|Munyaneza, Joseph - Joe|
Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/22/2007
Publication Date: 6/4/2007
Citation: Munyaneza, J.E., Crosslin, J., Upton, J.E. 2007. Association of Bactericera cockerelli (Homoptera: Psyllidae) with 'Zebra Chip', a New Potato Disease in Southwestern United States and Mexico. Journal of Economic Entomology, Vol. 100(3): 656-663. Interpretive Summary: Zebra chip, a new defect of potato, has recently been documented in southwestern United States, Mexico, and Central America, and is causing millions of dollars in losses to both potato producers and processors. Scientists at the USDA-ARS at Wapato and Prosser, WA, conducted experiments to determine the insects and potential causal agents involved in this disease. Although the causal agents of this disease were not identified during this study, it was determined that there was a strong association between the potato psyllid and zebra chip. The information from the present study will make it possible for potato producers to focus monitoring and controlling efforts on the potato psyllid and should lead to a reduction in the incidence of ZC and serious losses that this disease causes to the potato crop.
Technical Abstract: A new defect of potato (Solanum tuberosum L.), “Zebra Chip”, so-named for the characteristic symptoms that develop in fried chips processed from affected potato tubers has recently been documented in several southwestern states of the United States, Mexico, and Central America. This defect is causing millions of dollars in losses to both potato producers and processors. Zebra chip foliar symptoms resemble those caused by potato purple top and psyllid yellows diseases. Experiments were conducted to elucidate the association between the potato psyllid (Bactericera cockerelli Sulc.) and zebra chip by exposing this insect to clean potato plants under greenhouse and field conditions. Potato plants and tubers exhibiting typical zebra chip symptoms were tested for the presence of phytoplasmas by PCR. Potato psyllids collected from affected potato fields were also tested for phytoplasmas. Results indicated that there was an association between the potato psyllid and zebra chip. In the greenhouse, 25.8% and 59.2% of tubers exhibited zebra chip symptoms in the raw tubers and fried chips, respectively. In the field, 15% and 57% of tubers showed symptoms in raw tubers and fried chips, respectively. No zebra chip symptoms were observed in tubers harvested from the plants that had not been exposed to psyllids, either in the greenhouse or field cages. No phytoplasmas were detected from potato plants or tubers with zebra chip symptoms, suggesting that these pathogens are not involved in zebra chip. Of the 47 samples of potato psyllids tested for phytoplasmas, only 2 tested positive for the Columbia Basin potato purple top phytoplasma.