The sugar-beet industry of Utah, and many other western states, has suffered enormous losses from curly-top. Under natural conditions this disease is transmitted, so far as known, solely through the feeding of the beet leafhopper, Eutettix tenellus (Baker), the so-called "white fly." The serious damage of 1924 and 1926 has especially emphasized the necessity for more knowledge concerning the problem.
Knowlton, George F., "Bulletin No. 205 - The Beet Leafhopper in Utah: A Study of Its Distribution and the Occurrence of Curly-top" (1928). UAES Bulletins. Paper 176.