Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: April 1, 2010
Publication Date: November 1, 2010
Citation: Zhu, J.J. 2010. Infochemical-tritrophic interactions of soybean aphids-host plants-natural enemies and their practical applications in pest management. In: Kang, T-X., Liu, L., editors. Recent Advancements in Entomological Research: From Molecular Biology to Pest Management. 1st edition. Beijing, China: Higher Education Press; Springer (joint publication). p. 114-120. ISBN: 978-3-642-17814-6. Available: DOI: 10.2783/b190-001-010-0010-x Interpretive Summary: Soybean aphids, Aphis glycines Matsumura, are newly-invasive aphid pests that have caused significant economic losses to U.S. soybean production. This aphid pest tends to develop large colonies on soybeans, Glycine max, in North America. Since their first being found in Wisconsin soybean fields, they have spread to over 20 US states and southern provinces in Canada. The infestation of this pest whittles soybean growers’ profits and causes hundreds of million dollar losses. The present chapter will mainly describe efforts in studying aphid chemical ecology and sensory physiology for understand how male aphids find their mates and host plants. It will also cover research efforts to understand host plant associated volatiles being used as cues for overwintering host plant location. In addition, findings on how soybean plant defensive system works against aphid infestation, as well as how those induced plant volatiles are used by aphid’s natural enemies for prey location will be presented. Finally, the use the basic understandings for developing useful tools for soybean aphid practical control will be discussed.
Technical Abstract: The newly invasive soybean aphids have seriously threatened U.S. soybean production, and kept haunting many soybean growers by developing large colonies on soybeans in North America since its first appearance in Wisconsin. In 2008, it has spread to over half of US states and southern provinces in Canada. The heavy infestation of this pest whittles soybean growers’ profits and causes hundreds of million dollar losses. In the last five years, my research group has studied soybean aphid chemical ecology, and identified the female pheromone components, (1R,4aS,7S,7aR)-nepetalactol and (4aS,7S,7aR)-nepetalactone from virgin females. At a ratio of 65:35, the trap baited with this blend showed significant attraction to conspecific males and gynoparae. Using pheromone baited trap, we further developed an early warning system that can predict the aphid outbreak. The peak of the trap catch of the winged aphid was 10-14 days ahead of the peak infestation in the soybean field. Further analyses on volatiles emitted from the infested plants revealed that plants are able to produce defensive compounds including methyl salicylate, which is used by aphid predatory insects as chemical cue for prey location. The application of slow-released formulation of this compound in the field has increased yield significantly, compared to the control field.