Pheromone-based monitoring of Pseudococcus maritimus and intra and interspecific vector efficiency of Parthenolecanium corni and Pseudococcus maritimus among and between Vitis x labruscana L. and Vitis vinifera

Grapes have a major economic impact on the state of Washington, which is the number one producer of Concord juice grapes in the United States and the second largest producer of wine grapes in the United States, after California. Due to the importance of grapes to Washington State, there is a very low tolerance to pests and diseases. The most devastating viral disease of grapes, grapevine leafroll disease, was found in Washington State in 2005 and due to the presence of natural vectors Pseudococcus maritimus and Parthenolecanium corni of the associated viruses, a more rapid means of detection and better understanding of the epidemiology of the disease is necessary. The primary objectives of this research are to develop a rapid, cost-effective monitoring program for Ps. maritimus using its sex pheromone and to determine if Pa. corni and Ps. maritimus are capable of transmitting the viruses associated with grapevine leafroll disease between two different species of grape.;To establish an economical means to monitor for Ps. maritimus, three different trapping densities were deployed in various vineyards; one, four, and eight pheromone-baited traps per 12.14 hectares of vineyards. Traps were collected weekly in 2010 and 2011 and adult males were counted. In this project we were able to demonstrate that one trap per 12.14 ha of vineyard was adequate to detect populations of Ps. maritimus so as to make appropriate management decisions.;To determine if both vector species were capable of transmitting this virus between species, a total of 90 bioassays were conducted under greenhouse conditions where first instars of each species was allowed a one week access period on a virus infected plant and were then transferred to a virus free recipient plant for a one week inoculation period. With this research, we were able to demonstrate that both species of vector were capable of transmitting this virus between species of grape under greenhouse conditions and that Ps. maritimus appears to be a more efficient vector than Pa. corni. These results will be important in further understanding the epidemiology of grapevine leafroll disease and how to monitor and control its vectors.