Submitted to: Southwestern Entomologist
Publication Type: Peer reviewed journal
Publication Acceptance Date: 11/27/2013
Publication Date: 4/10/2014
Citation: Nelson, W.R., Swisher, K.D., Crosslin, J., Munyaneza, J.E. 2014. Seasonal dispersal of the potato psyllid, Bactericera cockerelli, into potato crops. Southwestern Entomologist. 39:177-186. Interpretive Summary: The potato psyllid vectors the bacterium that causes the devastating zebra chip disease of potato in the United States, Mexico, Central America, and New Zealand. Researchers at USDA-ARS Wapato and Prosser in Washington, in collaboration with scientists at The New Zealand Institute for Plant and Food Research, provided information on migration of this insect pest into potato crops. It was determined that, contrary to previous beliefs, local populations of the psyllid significantly contribute to the colonization of potato crops by this insect. Information from this research will help potato producers minimize damage to the potato industry due to this insect pest by monitoring and controlling its local populations.
Technical Abstract: Potato psyllid, Bactericera cockerelli, vectors the bacterium associated with the devastating zebra chip disease of potato in the United States, Mexico, Central America, and New Zealand. A seasonal pattern of appearance of this psyllid in crops from southern to northern regions in the United States is well documented. In this region, potatoes are commonly grown as winter and summer crops in southern and northern parts, respectively. Commercial potato production means there is no plant material available for psyllids at the establishment of each crop and therefore they must migrate into each crop each season. Appearance of psyllids in potato crops commonly starts at an initial focus, often at crop margins or other breaks in the canopy such as irrigation tracks. Psyllids readily jump and fly when disturbed, providing an obvious mechanism for dispersal within a crop. Good experimental evidence also supports longer distance dispersal of potato psyllid, from tens of meters to a few kilometers, most likely by cumulative short distances between suitable host plants within a region. Seasonal infestation observations have often been interpreted as supporting an annual continental-scale migration of the psyllid, although little direct experimental evidence yet exists. Mechanisms for dispersal of potato psyllid over continental distances have been proposed, largely associated with seasonal wind patterns. However, recent overwintering observations in the northern regions of its native zone in the United States and identification of geographically-defined and genetically distinct potato psyllid populations, suggest a static regional status of at least some populations. Thus, a review of migration of potato psyllid into crops is presented herein and a new paradigm for considering overwintering strategies of this psyllid is required.