ventura county nursery implicated in sharpshooter outbreak marin county department of agriculture officials confirmed finding glassy-winged sharpshooters during a routine agricultural inspection. wednesday's announcement identified a shipment of nursery plants from ventura county as the source of the insects. the glassy-winged sharpshooter feeds on grapevines and almond trees by penetrating plant stems and sucking out fluids and nutrients. this can cause loss of vigor, defoliation and eventual death of plants, vines and trees. the pest can suck two to three hundred times its own weight in plant juices each day from a host. the loss of nutrients and fluids is a particular problem during a drought. according to usda, that can amount to 10 to 15 gallons of water per day per tree. we are entering our 5th straight year of drought and the trees are already stressed.
stress makes trees even more attractive to pests. in central valley farming areas about to lose all the state water allocations and will not be able to make up the lost liquids. one of the diseases the sharpshooter carries is pierce's disease, a disease fatal to grapes. marin's deputy agricultural commissioner stefan parnay said, "there's no cure for that, and it will kill the grapevine." pierce's disease has had a devastating effect on california grapes for nearly a century. according to the california department of food and agriculture, the glassy-winged sharpshooter was first reported in california in 1994. it is native to the southeastern united states and northeastern mexico. it feeds on the xylem fluid of a large number of plants. xylem is the plant 'juice' that carries nutrients and water from the roots to the leaves under the outer bark.
in august of 1999, over 300 acres of grapevines infested with the glassy-winged sharpshooter were infected with pd and ultimately destroyed. scientists estimate the host plants for this sharpshooter include over 70 different plant species. among the hosts are grapes, citrus trees, almonds, stone fruit, and oleanders. because of the large number of hosts, glassy-winged sharpshooter populations are able to flourish in both agricultural and urban areas. visit the university of california's or integrated pest management page for options, notes and identification of the glassy-winged sharpshooter.
