Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/18/2012
Publication Date: 8/15/2012
Citation: Swisher, K.D., Munyaneza, J.E., Crosslin, J. 2012. High resolution melting analysis of the cytochrome oxidase I gene identifies three haplotypes of the potato psyllid, Bactericera cockerelli, in the United States. Environmental Entomology. 41:1019-1028.
Interpretive Summary: Potato zebra chip disease (ZC) is caused by a bacterium transmitted to potatoes by the potato psyllid. The disease has caused severe economic damage in Mexico, Central America, New Zealand, the south-central United States. The ZC disease first appeared in the major potato producing region of Washington, Oregon, and Idaho in 2011. Since the ZC bacterium is transmitted by the potato psyllid, understanding the population dynamics of this insect is vital for understanding of the disease epidemiology. Work conducted in California in 2006 suggested there were two biotypes of the potato psyllid in the United States. Our work suggests there are at least three biotypes of this insect in the US. This finding may have implications for the occurrence and spread of ZC disease in the Pacific Northwest.
Technical Abstract: The potato psyllid, Bactericera cockerelli (Sulc) (Hemiptera: Triozidae), is a vector of the bacterium “Candidatus Liberibacter solanacearum,” the putative causal agent of potato zebra chip disease that has seriously affected the potato industry in the Central and Southwestern United States for the past decade. The 2011 potato growing season saw the first report of zebra chip disease in Washington, Oregon, and Idaho; however, B. cockerelli has been recorded in this region every season at least for the past seven years. Studies were conducted to determine the relationship between psyllids collected from the Pacific Northwest potatoes in 2011 and those from the Southwestern and Central United States. High resolution melting (HRM) analysis of the B. cockerelli mitochondrial Cytochrome C Oxidase subunit I-like gene was conducted on over 450 psyllids collected from numerous locations across the Central and Western United States. Results suggest that at least three potato psyllid biotypes exist in the United States, correlating to the Central, Western, and Northwestern United States geographical regions. The HRM analysis results were subsequently supported by DNA sequencing data.