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Glassy-Winged Sharpshooter Population Survey and Xylella fastidiosa Detection Candice A. Sanscartier 1 , Arinder K. Arora 2 , Genet M. Tulgetske 2 , Thomas A. Miller 2 1 Department of Bioengineering 2 Department of Entomology University of California, Riverside ABSTRACT Across the United States from California to Florida and as far north as Virginia, grapevines are succumbing to Pierce’s Disease (PD) which currently infects more than 30% of grapevines and is a threat to the $30 billion wine industry. PD is caused by the bacterial pathogen, Xylella fastidiosa, which blocks water from flowing through the xylem of plants. Affected grapevines develop leaves that are discolored and dried out, and usually die within 2-5 years. X. fastidiosa is transmitted by xylem feeding insects. The most effective insect vector is a leafhopper, Glassy-Winged Sharpshooter (GWSS, Homalodisca vitripennis). GWSSs are able to survive in mild to scorching temperatures and can feed on the woody stems of plants, making them an optimal vector of the pathogen. In the summer, GWSS populations explode, creating the greatest period of X. fastidiosa infection of grapevines. During summer, 2010, we performed a survey on unsprayed grapevines on the UCR campus to determine patterns of GWSSs visiting the plants and their infection status. Insects were collected on yellow sticky traps from late June to late October. All insects were surface sterilized, the DNA was extracted, and real-time PCR was used to test for presence of X. fastidiosa. GWSS visitation to the plants was highest in midsummer. From 112 insects collected, 83 were tested for X. fastidiosa and approximately 76% were found to be positive. These results indicate that many of the GWSSs feeding on the unsprayed grapevines are infected with X. fastidiosa, placing the plants at high risk of infection. Mentors Faculty Mentor: Thomas A. Miller (top) Graduate Student Mentor: Arinder Arora (lower left) Postdoctoral Mentor: Genet M. Tulgetske (lower right) Department of Entomology Candice joined my laboratory as a volunteer shortly after she took my Freshman Advising Seminar in Fall of 2009. From the beginning, Candice fit into our lab very well. She learned quickly from Lab Manager Genet Tulgetske, and soon came to be reliable and dependable so we hired her part time. After becoming familiar with our projects, she selected one, Pierce’s Disease of grapevines, and asked if she could work on that on her own. She monitored the population of the vector insect, Homalodisca vitripennis, a leafhopper, and provided reports to the granting agency. Now in her third year, Candice received grant support from the campus’ <strong>Undergraduate</strong> <strong>Research</strong> Grants and other scholarships. She is also mentoring other undergraduates who followed her example. She does PCR analyses for the presence of the pathogen in the vector insects causing Pierce’s Disease in our research vineyard at Agricultural Operations. At the 2012 UCR Symposium for <strong>Undergraduate</strong> <strong>Research</strong>, Scholarship, and Creative Activity, a grape and wine industry representative praised her poster as work that was critically important to the industry. Candice caught the research “bug” early on and is planning to attend graduate school. As a junior, she already acts and talks like a graduate student and now, is publishing. She has a very bright future. A U T H O R Candice A. Sanscartier Bioengineering Candice Sanscartier is a junior majoring in Bioengineering. She is an active member and upcoming officer of the Biomedical Engineering Society. Candice joined Dr. Miller’s entomology lab as a freshman majoring in Biology. She changed her major to Bioengineering, although continued to work in Dr. Miller’s lab. During her freshman year, she worked under the mentorship of graduate student, Arinder Arora, investigating symbiotic control of Pierce’s Disease, caused by the bacterium, Xylella fastidiosa. She then initiated her own project using molecular and field techniques to survey Glassy-Winged Sharpshooter population patterns and infection rates in local Southern California grapevines. Candice was awarded two UCR <strong>Undergraduate</strong> <strong>Research</strong> Grants to support her research and presented her results at multiple symposia and conferences. Candice thanks her mentors, Dr. Miller, Arinder Arora, and Dr. Genet Tulgetske for their guidance and encouragement. U C R U n d e r g r a d u a t e R e s e a r c h J o u r n a l 3 1