Submitted to: Annual Cumberland Shenandoah Fruit Workers Conference
Publication Type: Proceedings
Publication Acceptance Date: 3/1/2006
Publication Date: 7/25/2006
Citation: Leskey, T.C., Zhang, A. 2006. Impact of prevailing temperatures on captures of plum curculio in odor-baited traps. Annual Cumberland Shenandoah Fruit Workers Conference. p.56.
Technical Abstract: In 2003-2005, we evaluated the attractiveness of novel synthetic host plant volatiles alone and in combination with the synthetic aggregation pheromone, grandisoic acid (GA) to overwintered adult plum curculio, Conotrachelus nenuphar (Herbst) (Coleoptera: Curculionidae) in association with black masonite pyramid traps deployed in an unsprayed apple orchards. Based on captures in baited and unbaited traps, we hypothesized that the cooler conditions experienced during the plum curculio trapping period in 2005 reduced the release rate of synthetic odor baits to the point where they were no longer perceptible to foraging plum curculios. Average daytime temperatures for 2003, 2004, and 2005 were 15.88 degrees C, 20.59 degrees C, and 13.61 degrees C, respectively. Gravimetric studies revealed that release rates for lures were reduced by approximately 35-50 percent in 2005 compared to 2004. Based on analyses of field data collected between 2003-2005, we have found that there is a significant relationship between temperature and captures in odor-baited traps and that the threshold for plum curculio activity associated with baited traps is between 12-14 degrees C. Only at temperatures above this threshold do we see benefit of lures associated with traps. This temperature threshold is higher than that associated with plum curculio activity in the field, and therefore helps explain some of the variability associated with trap captures and reason for their poor predictive abilities.