The spatial ecology of Empoasca fabae is reviewed with special reference to the temperature and humidity tolerance, and flight behavior. The overwintering range is severely temperature limited, and its summer range is partially humidity limited. During spring the range expands northwards as far as Canada along the “Mississippi Flyway” Potato leafhopper populations in Louisiana decline during the summer and reach their highest levels in the northern states by midsummer, and then decline quite rapidly in early fall. Evidence is presented that this is due to emigration in the northerly airflows behind cold fronts crossing the country west to east. Such airflows may be sufficient to return some potato leafhoppers to their overwintering grounds in Louisiana.