Pests 

Brown Marmorated Stink Bug

Halyomorpha halys

An insect in the family Pentatomidae that is native to China, Japan and Taiwan. 

The Brown Marmorated Stink Bug is widespread in Oregon's Willamette Valley and is found in Oregon vineyards. Although this pest does not currently pose an economic risk to winegrapes in Oregon, it is important to be able to identify this pest while scouting your vineyards. BMSB may cause a taint when crushed in winegrapes, and researchers identified the threshold of detection as four BMSB per cluster. However, in Oregon, the highest number of BMSB found on grape clusters is one BMSB per four clusters. Report a BMSB sighting.

Spotted Wing Drosophila

Drosophila suzukii

Spotted Winged Drosophila (SWD) is an invasive pest found in Oregon, California and Washington. SWD infests a variety of fruits including peaches, cherries, raspberries, blueberries, and table and wine grapes. Infested fruits are ruined because the damage caused by fly maggots as they consume the fruit accelerates rotting. SWD favors intact, ripening fruit that is still on the plant, especially late in the season, as opposed to favoring overripe and fallen fruit on the ground as in other drosophilid vinegar flies, makes SWD a pest of concern. 

Mealybugs

Family Pseudococcidae

Mealybugs have been identified as vectors of Grapevine Leafroll Viruses. Virus infected vines often follow patterns of mealybug infestations in a vineyard. Vineyards in Washington, Oregon California, and Idaho have observed the spread of grapevine leafroll viruses since 2002. Below is information about how to scout for vectors of this disease. Prominent mealybug vectors include the grape mealybug (Pseudococcus maritimus), vine mealybug (Planococcus ficus), and obscure mealybug (Pseudococcus viburni).

Disease

Red Blotch

Family Geminiviridae

Grapevine red blotch-associated virus (GRBaV), is a virus associated with the emerging red blotch disease that was described for the first time on Cabernet Sauvignon in Napa Valley in 2008. Although a vector has not been confirmed, there are steps growers can take to mitigate the impact of the disease. When establishing a new vineyard, ensure that plant materials are certified, remove all symptomatic vines from current vineyards, have suspicious vines tested, and if symptoms of vector insects are identified, mark and remove symptomatic grapevines. In addition, growers should monitor for symptoms of vectors including girdling of treehoppers.

Videos and other resources: 

Grapevine Red Blotch Vector Update (website)– October 2016
UC-Davis Research Team working on Three-Cornered Alfalfa Hopper

Integrative Studies of Vector-Related Virus Epidemiology: Red Blotch Situation in Oregon (webinar)– February 2016
Vaughn Walton, Horticultural Entomologist, Oregon State University Department of Horticulture, OWRI

Grapevine Red Blotch - Status of Vector Research (webinar) – February 2016
Brian Bahder, post-doctoral researcher, UC-Davis Dept of Entomology & Nematology

Grapevine Red Blotch – What You Need to Know (webinar)
Presentations on the history, detection, transmission of Grapevine red blotch virus and clean plant sources

Grapevine leafroll-associated virus

Family Closteroviridae

Grapevine leafroll associated viruses are an important group of grapevine viral diseases affecting grapevines worldwide. The impact on vine health, crop yield, and quality is difficult to assess due to a high number of variables, but significant economic losses are consistently reported over the lifespan of a vineyard if intervention strategies are not implemented. Several viruses from the family Closteroviridae are associated with GLD. Mealybugs are a vector for this disease, therefore management of these pests is vital to protecting vineyard health. Mealybugs are a vector of this virus, therefore growers should understand and montior for symptoms of mealybug infestations. 

 

Powdery Mildew 

Pathogen: Erysiphe necator

Powdery mildew is a fungal pathogen that affects vineyards worldwide. The symptoms of powdery mildew are easier to recognize because of their distinctive appearance. Plants infected with the pathogen display white powdery spots on the leaves and stems. The industry can only tolerate less than 3% on the clusters before off flavors can be tasted in the wine.