ARE GLASSY-WINGED SHARPSHOOTER POPULATIONS REGULATED IN CALIFORNIA? LONG-TERM PHENOLOGICAL STUDIES & CONSTRUCTION OF MULTI-COHORT LIFE TABLES FOR THE GLASSY-WINGED SHARPSHOOTER IN CITRUS ORCHARDS

Glassy-winged sharpshooter (GWSS; Homalodisca vitripennis; formerly H. coagulata) population densities have been steadily declining over a 4.5 year period in organic lemons grown in an experimental study plot at University of California, Riverside Ag. Ops. Peak adult GWSS populations in August 2006 were just 32 % of those observed around August 2002. It is uncertain if egg parasitism, which has consistently averaged ~ 20 % per year of GWSS egg masses, is responsible for the observed decline. Density dependent analyses of time series data are planned once data sets are large enough. Phenological observations are being complimented with recently initiated multi-cohort stage frequency life tables to provide greater insight into GWSS population dynamics and identification of life stages most susceptible to mortality factors