Improved Control of Curculio caryae (Coleoptera: Curculionidae) through Multi-Stage Pre-Emergence Applications of Steinernema carpocapsae

Abstract

Abstract The pecan weevil, Curculio caryae (Horn), is a key pest of pecan in North America. Entomopathogenic nematodes have potential as alternative control agents for C. caryae. In prior studies, when single applications of entomopathogenic nematodes were applied during adult weevil emergence, only moderate efficacy was observed. The objective of this study was to determine the compounded impact of multistage nematode applications on C. caryae mortality over a 2-year period. Experiments were conducted in a pecan orchard in Byron, GA. In the fall of 2007, freshly-emerged C. caryae larvae were placed in pots under the tree canopy. The nematode, Steinernema carpocapsae (Weiser), was applied 3 times in spring through fall of 2008 (targeting C. caryae larvae) and 3 times during the spring and summer of 2009 (primarily targeting adults). The percentage of surviving C. caryae was determined in the fall of 2008 and 2009, approximately 1 and 2 years after larvae emerged. In 2008 (1 year postemergence), the number...