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International Conference on Mathematical Biology and

Annual Meeting of The Society for Mathematical Biology,

July 27-30, 2009

University of British Columbia, Vancouver

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Program

Poster PS58B
Jeong-Mi Yoon
University of Houston-Downtown
Title A Canonical Correspondence Analysis for representing the relationship between xylem fluid-feeding insect populations and their environmental variables involved with Pierce's Disease in Vineyards of Texas
Abstract Pierce’s disease (PD) of grapes is caused by Xylella fastidiosa (Xf), a plant pathogen that multiplies inside the xylem (water-conducting vessels) leading to blockage, drought symptoms and death. Sharpshooter insects, which feed on xylem sap, transfer the bacterium from plant to plant. PD has had negative effects on the California wine industry and is a serious concern for the growing Texas wine industry. As such, the USDA has funded a large study of the spatial and temporal distribution of insect species around Texas through the Texas PD Research and Education Program. The resulting data base of insect trapping numbers from vineyards includes thousands of rows of data and valuable environmental variables. The objective of this study was to analyze the optimal representation of the association between the vineyard sites, the sharpshooter frequencies and the related the environmental variables using a multivariate analysis called to Canonical Correspondence Analysis (CCA) using statistical software, XLSTAT. This presentation will focus on the qualitative analysis of the representation of the CCA plots based on the principal eigenvalues and the weighted correlation coefficients between ordination axes and environmental variables. Our data set consists of three dominant insects’ frequencies, environmental variables (i.e. elevation, precipitation, cold hardiness and eco-regions) at 40 different vineyard sites simultaneously. The insect frequencies were obtained by dividing the insect counts by the trapped days at each site and averaging it by using the total trapped samples at each site. This analysis suggests some novel ecological associations about Texas sharpshooter species. This research is a part of the ‘Interdisciplinary Training for Undergraduates in Biological and Mathematical Sciences (UBM)’which is funded by NSF.
CoauthorsLisa Morano, Mitchell Forrest, Isabelle Lauziere, Ali Abedi, Danil Safin, Audrey Gonzales
LocationWoodward Lobby (Wednesday-Thursday)