucanr.edu/PMG/GARDEN/FRUIT/PESTS/grapephylloxera.html (accessed 2026-10-06)
  2. iNaturalist, “Daktulosphaira vitifoliae taxon page (order and family).” www.inaturalist.org/taxa/324587 (accessed 2026-10-06)

Updated 2026-10-14. Built from sourced records. Spot an error? Tell us.