Conservation strips of native perennials to enhance beneficial insect abundance in commercial blueberry fields

Conservation strips of native wildflowers were established alongside blueberry fields to test the hypothesis that provision of resources for natural enemies increases their abundance in adjacent crop fields. For two growing seasons (2007 and 2008), at four commercial blueberry farms, these flowering field borders were compared to controls where growers maintained field borders of mown grass. Yellow sticky traps were deployed weekly in field perimeters and along transects into the adjacent fields. Insects on the traps were sorted into major groups and the abundance of natural enemies was compared between fields with flower borders and those without. In 2007, this revealed significant effects of treatment border, distance from border, and time-of-year on natural enemy abundance, with greater natural enemy abundance adjacent to flowering strips. Data from the 2008 growing season has shown similar patterns; fields with flowering borders had more natural enemies and a weaker decline in their abundance with distance from the border. In the context of this data we discuss the multi-year benefit of flowering border strips for improving natural enemy abundance in fruit crops.