Detection of Xylella fastidiosa in xylem-feeding insects using immunocapture-PCR

Xylella fastidiosa Wells et al. is the causal agent of many plant diseases including those of peach and plum, leaf scorch of oleander, almond, elm, oak, pecan, and sycamore, and Pierce’s disease of grapes. This bacterium is transmitted by xylem-feeding insects. We surveyed Oklahoma for xylem-feeding insects to determine which species commonly occur in vineyards, nurseries, and pecan orchards, and whether any specimens tested positive for the presence of X. fastidiosa. We sampled several locations including three nurseries, seven vineyards, and two pecan orchards in different regions of the state from May until September in 2009 and 2010. Yellow sticky traps were used to sample insect fauna at each location. Insects were removed from cards and screened for the presence of X. fastidiosa using immunocapture-PCR. We found the following sharpshooters in our survey: Xyphon flaviceps, Draeculacephala navicula, Graphocephala coccinea, Graphocephala versuta, Graphocephala hieroglyphica, Cuerna costalis, Oncometopia orbona, Homalodisca vitripennis (Hemiptera: Cicadellidae: Cicadellinae), Prosapia bicincta, and Clastoptera xanthocephala (Hemiptera: Cercopidae). The three most frequently captured species include G. versuta, C. costalis, and O. orbona. Of those insects screened for X. fastidiosa, multiple species have tested positive. These results provide insight into the key species involved in disease transmission in these economically important crops.