GLASSY-WINGED SHARPSHOOTERS (GWSS) POPULATION DYNAMICS AS A MEANS OF GAINING INSIGHT INTO THE MANAGEMENT OF GWSS POPULATIONS

• Author(s): Luck, Robert; Andersen, Peter; Coviella, Carlos; Hoddle, Mark; Mizell, Russell;
• Abstract: Our results indicate that: 1. Glassy-winged sharpshooter (GWSS) populations in untreated groves at University of California, Riverside (UCR) Agricultural Operations have been declining steadily since the beginning of 2002 through mid 2005 when sampling ceased. Current population densities are only 10% as dense as those during 2001-2002. 2. Forecast analysis indicates that, if current trends continue, untreated GWSS populations should decrease to their minimum densities sometime after winter 2008 and prior to summer 2013, depending on the Citrus species on which they are feeding. 3. Forecast analyses indicate that adult GWSS densities are cycling around an equilibrium density of 600 adults per Valencia tree and 950 adults per lemon tree when left untreated. 4. Population analyses indicate that 30% of the first instar nymphs survive to become fifth instar nymphs and less than 15% become adults on the citrus cultivar. Egg mortality is not included. 5. Current estimates of GWSS impact on citrus production and fruit quality is an overestimate because the GWSS densities under which these measurements were made are 9 to 25 times more dense per tree than those that currently prevail in most untreated commercial orchards.
• Publication Date: Dec 2005
• Journal: 2005 Pierce's Disease Research Symposium