02320naa a2200241 a 450000100080000000500110000800800410001910000210006024501020008126000090018330000140019250001210020652015120032765000170183965300200185665300210187665300210189765300210191870000210193970000180196070000170197877300830199516442871993-10-15       1991    bl uuuu     u00u1 u    #d1 aOLDIFIELD, G. N.  aFlight phenology of circulifer tenellus and other leafoppers in San Joaquin Valley citrus groves.  c1991  ap.441-447  aConference of the International Organization of Citrus Virologists, 11., 1991, Riverside, California, Proceedings...  aFlight activity of Circulifer tenellus (Baker) and several other leafhoppers was monitored along the southeastern and southern edges of the San Joaquin Valley of California with yellow sticky cards placed in young and mature citrus groves, and in a sunny rangeland habitat of C. tenellus in 1982 and 1983. The number of C. tenellus trapped in young citrus groves was approximately 35-fold greater than that in mature groves over the 2-yr survey period. Numbers of trapped C. tenellus were at least 10-fold higher in the fall than in the spring, especifically in yuong groves, and remained high for approximatelly 2 months. Although most C. tenellus trapped on stick traps were males, nearly equal numbers of each sex were collected by suction directly from citrus in a young grove. Eight percent of the C. tenellus collected from citrus in the fall were naturally inoculative for Spiroplasma citri, the citrus stubborn disease agent. The high catches of male C. tenellus indicated that males responded differently to stick traps than did females. Many more C. tenellus indicated trapped in the middle of a rangeland breeding site than at the edge of the rangeland next to a mature citrus groves or within the grove. These data indicated that young citrus trees probably receive many more inoculations of S. citri than do trees in mature groves, and that the closed canopy of mature trees may act as an entry barrier to C. tenellus. Overall, Empoasca spp. was the most frequently caught group of leafhoppers.  asticky traps  aBeet leafhopper  aFlight phenology  aSpiroplasm citri  aStubborn disease1 aYOKOMI, R. K. Y.1 aGOLINO, D. A.1 aGUMPF, D. J.  tRiverside, California: International Organization of Citrus Virologists, 1991.