Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/13/2005
Publication Date: 8/1/2005
Citation: Leskey, T.C., Zhang, A., Herzog, M. 2005. Non-fruiting host tree volatile blends: novel attractants for the plum curculio (coleoptera: curculionidae). Environmental Entomology. Env. Ent. Vol 34, Pg 785-793 (2005). Interpretive Summary: The plum curculio is a serious pest of both stone and pome fruit in the eastern United States and Canada. Baited traps have been evaluated to monitor movement of this insect into fruit orchards. Baits have consisted of a single fruit volatile, benzaldehyde and a male-produced aggregation pheromone. However, baited traps have not performed well, likely because of competition from fruit trees which also release benzaldehyde. Therefore, we have created more competitive baits based on volatiles not just released by the fruit, but by the entire tree and specifically by the foliage and woody tissues. In combination with the male-produced pheromone, these novel baits outperformed the standard bait of benzaldehyde and pheromone, even in the competitive environment found within an apple orchard. When benzaldehyde is combined with these new tree-based volatiles and the pheromone, even more plum curculios are captured in traps. These new baits based on volatiles released by the entire tree may lead to effective monitoring tools for the plum curculio.
Technical Abstract: 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 (PCs), Conotrachelus nenuphar (Herbst) (Coleoptera: Curculionidae) in association with black masonite pyramid traps deployed in an unsprayed apple orchard in 2003 and 2004. Synthetic host plant volatiles evaluated included: (1) those identified from foliar and woody tissues of a non-fruiting Stanley plum tree (6-Tree) or the 2 major components (2-Tree); (2) those identified from Stanley plum fruit (7-Plum) or 2 components eliciting positive GC-EAD response from PCs (2-Plum); and (3) benzaldehyde formulated into rubber septa and replaced weekly (Ben(s)), or dispensed into polyethylene vials and replaced weekly (Ben(r)), not replaced (Ben(nr)), and formulated with 10% 1, 2, 4-trichlorobenzene and not replaced (Ben(TCB). In 2003, the greatest numbers of PCs were captured in traps baited with 6-Tree + GA and Ben(TCB) + GA with responses to these baits significantly greater than responses to unbaited control traps. In 2004, the greatest number of PCs was captured in traps baited with 6-Tree(h) + Ben(TCB) + GA with response to this bait significantly greater than responses to unbaited traps. Combined results indicate that volatiles released by foliar and woody tissues of plum are at least as attractive as the single fruit-based attractant, benzaldehyde, when combined with GA and point toward more competitive attractants for PC based on multiple component blends of volatiles released by the entire tree.