| Abstrakt: |
The mealybug, Ferrisia gilliGullan, attacks important crops such as almonds, grapes, and pistachios in California. In pistachios, F. gillihas 3 generations per year, and a single insecticide application timed to the presence of first instars of the first or second generation provided sufficient control. This strategy has, recently, become less effective, and here we tested the possible explanation that F. gillilife stages are smeared, with different life stages present concurrently, reducing the efficacy of a single pesticide application. We monitored F. gillipopulations and their natural enemies in central California pistachio orchards from 2021 through 2022. We found the first generation of F. gilliwas synchronous, but occurred 3 wk earlier than previously reported. Subsequent generations were smeared. Increased yearly temperatures are a likely explanation for the changes observed in phenology. Almost all natural enemies found were lacewings (n> 10,000). Parasitoids were recovered from pistachios in 2021 (n= 4) and 2022 (n= 164), most were hyperparasitoids. Based on these studies, recommendations are made to monitor F. gilliin early May rather than late May to better target insecticide applications for the first instars. |
