Microscopic Contributions to the Understanding of Glassy-Winged Sharpshooter Feeding Behavior and Host-plant Interaction

The glassy-winged sharpshooter (GWSS), Homalodisca coagulata, is a significant threat to many economically important crops because it vectors the bacterial pathogen Xylella fastidiosa, which causes Pierce’s disease in grapes, variegated chlorosis in citrus, and leaf scorch in oleander and almond. Different strains of the bacteria cause diseases of avocados, peaches, plums, apricots, cherries, alfalfa, and many other trees and ornamentals. The GWSS (Fig. 1) is known to feed on more than 100 species of plants. Knowledge of mouthpart structure is necessary to understand the mechanics of GWSS stylet penetration and stylet movement through host-plant tissues. Thus, we employed a variety of microscopic techniques to describe the morphology and ultrastructure of the sharpshooter mouthparts, determine the characteristics of stylet penetration, reveal the pathway of the stylets from the epidermis of the host plant to the xylem tissue, and establish the ultrastructural damage the stylets cause to host-plant cells.