Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/14/2013
Publication Date: 4/1/2013
Citation: Swisher, K.D., Munyaneza, J.E., Crosslin, J. 2013. Temporal analysis of potato psyllid haplotypes in the United States. Environmental Entomology. 42:381-393.
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 earlier work suggested there are at least three biotypes of this insect in the US. In this paper we examined the genetic make up of archived potato psyllid samples dating from 1998 to 2010. Results indicate that the novel "northwestern" haplotype we previously identified was present in the Pacific northwest as early as 1998. This finding may have implications for the occurrence and spread of ZC disease in the Pacific Northwest and elsewhere in the US.
Technical Abstract: The potato psyllid, Bactericera cockerelli (Sulc) (Hemiptera: Triozidae), is an economically devastating pest of potato crops across the United States, as it is known to cause psyllid yellows disease and to transmit the bacterium that causes zebra chip disease. A recent genotyping study of B. cockerelli collected during the 2011 potato growing season identified three psyllid haplotypes within the western and central United States according to their geographical regions: Northwestern, Western, and Central. To understand potato psyllid population dynamics prior to the year 2011, high resolution melting analysis of the B. cockerelli mitochondrial cytochrome oxidase I-like gene was used to identify the haplotypes of over 450 archived individual psyllids collected in the western and central United States between the years 1998 and 2010. Results show that the Northwestern haplotype was present in Washington State as early as 1998 and has persisted in this region since that time. Likewise, psyllids of the Western haplotype have also been present in Washington and Oregon prior to 2011, showing fluctuations in 2009 and 2010. These results were supported by DNA sequencing analyses.