Progress Report: This is year 4 of a 4 year proposed project for the Washington Grape & Wine Research Program.

Date: January 31, 2014

Project Titles:

  1. Grapevine leafroll associated viruses in Washington State vineyards and the role of the Grape Mealybug and European Fruit Lecanium Scale as vectors.
  2. Biology and Management of Spotted Wing Drosophila in Washington Vineyards

Principal Investigator(s): Doug Walsh & Naidu Rayapati
Collaborator(s): Brian Bahder

Objective(s) of Proposed Research:

  1. Develop commercial-scale demonstration plots using pheromone-based monitoring traps for mealybugs.
  2. Test novel methods for monitoring scale insect populations in the vineyard.
  3. Conduct efficacy studies with reduced-risk candidate insecticides for scale insect control.
  4. Test vineyards that have populations of mealybugs and/or scale insects for the presence of leafroll viruses.
  5. Evaluate the movement of virus-infected mealybugs and scales between vineyards and assess the economic impact of potential transmission and control.
  6. Monitor vineyards for detection of and abundance of spotted wing drosophila and brown marmorated stink bug

Project Summary:

Develop commercial-scale demonstration plots using pheromone-based monitoring traps for mealybugs.

In 2009, field sites were established in the Yakima Valley and Paterson, WA to monitor for the presence of the grape mealybug, Pseudococcus maritimus. This mealybug is the dominant species of mealybug in Washington State vineyards and represents a serious threat to grape growers due to their ability to transmit grapevine leafroll associated viruses. From 2010 to 2012, 30-acre plots were sampled weekly through the growing season and it was determined that one pheromone baited trap per 30 acres of vineyards was adequate to monitor for the presence or absence of the grape mealybug as well as the population phenology. In 2013, pheromone baited lures and sticky traps were distributed to commercial growers willing to collaborate and were placed in vineyards that were infected with leafroll, infested with mealybugs, or both. During the 2013 growing season, growers monitored traps weekly and provided us with information on the status of mealybug populations in their vineyards. All growers found mealybugs in pheromone baited traps and produced data that agreed with that produced from 2010 to 2012 where two distinct flights occurred throughout the season. The occurrence of these flight peaks occurred about two weeks earlier than those that we found from 2010 to 2012, however, this is likely due varying climatic conditions, including a warmer than average winter and a warm spring.

Read more by downloading the full report above.

Pest & Disease //