Zebra chip (ZC), a newly emerged disease of potato crops, was first recorded to be found in United States in the year of 2000 and currently has spread throughout Central America and southwestern United States. ZC symptoms include discoloration and deformation of potato tubers. Deep stripes are pronounced particularly after symptomatic potato chips are fried, hence the name “Zebra Chip,” which drastically reduce quality and market value. The causal agent of ZC is still unknown; however, presence of the potato/tomato psyllid (Bactericera cockerelli) has been circumstantially associated with the disease. We determined variation in potato/tomato psyllid population through gene sequences, and detected the presence of putative ZC pathogens in this study. Two groups of potato/tomato psyllid were distinguished by genetic analysis and may account for variation in ZC symptom severity. Additional genetic markers of psyllid, particularly salivary gland associated protein genes, were also investigated. X. fastidiosa and bacterium under the group phytoplasma were detected inconsistently in psyllid samples which suggested a non-crucial rule of these pathogens in causing ZC. Nevertheless, presence of psyllid is positively associated with ZC, which suggested psyllid alone may cause ZC. Effects of psyllid toxic saliva on plants and other putative pathogens such as viruses are among future ZC research plans.