Location: Vegetable Crops ResearchTitle: Using plant volatile traps to estimate the diversity of natural enemy communities in orchard ecosystems Author
Submitted to: Biological Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/21/2016
Publication Date: 5/4/2016
Publication URL: http://handle.nal.usda.gov/10113/63257
Citation: Mills, N.J., Jones, V.P., Baker, C.C., Melton, T.D., Steffan, S.A., Unruh, T.R., Horton, D.R., Shearer, P.W., Amarasekare, K.G., Miliczky, E. 2016. Using plant volatile traps to estimate the diversity of natural enemy communities in orchard ecosystems. Biological Control. 102:66-76. doi: 10.1016/j.biocontrol.2016.05.001. Interpretive Summary: Biological control is a foundational component of pest management. Here, we have shown that plant volatile traps can be used as an effective tool for monitoring the biodiversity of natural enemy communities in western orchard crops. Predator communities in these western orchard systems were significantly more diverse than previous studies of orchard systems. Differences among orchards and years were noted, but overall, natural enemy communities tended to be similar among the western orchards. For the full benefits of plant volatile traps to be realized in monitoring natural enemy communities, it will be necessary to establish a causal linkage between biodiversity and biological control efficacy.
Technical Abstract: Increasingly, evidence supports a strong linkage between biodiversity and ecosystem functioning. Biological control, an important ecosystem service, is known to be influenced by the biodiversity of local natural enemy communities. As part of a large, multi-state, project we investigated the use of plant volatile traps for monitoring the biodiversity of natural enemies in orchard crops in the western U.S., and here we present a comparative study of spatial variation among orchard crops and temporal variation through the growing season. In the absence of previous research on this topic, our hypotheses were: 1) that natural enemy biodiversity would be comparable between different orchard crops within the western region, and 2) that natural enemy biodiversity would increase to a maximum mid-season and subsequently decline through the rest of the season. Our analysis from 34 orchards over the two-year sampling period showed a surprisingly high level of similarity in the predator communities between orchard crops and locations, matching our initial hypothesis, with most predator genera shared among all the communities sampled. In the apple, cherry, and pear orchards, natural enemy diversity tended to increase through the growing season; our second hypothesis, therefore, was not entirely supported. Ultimately, successful enhancement of ecosystem services such as biological control will require not only a solid understanding of predator community composition, but also the functional diversity therein. Accurate censuring of the resident predator fauna is the first step in the process, and plant volatiles represent effective tools for this purpose.