Pest Status of the Potato Leafhopper on Soybeans in Central Iowa123

Abstract

Population studies and greenhouse experiments were conducted in 1971 and 1972 to determine the status and reproductive factors of Empoasca fabae (Harris) on centra1 Iowa soybeans. Analyses showed that potato leafhopper numbers varied significantly between years and among soybean stages within years. There were no significant differences among fields sampled, and the proximity of alfalfa to soybeans had no significant effect on potato leafhopper numbers collected in the soybean fields. When natural population densities were plotted against economic-injury levels (EIL), the densities did not reach the EIL throughout the soybean growing seasons. A major factor contributing to low potato leafhopper numbers in these pubescent soybeans was low ovipositional rates, as indicated by experimental greenhouse infestations.