Seasonal Dispersal of the Potato Psyllid, Bactericera cockerelli, into Potato Crops

Abstract. Potato psyllid, Bactericera cockerelli, vectors the bacterium associated with the devastating zebra chip disease of potato, Solanum tuberosum L., in the United States, Mexico, Central America, and New Zealand. A seasonal pattern of appearance of the psyllid in crops from southern to northern regions of the United States is well documented. Potatoes are commonly grown as winter and summer crops in southern and northern parts, respectively, of the United States. No other plant material is available for psyllids when each crop is planted, and the psyllids must migrate into each crop each season. Appearance of psyllids in potato crops commonly starts at an initial focus, often at field 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 cumul...