Biological Notes on Empoasca fabae in Wisconsin

Females of Empoasca fabae (Harris) that were newly dispersed into Wisconsin from areas to the south were caged individually on host plants in the greenhouse. More than half the females began laying viable eggs, thus indicating that the leafhoppers were fertilized prior to their dispersion. Early in the season the sex ratios of most samples ran as high as 4:1 in favor of females. Multiple mating experiments showed that males mated with more than 1 female. The population of the leafhopper declined rapidly to insignificant levels by late September of each year. The last collection dates were November 20, 1956; November 1, 1957; and November 7, 1958.