Electropenetrography (EPG) of a phytoplasma vector, Colladonus montanus reductus

X-disease, caused by Candidatus Phytoplasma pruni, is a serious problem for cherry cultivation in the Pacific Northwest. Colladonus montanus reductus, the most important vector in Washington state, primarily hosts on weeds that grow in the orchard floor and does not host on cherry trees. These weed hosts are also able to be infected with the phytoplasma, and may function as important sources of inoculum. Characterizing electropenetrography (EPG) waveforms of C. m. reductus would help to understand the role that these weeds play in phytoplasma transmission within orchards. Here, we characterize EPG waveforms of C. m. reductus and correlate waveforms with feeding behaviors using salivary sheath staining. Preliminary results show that C. m. reductus readily fed from the phloem of cherry and other weed hosts of the phytoplasma. Additionally, C. m. reductus displayed a presumed X wave on cherry, which indicates sustained ingestion of phloem or xylem and potential host acceptance. Results from this study will allow EPG to be used to address questions on phytoplasma-vector-host interactions within the X-disease pathosystem.