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United States Department of Agriculture

Agricultural Research Service

Research Project: EPIDEMIOLOGY AND MANAGEMENT OF XYLELLA FASTIDIOSA (XF) AND OTHER EXOTIC AND INVASIVE DISEASES AND INSECT PESTS

Location: Crop Diseases, Pests and Genetics

Title: Assessing the Post-Winter Threat of Glassy-winged Sharpshooter Populations

Authors
item Johnson,, Marshall - UC RIVERSIDE
item Lynn-Patterson,, Kris - UNIV OF CA, KEARNEY AG CN
item SISTERSON, MARK
item Groves,, Russell - UNIV. WISCONSIN, MADISON

Submitted to: CDFA Pierce's Disease Control Program Research Symposium
Publication Type: Proceedings
Publication Acceptance Date: October 9, 2007
Publication Date: December 12, 2007
Citation: Johnson,, M.W., Lynn-Patterson,, K., Sisterson, M.S., Groves,, R. 2007. Assessing the Post-Winter Threat of Glassy-winged Sharpshooter Populations. In: Proceedings of the Pierce's Disease Research Symposium, December 12-14, 2007, San Diego, California. p. 34-37.

Interpretive Summary: Glassy-winged sharpshooter (GWSS), the most important vector of Pierce’s disease in California, is currently found only in southern portions of the state. Spread of the glassy-winged sharpshooter north is a serious threat to grape production on the north coast. Suitability of the north coast climate for glassy-wing sharpshooter overwintering survival is currently unknown. Prior research indicates that GWSS adults cannot feed at maximum daily temperatures below 50°F, thereby reducing its ability to survive cold winters. We will verify the impact of cool temperatures on GWSS adults by exposing them to a regime of seasonal temperatures (within temperature cabinets) that reflect some of the marginal areas where we expect GWSS to poorly survive California winters. Subsequently we will use historical temperature records to construct maps to delineate areas where post-winter GWSS mortality should be substantial, thereby providing a tool to estimate the springtime GWSS threat to different regions. This research will help establish which portions of California are suitable for year round survival of the GWSS.

Technical Abstract: After glassy-winged sharpshooter (GWSS), Homalodisca vitripennis, arrived in California, it was believed that the insect would establish throughout much of the northern agricultural production areas. However, GWSS appears to be limited to discrete regions within the San Joaquin Valley where winter temperatures are mild and the temperature rarely drops below freezing. Prior research indicates that GWSS adults cannot feed at maximum daily temperatures below 50°F, thereby reducing its ability to survive cold winters. We plan to verify the impact of cool temperatures on GWSS adults by exposing them to a regime of seasonal temperatures (within temperature cabinets) that reflect some of the marginal areas where we expect GWSS to poorly survive California winters. The goal of the study would be to determine the ability of GWSS adults to survive winter conditions around the state by subjecting GWSS adults to low temperatures with daily temperatures below 10°C and nightly temperatures above 0°C. Using temperature records to calculate numbers of cooling degree days, we plan to construct maps to delineate areas where post-winter GWSS mortality should be substantial, thereby providing a tool to estimate the springtime GWSS threat to different regions. If successful, post-winter GWSS survival maps could be produced each spring (e.g., April) that would provide estimates of where GWSS populations should be absent or minimal because of winter conditions.

Last Modified: 8/27/2014
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