The continued growth of cropland and loss of natural habitat have increasingly simplified agricultural landscapes in the Midwest.
In a study supported in part by the National Science Foundation's (NSF) Kellogg Biological Station Long-Term Ecological Research (LTER) site in Michigan--one of 26 such NSF LTER sites around the world--scientists concluded that this simplification is associated with increased crop pest abundance and insecticide use.
"This research suggests that there are simple ecological solutions--such as preservation or restoration of semi-natural lands within large agricultural regions--that could reduce the need for insecticides and contribute to agricultural economies," says Nancy Huntly, NSF program director for the network of LTER sites.
While the relationship between landscape simplification, crop pest pressure and insecticide use has been suggested before, it has not been well supported by empirical evidence, scientists say.
Results of the study, published in this week's issue of the journal Proceedings of the National Academy of Sciences, are the first to document a link between simplification and increased insecticide use.
"When you replace natural habitat with cropland, you tend to get more crop pest problems," says lead author Tim Meehan, an entomologist at the University of Wisconsin-Madison (UW-Madison).
He and other authors are affiliated with the Great Lakes Bioenergy Research Center, one of three U.S. Department of Energy Bioenergy Research Centers, and with NSF's Kellogg Biological Station LTER site.
"Two things drive this pattern," says Meehan. "As you remove natural habitats, you remove habitat for beneficial predatory insects, and when you create more cropland you make a bigger target for pests--giving them what they need to survive and multiply."
Because landscape simplification has long been assumed to increase pest pressure, Meehan and collea
|Contact: Cheryl Dybas|
National Science Foundation