Suppressing Pierce’s Disease

Click here for background information on Pierce’s Disease

Blue-green sharpshooters, the insects primarily responsible for spreading Pierce’s Disease in vineyards, have strong natural controls and only occur in low numbers.  There is no benefit in trying to perform additional controls on this insect.

The best way to control Pierce’s Disease is to remove host plants along the creek that serve as the repository for the disease during the winter.  If this is successful, there will be no source of the bacteria when the sharpshooters emerge from the riparian zones in the spring.

The plants to be controlled must meet four criteria.  They are:
1.  The plants must grow in riparian zones.
2.  The plants must be systemic hosts of the Xylella fastidiosa bacterium.
3.  The plants must be attractive feeding sources for blue-green sharpshooters.
4.  The plants must be actively growing when the blue-green sharpshooters move from the riparian zones to the vineyards in early spring.

Even though many species of plants support Xylella infections, only six native and three non-native species meet all of the above four criteria.  They are:

        Native    
    California Blackberry              Rubus ursinus
    California Grape Vitis californica
    Mugwort Artemisia douglasiana
    Stinging Nettle Urtica dioica
    Mulefat Baccharis salicifolia
    Blue Elderberry Sambucus mexicana
  Non-native         
    Himalayan blackberry Rubus discolor
    Periwinkle Vinca major
    Grape Vitis spp.


Services by Pacific OpenSpace, Inc to Suppress Pierce's Disease
Pacific OpenSpace crews are trained in the identification of native and non-native plant species.  They will selectively remove the Pierce’s Disease host plants, in order to remove the source of infection.

Following the site cleanup, Pacific OpenSpace crews will restore the site.  We will install other native riparian species that will not support the spread of Pierce’s Disease.  The result is a healthy native plant and wildlife community that will coexist with your vineyard.