U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 Crop Diseases, Pests and Genetics Research: Parlier, CA
 close



    Research

                    Research Projects
                                    Publications
                                    Collaborations
                                    News
                People

                    Staff Listing
                                    Careers


        


                    Research Units
                        San Joaquin Valley Agricultural Sciences Center
                                    Commodity Protection and Quality Research
                                    Water Management Research
                                    National Arid Land Plant Genetic RepositorySearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Pacific West Area Parlier, California San Joaquin Valley Agricultural Sciences Center Crop Diseases, Pests and Genetics Research Research Publications at this Location





- ARS National Programs
- Search for a scientific manuscript
- Search for a research project
- ARS Software
- Programs and Projects
- Collaborations
- Subjects of Investigation
- Publications

Title:   Author  item
                                            Wallis, Christopheritem
                                            Krugner, Rodrigoitem
                                            Walse, Spencer
  Submitted to: CDFA Pierce's Disease Control Program Research Symposium
                                    Publication Type: Proceedings
                                    Publication Acceptance Date: 10/11/2010
                                    Publication  Date: 11/17/2010
                                    Citation: Wallis, C.M., Krugner, R., Walse, S.S. 2010. Glassy-winged sharpshooter infestations induce grape hosts to produce volatile compounds which may attract egg parasitoids. CDFA Pierce's Disease Control Program Research Symposium, Dec 15-17, 2010, San Diego, California. p.51.Interpretive Summary: Glassy-winged sharpshooter populations are being controlled, in part, by egg parasitoids, which apparently detect one or more volatile chemicals to find hosts with egg masses. This study examined both GWSS-infested and non-infested grapes to discover which volatile compounds, if any, may be produced by the host as a result of being infested. Early results suggest that at least one compound (putatively identified as 1,8-cineole) was present at higher concentrations around infested plants, and  concentration was significantly correlated with number of egg masses on infested grapes. Following the confirmation of these results, these compounds will be tested for ability to attract parasitoids of GWSS. These results should allow breeders to select cultivars which naturally produce more parasitoid-attracting compounds when infested by GWSS (increasing efficacy of egg parasitism as a management strategy), and to provide a lure to attract egg parasitoids.
                                Technical Abstract: Natural predators or parasitoids may be attracted to prey by specific volatiles emitted from prey-infested host plants. Glassy-winged sharpshooter (GWSS), Homalodisca vitripennis (Germar), is a pest of particular concern as a vector of the Pierce’s disease pathogen, Xylella fastidiosa. GWSS egg parasitoids (e.g. Gonatocerus ashmeadi Girault and related species) are attracted to GWSS-infested plants via olfactory cues. This project evaluated infested grape hosts for production of novel or increased quantities of volatiles that may attract egg parasitoids. In a closed-chambered system, volatile compounds were captured on PorpakQ sorbent over an 8-hour period from grapes that were either infested or not infested with GWSS eggs. Volatile compounds were desorbed into methyl tert-butyl ether and analyzed by gas chromatography. Early results suggest at least one compound (putatively identified as 1,8-cineole) was present in higher amounts around infested plants than non-infested plants, and was positively associated with number of egg masses per plant. This compound subsequently will be examined for ability to attract GWSS egg parasitoids. Discovery of a host-produced compound that attracts parasitoids to GWSS egg masses could affect pest management programs. For instance, breeders could screen for host cultivars that produce higher levels of the parasitoid-attracting compound when infested. The attractant compound also could act as a lure for egg parasitoids, aiding studies that monitor parasitoid numbers.


Return to top


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov