Origins of Potato Leafhoppers (Homoptera: Cicadellidae) Invading Potato and Snap Bean in Minnesota

Publisher Website
Google Scholar
Abstract
Changes in potato leafhopper, Empoasca fabae (Harris), stage distribution on potato and snap bean were examined in 1984–1985 with the objective of determining whether invasions were of local or long-distance origin. E. fabae populations were routinely sampled in potato and snap bean fields emerging after first E. fabae arrival in Rosemount, Minn. (4 June in 1984,9 May in 1985,0 cumulative degree days [CDD], base 8.4°C). Adults were first consistently collected on potato and snap bean 325–475 CDD in 1984, and several large influxes occurred 355–494 CDD in 1985. These invasions occurred when first-generation E. fabae would have matured on undisturbed hosts, suggesting they were of local origin. With the first large increase in E. fabae numbers, there was a shift in sex ratio (data available for 1985 only) from predominantly female to 50:50. There is some evidence for dispersal following harvesting or plowing of alfalfa, but invasion correlated best with heat unit accumulations sufficient for the development of F1 progeny.