Feeding bebavior is fundamental in the process of phytophagous insect diversification (Caillaud & Via, 2000). The feeding bebavior of phytophagous insects is responsible for both direct damage and the transmission of pathogens. Planthoppers are a biogeographically diverse, monophyletic clade with about 12,000 described species grouped into 18 families (O'Brien, L.B. 2002; Stroinski A& Szewedo J., 2002). About 30 species of planthoppers are reported as vectors of plant pathogens, in such familes as Delphacidae, which transmit viruses (Nault & Ammar, 1989), or Cixiidae, which transmit phytoplasmas (Purcell, 1985). Transmission of circulative and non-circulative pathogens depends on stylet