Native plants for attraction and support of natural enemies in Michigan highbush blueberry fields
Nathaniel J. Walton, firstname.lastname@example.org, Ariane K. Reister, email@example.com, and Rufus Isaacs, firstname.lastname@example.org. (1) Michigan State University, Entomology, 202 Center for Integrated Plant Systems, East Lansing, MI, (2) Kalamazoo College, Box 602 Hicks Center, Kalamazoo, MI
Conservation strips of native wildflowers were established during 2006 alongside blueberry fields to test the hypothesis that provision of resources for natural enemies increases their abundance and reduces pest abundance in adjacent crop fields. Flowering field borders were compared to a control where the grower maintained a field border management regime of mown grass. Flowering and control perimeters were vacuum sampled for natural enemies throughout 2007. Natural enemies were sorted into major groups and their abundance was compared between flower perimeters and control perimeters. In addition, laboratory cage experiments were conducted to evaluate the ability of native flower species to increase longevity of natural enemies. The longevity of pirate bugs, parasitoid wasps, and ladybeetles provided with excised native flowers was also compared to non-native flower species found in our research sites. Natural enemies were more abundant at the flowering strips than the control side of the field, and of the flowers planted we found natural enemies were most abundant on Solidago juncea (early goldenrod) and Aster laevis (smooth aster). Of the plants tested in the laboratory, both Monarda fistulosa (wild bergamot, native) and Daucus carota (Queen Anne’s Lace, non-native) increased the longevity of natural enemies compared to controls and other tested plants. Measurements of aphid populations on blueberry plants showed reduced colony growth of exposed aphids compared to those that were caged or had a sham cage, but there was no response to proximity to the flowering strips during this first year of flowering by the conservation strip.