A Survey of Beet Leafhopper Populations on Sugar Beets in the Imperial Valley, California, 1953–19581

Abstract

During the dry years covered by the survey (1953-57) most of the beet leafhoppers ( Circulifer tenellus (Baker)) and curly top in the Imperial Valley originated in the cultivated areas. The sugar beet and weeds were the most important host plants. A curly-top outbreak occurred in 1956, a year in which desert populations were low. The beet-leafhopper population and curly-top incidence were greatly reduced in the summer because of the reduction in numbers of host plants. The reduction was increased by establishment of a voluntary beet-free period and a weed host and beet-leafhopper control program. During the comparatively damp season of 1957-58, a moderate population developed in the uncultivated areas, while reproduction was delayed in cultivated areas.