ARS | Publication request: Electrical Penetration Graph (EPG) monitoring of feeding by glassy-winged sharpshooter and potential application of EPG to other pathogen vectors

Submitted to: XXI International Congress of Entomology, Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: March 14, 2008
Publication Date: July 6, 2008
Citation: Backus, E.A. 2008. Electrical Penetration Graph (EPG) monitoring of feeding by glassy-winged sharpshooter and potential application of EPG to other pathogen vectors. Abstract No. 1580 in Proceedings of the XXIII International Congress of Entomology CD, Durban, South Africa, July 6-12, 2008.

Technical Abstract: Recent research on feeding of the glassy-winged sharpshooter, Homalodisca vitripennis (Germar) and the exact mechanism of its transmission (acquisition and inoculation) of Xylella fastidiosa (Xf) to grape will be used as an example of the utility of a new, universal, AC-DC Electrical Penetration Graph (EPG) monitor to observe and quantify feeding behavior of piercing-sucking vectors. This presentation will summarize five years of work to identify the transmission mechanism in terms of fluid flow into and out of the vector’s alimentary canal, as recorded by EPG waveforms. The talk will briefly introduce a model of four critical steps to assure success in the acquisition and inoculation process (i.e. vector efficiency). All four steps will be described in detail in an accompanying poster; only the third step will be discussed in this talk. This third step is performance of a specialized inoculation behavior that consists of salivation, ingestion of mixed saliva and plant fluid, followed by two different types of egestion, each from a different area of the anterior foregut. Thus, the mechanism of inoculation is a combination of salivation and egestion. Specific EPG waveforms are correlated with each of these behaviors, and are used to measure how often these behaviors are performed and their durations. Our goal is to develop a resistance index using EPG waveforms alone, for use in development of host plant resistance to the vector. Applicability of this technology to study of blood-sucking arthropod vectors will be discussed.